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Case-hardening steels by sdsdfqw21

VIEWS: 570 PAGES: 52

									  EDELSTAHL WITTEN-KREFELD GMBH




 CARBODUR
  CARBODUR                        Engineering steels



CARBODUR
 CARBODUR
        CARBODUR
         CARBODUR
                Case-hardening steels
Contents
Page 4 – 7      Carbodur – The material
Page 8 – 9      Energy industry
Page 10 – 11    Transport
Page 12 – 13    General mechanical engineering
Page 14 – 15    Steel portraits
Page 16 – 17    Steel production
Page 18 – 19    Steel processing




Material data
Page 20 – 31    Material Data Sheets
                (Please note the text on the flap of the rear cover, which contains

                information on the Material Data Sheets)




Technical information
Page 32 – 36    Hardenability
Page 37 – 39    Machining and heat treatment
Page 40 – 43    Case-hardening treatment
Page 44         Overview of grades and chemical composition
Page 45         Melt analysis/International standards
Page 46         Forms supplied
Page 47         Hardness comparison table
Page 48         Temperature Comparison
Page 50         List of photos

                                                                                      3
CARBODUR


                 Hard case, tough core –
                            gets to grips
How long a component stands up
to demands, and how reliably it
withstands peak stresses, de-
pends on the material the compo-
nent is made of. In the final analy-   In terms of non-metallic inclu-
sis, the load-bearing capacity of a    sions, the purity of these steels is
small part determines the cost-        higher than that of normal quality
efficiency of large machines or        steels. They also respond more
installations.                         uniformly to heat treatment.
The more carefully the material is     Through precise adjustment of
tailored to the function of the re-    the chemical composition and the
spective components, the more          use of special production and test
efficient the entire system is.        conditions, we are in a position to
Edelstahl Witten-Krefeld is the        supply you with steel grades
specialist for producing high-         manufactured with a wide variety
grade steels with highly specific,     of processing and service proper-
precisely defined properties.          ties. Following carburising and
The group of case-hardening            hardening of the surface, case-
steels marketed under the brand        hardening steels display great
name Carbodur is evidence of the       hardness and wear resistance in
leading international position of      the region of the surface layer,
Edelstahl Witten-Krefeld in the        while the strength and toughness
field of high-strength, high-grade     of the base material are retained
steels.                                in the core.
The case-hardening steels pre-
sented in this brochure are un-
alloyed and alloyed special
engineering steels with relatively
low carbon contents of roughly
0.10 to 0.25%.


  4
Carbodur
with wear problems
                                    Consequently, case-hardening
                                    steels or case-hardened compo-
                                    nents are indispensable wherever
                                    high wear resistance, high fatigue
                                    strength and low notch sensitivity
                                    are required.
                                    The choice of a steel grade is
                                    governed by the intended appli-
                                    cation, the types of stress in-
                                    volved and the dimensions of the
                                    parts or the geometry of the com-
                                    ponents in question. Technical
                                    and economic aspects are like-
                                    wise of decisive importance. Our
                                    materials specialists are available
                                    for consulations concerning the
                                    optimum choice and most expe-
                                    dient use of the various case-
                                    hardening steel grades.




    Carbodur –   unbeatable for

                   hardness       and   durability
                                                                      5
Maximum purity                         nickel-chrome-molybdenum case-        High fatigue strength
The strength and toughness of          hardening steels and chrome-          Inherent compression stresses
the base material are determined       nickel-molybdenum case-harden-        arise in the surface layer when
by its chemical composition and        ing steels.                           case-hardening a component.
the heat treatment it undergoes.       The great hardness and the            These stresses counteract the
Consequently, the required prop-       fatigue strength of the surface       external stresses, which are
erties of the steel are already spe-   layer are achieved by the case-



                                                                                 Spot-on
cifically targeted when first melt-    hardening treatment, i.e. by car-
ing the steel. The facilities in       burising, hardening and temper-
Witten and Krefeld permit a highly     ing (or stress relieving). If, for
accurate and reliably repeatable
chemical composition. An ex-
                                       example, high strength is required
                                       in combination with high tough-             right
tremely high degree of purity is       ness of the core, the alloying ele-
achieved by the spot-on melt           ments must be matched in such a
analysis, secondary metallurgical      way that through-hardening is
treatment and vertical continuous      guaranteed at a given cross-sec-
casting, or alternatively by remelt-   tion and with the given heat treat-
ing. Non-metallic inclusions are       ment. This steel-specific through-
virtually ruled out.                   hardening is offered by Carbodur,
The high degre of macroscopic          even at large cross-sections.
and microscopic purity, the            We are in a position to offer you
homogeneity of the microstruc-         case-hardening steels manufac-
ture and the fine-grain stability of   tured specifically with the hard-
our Carbodur grades cannot be          ness you require. Make use of
beaten by any other manufacturer       this opportunity - talk to our
of high-grade steels.                  materials specialists!


Controlled hardenability               High fine-grain stability
The selection of appropriate al-       The targeted adjustment of the
loying elements permits targeted       aluminium and nitrogen contents
control of the hardenability of the    of our Carbodur steels results in
base material and the hardenabil-      outstanding fine-grain stability.     mostly of a tensile nature, and
ity of the carburised surface layer.   Thanks to this high fine-grain sta-   thus increase the fatigue strength.
In addition to unalloyed case-         bility, our steels are particularly   In addition to their extraordinary
hardening steels, we also offer        suitable for the direct hardening     wear resistance, components
the following alloyed versions:        of components, a process carried      made of Carbodur steels are thus
manganese-chrome case-harden-          out at high temperatures. Coarse-     characterised by very high
ing steels, molybdenum-chrome          grain or mixed-grain steel would      strength under dynamic loads
case-hardening steels, nickel-         result in non-uniform distortion      once they have been hardened.
chrome case-hardening steels,          and reduced toughness.                However, case-hardened compo-


  6
                                                                           efficiency of series production is
                                                                           already defined when ordering the
                                                                           steel. The machinability of case-
                                                                           hardening steels is influenced by
                                                                           the microstructure, the strength
                                                                           and the non-metallic inclusions




– Carbodur has just the
chemstry for you                                                           (sulphides, oxides) that may be
                                                                           present. The machinability of the
                                                                           steel can be further optimised by
                                                                           increasing the amount of sulphid-
                                                                           ic inclusions, by calcium treat-
                                                                           ment and by appropriate heat
                                                                           treatment, i.e. by specifically ad-
                                                                           justing the microstructure.


                                                                           Made-to-measure heat
                                                                           treatment
                                                                           Depending on the intended appli-
                                                                           cation and processing, we can
                                                                           supply you with Carbodur steel
                                                                           grades in a wide variety of treated
                                                                           conditions, e.g. with reduced
                                                                           hardness, maximum hardness or
                                                                           a specific hardness range, treated
                                                                           for ferrite-pearlite structure or for
                                                                           spherical carbides.
                                                                           Detailed technical information on
 nents also have to demonstrate        Good machinability                  forms supplied and machining
 the highest possible ductility        The larger the quantity of compo-   can be found from Page 32
 when exposed to high dynamic          nents to be manufactured, the       onwards.
 stresses, in order to avoid brittle   more important the demand for
 fractures. As the impact strength     good machinability of the materi-
 of the component decreases with       al. This means that the economic
 increasing case-hardening depth,
 the latter must not be too great.




                                                                                                              7
The world of Carbodur steels is
                                                           More staying
the world of drive systems. Their
strengths are in demand wherever                          with Carbodur
power is transmitted. The indi-
vidual components of the mighty
transmission mechanisms used in
hydroelectric power stations, wind
turbine generators or in the off-
shore industry not only have to
withstand enormous pressures per
unit of area, they also have to run
constantly and untiringly. This calls
for wear resistance and fatigue
strength. Precision gear wheels
made of Carbodur in the propeller
drives of drilling rigs and turbine
gears of power stations reliably        Here, the emphasis is not so much
withstand the stresses and, thanks      on resistance to impact and shock
to their wear resistance, reliably      loads as on hardness and core
guarantee the dimensional stability     strength. Our chrome/nickel or
of the components. Safety takes         chrome/nickel/molybdenum-
top priority in the mining sector.      alloyed Carbodur grades, for ex-
The underground extraction equip-       ample, offer the best prerequisites
ment essentially works non-stop         for meeting the stringent require-
without a break. Malfunctions           ments. Our Carbodur 17 CrNi 6-6
brought about by the failure of         and Carbodur 18 Cr NiMo 7-6
transmission components not only        grades, for instance, are particu-
mean expensive interruptions in         larly suitable for relatively large
production, but also increase the       cross-sections.
safety risk.




  8
                                         Energy industry




power –
case-hardening steels




   Carbodur –
        takes   more,   lasts   longer
                                                           9
                         Carbodur – the winner
                                        comes
Just as there is a wide variety of     long periods, and must also be
demands on the components for          capable of absorbing sudden
different types of vehicle, we also    blows and shocks without losing
have a wide variety of options for     any teeth. The case-hardened
precisely adapting our Carbodur        parts have to display a combina-
steels to suit the prevaillign re-     tion of wear resistance and fatigue
quirements. The suitable material      strength in the surface layer and
for the components is selected         impact strength in the core zone.
with a view to safety, economic        Safety takes top priority in the
efficiency and a long service life,    passenger transport sector. Con-
or the ability to withstand extreme    sequently, the specific properties
stresses for short periods.            of Carbodur steels are particularly
The differential of a Formula 1 car,   advantageous for engines and
for example, only has to withstand     gearboxes in automotive engi-
stress for a relatively short time -   neering. They can be used, for
the duration of a race (at least!).    example, in piston pins, speed
On the other hand, it is exposed to    change gears, drive shafts, coun-
extreme stresses for short periods     tershafts, synchroniser bodies,
of time as a result of the enormous    ring gears, differential bevel gears,
torques transmitted. Carbodur          bevel pinions and differential side
steel can be specifically “tuned” to   gears.
cope with this task.
In contrast, the gear wheels of a
truck that works under the tough
conditions of a building site have
to take constant punishment over


 10
                                        Transport




when it
to extreme stresses




         Carbodur – hard      for the   moment
               and for the   duration
                                                    11
        Carbodur case-hardening
                the prescription
Maximum precision on the one
hand, and maximum sturdiness on
the other – two different require-
ments, but always one task for          good idea to use the same steel in
Carbodur. In terms of precision, a      heavy-duty transmissions, e.g. in
printing press is like a giant clock-   the mining industry or in an exca-
work: screen resolutions of as little   vator, if only because of the larger
as 0.01 mm are required in order        dimensions or the machines, or of
to produce the finest prints. The       the gear wheels and other compo-
numerous gear wheels of the indi-       nents. The drivelines of mining
vidual printing units have to be        machines and construction ma-
manufactured to very close toler-       chinery have to withstand gigantic
ances. Wear means play in the           stresses. A breakdown caused by
wheelwork and impairs the quality       a broken tooth, for instance, can
of the resultant prints. Therefore,     cause expensive production stop-
the gear wheels and the individual      pages. Edelstahl Witten-Krefeld
assemblies of high-quality printing     not only supplies you with the         und
presses have to be manufactured         optimum steel grade for large
using a steel grade that is already     cross-sections, or bar stock with
melted to have a specific chemical      large dimensions, but also acts as
composition catering to the re-         your extended workbench, as it
quirements, or that is produced for     were, by providing pre-machined
specific hardenability. The steel, or   parts, such as pre-drilled disks.
the individual components, must         Talk to our specialists about these
be strong at the core, while the        options.
surface layer must withstand any
wear whatsoever. And it has to do
so at very high speeds and for
years on end. It would not be a


 12
                                           General mechanical engineering




 steels –
 against bad teeth




   Carbodur –   für den   Moment
d auf   Dauer




                      Prevention with   Carbodur –
                                 better than   false teeth

                                                                  13
                                                                               • Carbodur C 15 E/Carbodur C 15 R

                                                                               Unalloyed case-hardening steel for com-

                                                                               ponents in mechanical and automotive

                                                                               engineering with low core strength, pri-

                                                                               marily for wear stresses, such as levers

                                                                               and shafts.




How would you like it –
                 whole or
Large cross-sections
Carbodur – definitely not run-of-
the-mill, but specifically tailored to
your needs. Each of the basic
grades briefly outlined here can
be heat treated at the factory to
adapt it for optimum machining
and/or the minimum possible
distortion during case-hardening.
Above all, we are also in a posi-
tion to supply these steel grades
in the form of bar stock with large
cross-sections and also in various
processed stages. For example:
disks sawn from bars, either with        Pre-machined to taste
or without a drilled hole. Our pro-      Make use of our wide-ranging
duction capabilities also include        capabilities and let us act as your
parts individually forged to shape.      extended workbench. Talk to our
The range of processing options          specialists. They can work with
goes all the way to bright surfaces      you in devising an individual solu-
with close tolerances.                   tion to meet your needs.




 14
                                                                                                               Steel portraits
• Carbodur 15 NiCr 13                          • Carbodur 17 Cr 3

NiCr-alloyed case-hardening steel for highly   Cr-alloyed case-hardening steel for compo-      • Carbodur 18 CrNiMo 7-6

stressed components in mechanical engi-        nents in mechanical and automotive engi-        CrNiMo-alloyed case-hardening steel for

neering with high demands on toughness         neering with low core strength, primarily for   heavy-duty and highly stressed transmis-

at low temperatures.                           wear stressed, e.g. piston pins and cam-        sion components in mechanical engineer-

                                               shafts                                          ing with high demands on toughness, e.g.

                                               • Carbodur 17 CrNi 6-6                          gear wheels, pinion gears and worm shafts

                                               CrNi-alloyed case-hardening steel for high-     • Carbodur 20 NiMoCrS 6-5

                                               ly stressed components in mechanical and        NiMoCr-alloyed case-hardening steel for

                                               automotive engineering with high strength       highly stressed components in mechanical



sliced?                                        and toughness at relatively large cross-

                                               sections, such as bevel pinions, pinion
                                                                                               and automotive engineering with high strength

                                                                                               and toughness, e.g. bevel pinions, pinion

                                               gears, shafts, pins and countershafts           gears, shafts, pins and countershafts

                                                                                               • Carbodur 20 MnCr 5

                                                                                               • Carbodur 20 MnCrS 5

                                                                                               CrMn-alloyed case-hardening steel for

                                                                                               components in mechanical and automotive

                                                                                               engineering with relatively high core strength,

                                                                                               e.g. gear wheels, ring gears, main shafts

                                                                                               and countershafts

                                                                                               • Carbodur 20 MoCr 4

                                                                                               • Carbodur 20 MoCrS 4

                                                                                               MoCr-alloyed case-hardening steels for

                                                                                               components in mechanical and automotive

                                                                                               engineering with relatively high core strength,

                                                                                               e.g. gear wheels, ring gears, main shafts

                                                                                               and countershafts

                                                                                               • Carbodur 20 NiCrMo 2-2

• Carbodur 16 MnCr 5                           • Carbodur 18 CrNi 8                            • Carbodur 20 NiCrMoS 2-2

• Carbodur 16 MnCrS 5                          CrNi-alloyed case-hardening steel for high-     NiCrMo-alloyed case-hardening steel for

CrMn-alloyed case-hardening steel for          ly stressed components in mechanical and        components in mechanical and automotive

components in mechanical and automotive        automotive engineering with very high           engineering with relatively high core strength,

engineering with relatively high core          strength and toughness at relatively large      e.g. gear wheels, spiders and ball cages

strength, e.g. relatively large piston pins,   cross-sections, such as bevel pinions, pin-     • Carbodur 22 CrMoS 3-5

camshafts and gear wheels                      ion gears, shafts, pins and countershafts       CrMo-alloyed case-hardening steel for

                                                                                               components in mechanical and automotive

                                                                                               engineering with relatively high core strength,

Carbodur –                               metallurgical                                         e.g. gear wheels, ring gears, shafts and

                                                                                               spiders

                     delicacies à la carte
                                                                                                                                          15
                                       We make our own
Our own steel production in our
modern steelworks in Witten is                  recipes
                                       able in Krefeld for the production
                                       of case-hardening steels involving
the basis for the purity and homo-     particularly stringent demands in
geneity of our case-hardening          terms of homogeneity, toughness
steels. Precisely defined proper-      and purity.
ties are achieved by means of
exact alloying and process             Electroslag remelting process                                          Remelting facilities

specifications for smelting, shap-     In the electroslag remelting pro-
                                                                                                             ESR
ing and heat treatment. The steels     cess (ESR), which works with al-
are smelted in a 130 t electric arc    ternating current, a cast or forged,                                    VAR

furnace.                               self-consuming electrode is im-
The metallurgical precision work       mersed in a bath of molten slag,
is performed in a downstream           which serves as an electrical resis-
ladle furnace of the same size.        tor.
                                                                                                             Ladle
Depending on the steel grade and       The material to be remelted drips                                    furnace

the dimensions of the end prod-        from the end of the electrode
uct, the steel melted in this way is   through the slag and forms the          Scrap       130-t-electric             Ladle degas-
                                                                                            arc furnace                sing station
cast in ingots or continuous cast      new ingot in a water-cooled                                                      (VD/VOD)
                                                                                Main production routes
blooms. Over 50 different mould        mould below. The heat dissipa-                  EDELSTAHL WITTEN-KREFELD GMBH

                                                                                       THYSSEN KRUPP STAHL AG
formats are available for ingot        tion leads to directional solidifica-
casting, ranging from 600 kg to        tion in the direction of the longitu-
160 t.                                 dinal ingot axis.
The continuous cast blooms are         The remelting slag fulfils several      new ingot. In addition, the slag
manufactured in two strands on a       functions in this process. On the       has a high capacity for absorbing
vertical continuous casting ma-        one hand, it develops the neces-        non-metallic inclusions, which
chine in a 475 x 340 mm format.        sary process heat, while at the         means that the remelted material
A remelting steelworks with two        same time supporting chemical           is free of coarse inclusions. The
electroslag remelting (ESR) fur-       reactions, such as desulphurisa-        improvement in the microscopic
naces and two vacuum arc re-           tion, and acting as an anti-            purity is attributable to desulphur-
melting (VAR) furnaces is avail-       oxidant for the melting bath of the     isation and the resultant high


 16
                                                                                                                                Steel production




 steel, using reliable
 and the best ingredients

                     Blooming-slabbing mill


ot casting



                                                                                                   Products
                                                                                                  • As-cast ingots
                                  Long forging                     Machining                        As-continuously cast
                                   machines                                       Finishing         bloom material
                                                                                  departments,
                                                                                  forging shops   • Open-die forgings
                                                                                                    as-forged or machined

                                                                                                  • Forged semis
                                                        Heat          As-forged
                                       LSX 55
                         33 MN press                 treatment            Peeling                 • Forged round billets
                                                      facilities         machines                   for tubemaking
                                                                                                    as-forged or peeled
                                                                                  Finishing
                                       LSX 25                                     departments,    • Forged bar steel
                                                                                  rolling mills     as-forged or machined

                                                                                                  • Machined tool steel
                                                                      As-rolled                     forged or rolled

                                                                                                  • Rolled semis

ontinuous bloom                                                                                   • Rolled tube rounds
                                                                                                    as-rolled or peeled
 er, 475 x 340 mm,
    2 strands                                                  Untreated                          • Rolled bar steel
                                                                                                    as-rolled or machined
                              Blooming/billet/large-size                                          • Universal plate and flats
                                   bar rolling mill
                                                                                                  • Special products




       degree of sulphidic purity, and
       also to a reduction in the size and
       quantity of oxidic inclusions.
                                                                         Carbodur –                                  technological

                                                                                                  precision from the start



                                                                                                                                               17
                                                              Carbodur
                                                        tailored to suit
Vacuum arc remelting process          lowest possible sulphur content
The vacuum arc remelting (VAR)        has to be set prior to remelting, in
process works with cast or            order also to meet the most strin-
forged, self-consuming elec-          gent demands on the degree of
trodes in a vacuum.                   sulphidic purity. Moreover, this
Using an electric arc in a vacuum,    process guarantees the lowest
a melting bath is generated in a      possible quantities of dissolved
copper crucible, which acts as        gases in the steel and a minimum
the opposite pole to the remelting    of segregation.
electrode and is connected to a
DC voltage source via current         Steel processing
contacts.                             The blooming mill in Witten pro-
A new ingot is formed from the        duces semi-finished products,
liquefied electrode material drop     steel bars and wide flats. Two
by drop in a continuous process.      modern finishing lines for check-
In the VAR process, refinement of     ing the inner and outer surface
the steel is brought about by the     condition, as well as the dimen-
reaction of the oxygen dissolved      sions and identity, are available
in the steel with the carbon in the   for rolled and forged products
molten material under the effect      and steel bars. The forge is
of the vacuum. This results in the    equipped with a 33 MN press, a
best possible degree of micro-        GFM LSX 55 horizontal long forg-
scopic oxidic purity and freedom      ing machine and a GFM LSX 25
from macroscopic inclusions. As       long forging machine.
no desulphurisation takes place
during this remelting process, the


 18
                              Steel processing




– Steels precisely
your applications




            We   work ahead
                       for your   benefit


                                             19
  CARBODUR® C 15 E / C 15 R
        Material No.
        Code
                                              Material No.          Designation                         Material No.           Designation

                                                1.1141                       C15E                         1.1140                   C15R


        Chemical
        composition                                                 C                Si             Mn                P            S

  Typical analysis in %                              C 15 E 0.12 – 0.18             ≤0.40      0.30 – 0.60         ≤0.035        ≤0.035
                                                     C 15 R 0.12 – 0.18             ≤0.40      0.30 – 0.60         ≤0.035      0.020–0.040




        Hardness in various
        treatment conditions
                                                    Treated for                       Treated                      Soft-annealed A           Annealed to spherical     Treated for ferrite-
                                                    shearing S                    for strength TH                                                carbides AC          pearlite structure FP
                                                        HB                               HB                               HB                         HB                        HB

                                                        1)                                                            max. 143                     max. 135


        Heat treatments
                                                Type of treatment                      Treatment temperature                                               Cooling

                                                 Case-hardening                               880 – 980 °C                                           Water (oil),
                                                  Carburising 2)                                                                   Hot bath 160 – 250 °C, case-hardening box, air      4)


                                               Direct hardening         3)
                                                                                              880   –   980   °C                             Water (oil), hot bath 160 – 250 °C   4)


                                                  Core refining                               880   –   920   °C                             Water (oil), hot bath 160 – 250 °C   4)


                                                 Case refining                                780   –   820   °C                             Water (oil), hot bath 160 – 250 °C   4)


  See flap for footnotes                   Tempering (stress-relieving) 5)                    150   –   200   °C                                               Air



           Hardenability in the                              Distance from the quenched end in mm
           end-quench test
                                                               1             2            3         4         5           6        7          8
  Hardness in HRC
                                                 H
                                                max.           45            42       35         33           32          28      26          24
                                                min.           39            35       31         27           25          22      20           –




           Hardenability diagram


                 55

                 50

                 45

                 40
  Härte in HRC
Hardnessin HRC




                 35

                 30

                 25

                 20

                 15
                      0   5   10    15   20    25     30      35    40        45
                 Abstand von der abgeschreckten Stirnfläche in mm
                                   Distance from quenched end in mm

                 20
                                                                                                                                          CARBODUR® 15 NiCr 13
        Material No.
        Code
                                                Material No.               Designation

                                                  1.5752                    15NiCr13


        Chemical
        composition
                                                   C               Si                Mn           P                                      S                    Cr                 Ni

  Typical analysis in %                        0.14– 0.20       ≤ 0.40          0.40 – 0.70     ≤0.035                            ≤0.035               0.60 – 0.90 3.60– 3.50




        Hardness in various
        treatment conditions
                                                      Treated for                         Treated                                       Soft-annealed A                        Annealed to spherical                                  Treated for ferrite-
                                                      shearing S                     for strength TH*                                                                              carbides AC                                      pearlite structure FP**
 * For diameters up to 150 mm                             HB                                HB                                                       HB                                HB                                                      HB
 ** For diameters up to 60 mm
                                                       max. 255                           179 – 229                                             max. 229                                     max. 180                                          166 – 217


        Heat treatments
                                                   Type of treatment                       Treatment temperature                                                                                         Cooling

                                                 Case-hardening                                 880 – 980 °C                                                            Oil (water), hot bath 160 – 250 °C,
                                                   Carburising 2)                                                                                               Salt bath (580 – 650 °C), case-hardening box, air                                               4)


                                                Direct hardening 3)                             880   –    980                   °C                                                  Oil, hot bath 160 – 250 °C                                4)


                                                   Core refining                                840   –    880                   °C                                                  Oil, hot bath 160 – 250 °C                                4)


                                                  Case refining                                 780   –    820                   °C                                                  Oil, hot bath 160 – 250 °C                                4)


 See flap for footnotes                     Tempering (stress-relieving) 5)                     150   –    200                   °C                                                                Air



           Hardenability in the                                Distance from the quenched end in mm
           end-quench test
                                                                  1.5            3          5         7                            9              11               13           15                20                25                30              35        40
 Hardness in HRC
                                                   H
                                                  max.             48           48         48         47                          45              44               42           41                38                35                34              34        33
                                                  min.             41           41         41         40                          38              36               33           30                24                22                22              21        21

                                                  HH
                                                  max.             48           48         48         47                          45              44               42           41                38                35                34              34        33
                                                  min.             43           43         43         42                          40              39               36           34                29                26                26              25        25

                                                   HL
                                                  max.             46           46         46         45                          43              41               38           37                33                31                30              30        29
                                                  min.             41           41         41         40                          38              36               33           30                24                22                22              21        21

           Hardenability diagram                                                                                         Time-temperature-transformation diagram
                                                                                                                         for continuous cooling

                  55                                                                                                            1200

                                                                                                                                1100
                  50                                                                                                            1000
                                                          HH-Sorte
                                                          HH grade
                                                          Überschneidung
                                                           Overlap of                                                           900
                  45                                      HH+HL-Sorte
                                                          HH + HL grade                                                                                                                                                                                 AC3
                                                          HL-Sorte
                                                          HL grade                                                              800
                                                                                                           Temperature in o°C
                                                                                                            Temperatur in C




                                                                                                                                                                                                                                                        AC1
                  40                                                                                                            700
                                                                                                                                           A                                                                                          75 75
                                                                                                                                                                                                             75
                                                                                                                                                                                                                F              75       15 25
                                                                                                                                600                                                               70
Hardness in HRC




                                                                                                                                                                                     5
 Härte in HRC




                  35                                                                                                                                                                         45                                      P
                                                                                                                                500
                                                                                                                                                                                         B
                                                                                                                                        Ms
                                                                                                                                400                                 30
                  30                                                                                                                                                      50    90 95
                                                                                                                                                                                      90          50          20         15
                                                                                                                                300                                                                                                      15
                                                                                                                                         M
                  25                                                                                                            200
                                                                                                                                                                                                                                                8

                                                                                                                                          Hardness
                                                                                                                                          Härtewerte values
                                                                                                                                100
                  20                                                                                                                           HV 10               360 352 328 313 282 277 261 245                    231       228      227        192 169
                                                                                                                                  0
                                                                                                                                       100                101                  102                     103                      104                   105                 106
                  15                                                                                                                   Time s
                                                                                                                                       Zeit inin s
                       0   5   10    15   20     25     30      35         40    45                                                                                      100                   101                       102                    103                 104
                                                                                                                                                                         Zeit in min
                                                                                                                                                                         Time in min
                  Abstand von der abgeschreckten Stirnfläche in mm
                                    Distance from quenched end in mm                                                                                                                                               100                        101             102
                                                                                                                                                                                                                    Time h
                                                                                                                                                                                                                    Zeit inin h
                                                                                                                                                                                                                                                              21
CARBODUR® 16 MnCr 5 / 16 MnCrS 5
        Material No.
        Code
                                               Material No.               Designation                         Material No.                                      Designation

                                                 1.7131                       16MnCr5                                              1.7139                        16MnCrS5


        Chemical
        composition
                                                                          C                Si             Mn                                     P                        S                             Cr
 Typical analysis in %
                                                16 MnCr 5 0.14– 0.19                     ≤0.40      1.10 – 1.30                             ≤0.035            ≤0.035    0.80 – 1.10
                                               16 MnCrS 5 0.14– 0.19                     ≤0.40      1.10 – 1.30                             ≤0.035          0.020–0.040 0.80 – 1.10



        Hardness in various
        treatment conditions
                                                     Treated for                             Treated                                       Soft-annealed A                               Annealed to spherical                                     Treated for ferrite-
                                                     shearing S                         for strength TH*                                                                                     carbides AC                                         pearlite structure FP**
* For diameters up to 150 mm                             HB                                    HB                                                      HB                                        HB                                                         HB
** For diameters up to 60 mm
                                                          1)                               156 – 207                                                 max. 207                                            max. 165                                          140 – 187


        Heat treatments
                                                 Type of treatment                           Treatment temperature                                                                                                          Cooling

                                                  Case-hardening                                    880 – 980 °C                                                              Oil (water), hot bath 160 – 250 °C,
                                                   Carburising 2)                                                                                                     Salt bath (580 – 680 °C), case-hardening box, air                                                          4)


                                                Direct hardening              3)
                                                                                                    880   –   980                    °C                                       Oil (water), hot bath 160 – 250 °C 4)
                                                   Core refining                                    860   –   900                    °C                                       Oil (water), hot bath 160 – 250 °C 4)
                                                  Case refining                                     780   –   820                    °C                                       Oil (water), hot bath 160 – 250 °C 4)
See flap for footnotes                      Tempering (stress-relieving) 5)                         150   –   200                    °C                                                         Air



           Hardenability in the                                Distance from the quenched end in mm
           end-quench test
                                                                 1.5               3            5         7                           9               11              13                      15                20                     25             30           35                40
Hardness in HRC
                                                  H
                                                 max.             47               46        44        41                             39              37              35                      33                31                     30             29           28                27
                                                 min.             39               36        31        28                             24              21               –                       –                 –                      –              –            –                 –

                                                 HH
                                                 max.             47               46        44        41                             39              37              35                      33                31                     30             29           28                27
                                                 min.             42               39        35        32                             29              26              24                      22                20                      –              –            –                 –

                                                  HL
                                                 max.             44               43        40        37                             34              32              30                      28                26                     25             24           23                22
                                                 min.             39               36        31        28                             24              21               –                       –                 –                      –              –            –                 –

           Hardenability diagram                                                                                              Time-temperature-transformation diagram
                                                                                                                              for continuous cooling

                  55                                                                                                               1200

                                                                                                                                   1100
                  50
                                                                                                                                   1000
                                                         HH-Sorte
                                                         HH grade
                                                         Überschneidung
                                                         Overlap of                                                                900
                  45                                     HH+HL-Sorte
                                                         HH + HL grade                                                                                                                                                                                                   AC3
                                                         HL-Sorte
                                                         HL grade                                                                  800
                                                                                                                Temperatur in °C
                                                                                                              Temperature in oC




                  40                                                                                                               700                                    F                                           60         65                                      AC1
                                                                                                                                                                                    20       30 40 50 50 60
                                                                                                                                                                      3 10 15                                                      35
                                                                                                                                                                                         3     P                            40
                                                                                                                                   600
Hardness in HRC
 Härte in HRC




                                                                                                                                                                                                   5
                  35                                                                                                                             A                    B                                 10 20
                                                                                                                                                                                                                35
                                                                                                                                   500                                                                                37
                                                                                                                                                MS         97         100
                  30                                                                                                               400                                         81 80
                                                                                                                                                                                              85   77
                                                                                                                                                 M                                                       65
                                                                                                                                                                                                                50
                                                                                                                                   300                                                                               30
                                                                                                                                                                                                                           15
                  25                                                                                                                                                                                                             93
                                                                                                                                   200
                                                                                                                                            Hardness
                                                                                                                                            Härtewerte values
                                                                                                                                   100                            394         317    278 251 243 221 207 199 187                       182 170 156
                  20                                                                                                                            HV 10                                                                            188
                                                                                                                                     0
                                                                                                                                          100                   101                          102                      103                       104                105                     106
                  15                                                                                                                      Zeit in s
                                                                                                                                          Time in s
                       0   5   10    15   20    25     30       35        40       45                                                                                           100                             101                       102                103                     104

                  Abstand von der abgeschreckten Stirnfläche in mm
                                    Distance from quenched end in mm
                                                                                                                                                                               Zeit
                                                                                                                                                                               Timein min
                                                                                                                                                                                     in min
                                                                                                                                                                                                                                      100                  101                 102
                                                                                                                                                                                                                                      Zeit in h
                                                                                                                                                                                                                                      Time in h
                  22
                                                                                                                                                         CARBODUR® 17 Cr 3
        Material No.
        Code
                                               Material No.               Designation

                                                  1.7016                      17Cr3


        Chemical
        composition
                                                  C                Si              Mn          P                                   S                          Cr
  Typical analysis in %
                                              0.14– 0.20          ≤0.40       0.60 – 0.90    ≤0.035                           ≤0.035               0.70 – 1.00




        Hardness in various
        treatment conditions
                                                     Treated for                        Treated                                    Soft-annealed A                               Annealed to spherical                       Treated for ferrite-
                                                     shearing S                     for strength TH                                                                                  carbides AC                            pearlite structure FP
                                                         HB                                HB                                                  HB                                        HB                                          HB

                                                            1)                                                                               max. 174                                            max. 155


        Heat treatments
                                                  Type of treatment                     Treatment temperature                                                                                             Cooling

                                                Case-hardening                               880 – 980 °C                                                                           Wasser (Öl),
                                                  Carburising 2)                                                                                                   Hot bath 160 – 250 °C, case-hardening box, air                                    4)


                                               Direct hardening 3)                           880   –   980                   °C                                                  Water (oil), hot bath 160 – 250 °C                     4)


                                                  Core refining                              860   –   900                   °C                                                  Water (oil), hot bath 160 – 250 °C                     4)


                                                 Case refining                               780   –   820                   °C                                                  Water (oil), hot bath 160 – 250 °C                     4)


 See flap for footnotes                    Tempering (stress-relieving) 5)                   150   –   200                   °C                                                                    Air



           Hardenability in the                                  Distance from the quenched end in mm
           end-quench test
                                                                   1.5         3        5          7                           9              11                   13             15               20         25
 Hardness in HRC
                                                  H
                                                 max.              47         44        40      33                            29              27                   25             24               23         21
                                                 min.              39         35        25      20                             –               –                    –              –                –          –

                                                 HH
                                                 max.              47         44        40      33                            29              27                   25             24               23         21
                                                 min.              42         38        30      24                            20               –                    –              –                –          –

                                                  HL
                                                 max.              44         41        35      29                            25              23                   21             20               –           –
                                                 min.              39         35        25      20                             –               –                    –              –               –           –

           Hardenability diagram                                                                                     Time-temperature-transformation diagram
                                                                                                                     for continuous cooling

                 55                                                                                                         1200

                                                                                                                            1100
                 50
                                                                                                                            1000
                                                        HH-Sorte
                                                        HH grade
                                                        Überschneidung
                                                         Overlap of                                                         900
                 45                                     HH+HL-Sorte
                                                         HH + HL grade
                                                                                                                                                                                                                                              AC3
                                                                                                                                         A
                                                        HL-Sorte
                                                        HL grade                                                            800
                                                                                                       Temperature in o°C




                                                                                                                                                                                                                                              AC1
                                                                                                        Temperatur in C




                 40                                                                                                         700                                 70 75 72
                                                                                                                                                                                     75
                                                                                                                                               F         30 67       20 25
                                                                                                                                                                                      25
                                                                                                                                                5              P  15
                                                                                                                                         1                    1 3
                                                                                                                            600
  Härte in HRC
Hardnessin HRC




                 35                                                                                                          MS                          B
                                                                                                                                        15    35
                                                                                                                            500                          85      65 20
                                                                                                                                                                       15    5   3
                                                                                                                                   M
                 30                                                                                                         400

                                                                                                                            300
                 25
                                                                                                                            200        446
                                                                                                                                   Hardness
                                                                                                                                   Härtewerte
                                                                                                                            100    values          439                           181
                 20                                                                                                                   HV 10
                                                                                                                                                          368      297 236 206         160 151      141

                                                                                                                              0
                                                                                                                               100                           101                 102                    103              104            105                     106
                 15                                                                                                             Time s
                                                                                                                                Zeit inin s
                      0   5   10    15   20     25     30         35     40    45                                                                                        100                      101              102            103                     104
                                                                                                                                                                         Zeit in min
                                                                                                                                                                         Time in min
                 Abstand von der abgeschreckten Stirnfläche in mm
                                   Distance from quenched end in mm                                                                                                                                           100               101                 102
                                                                                                                                                                                                              Time h
                                                                                                                                                                                                              Zeit inin h
                                                                                                                                                                                                                                                    23
    CARBODUR® 17 CrNi 6-6
            Material No.
            Code
                                                Material No.              Designation

                                                   1.5918                  17CrNi6-6


            Chemical
            composition
                                                   C              Si                Mn           P                                      S                   Cr                            Ni
     Typical analysis in %
                                               0.14– 0.20       ≤0.40          0.50 – 0.90     ≤0.035                            ≤0.035             1.40 – 1.70 1.40 – 1.70




            Hardness in various
            treatment conditions                      Treated for                         Treated                                       Soft-annealed A                                 Annealed to spherical                                     Treated for ferrite-
                                                      shearing S                     for strength TH*                                                                                       carbides AC                                         pearlite structure FP**
    * For diameters up to 150 mm                          HB                                HB                                                     HB                                           HB                                                         HB
    ** For diameters up to 60 mm
                                                       max. 255                          175 – 229                                            max. 229                                                max. 178                                               156– 207


            Heat treatments
                                                   Type of treatment                      Treatment temperature                                                                                                        Cooling

                                                   Case-hardening                              880 – 980 °C                                                               Oil (water), hot bath 160 – 250 °C,
                                                    Carburising 2)                                                                                                Salt bath (580 – 650 °C), case-hardening box, air                                                             4)


                                               Intermediate annealing                          630   –    650                    °C                                                                  Air, furnace
                                                    Core refining                              830   –    870                    °C                                                     Oil (water), hot bath 160 – 250 °C                                         4)


                                                    Case refining                              780   –    820                    °C                                                     Oil (water), hot bath 160 – 250 °C                                         4)


    See flap for footnotes                   Tempering (stress-relieving) 5)                   150   –    200                    °C                                                                        Air



              Hardenability in the                            Distance from the quenched end in mm
              end-quench test
                                                                  1.5           3          5         7                            9                11              13                    15               20                     25                   30           35           40
    Hardness in HRC
                                                   H
                                                  max.            47           47         46         45                           43               42              41                    39               37                     35                   34           34           33
                                                  min.            39           38         36         35                           32               30              28                    26               24                     22                   21           20           20

                                                  HH
                                                  max.            47           47         46         45                           43               42              41                    39               37                     35                   34           34           33
                                                  min.            42           41         39         38                           36               34              32                    30               28                     26                   25           25           24

                                                   HL
                                                  max.            44           44         43         42                           39               38              37                    35               33                     31                   30           29           29
                                                  min.            39           38         36         35                           32               30              28                    26               24                     22                   21           20           20

              Hardenability diagram                                                                                       Time-temperature-transformation diagram
                                                                                                                          for continuous cooling

                  55                                                                                                           1200

                                                                                                                               1100
                  50                                                                                                           1000
                                                         HH-Sorte
                                                         HH grade
                                                         Überschneidung
                                                         Overlap of                                                            900
                  45                                     HH+HL-Sorte
                                                          HH + HL grade                                                                                                                                                                                                 AC3
                                                         HL-Sorte
                                                         HL grade                                                              800
                                                                                                          Temperature in o°C




                                                                                                                                                                                                                                                                        AC1
                                                                                                            Temperatur in C




                  40                                                                                                           700                                                                                                     70 75
                                                                                                                                                                                                  F                        60 65
                                                                                                                                                                                                                    40 55                  25
                                                                                                                                                                                                  15      30            10 35
                                                                                                                               600                                                                                                    35 30
Hardness in HRC




                                                                                                                                                                                    3      5 10
 Härte in HRC




                  35                                                                                                                    A                                                                                   P
                                                                                                                               500
                                                                                                                                        MS              100
                                                                                                                                                                  100                                                 B
                                                                                                                                                                               100
                  30                                                                                                           400                          100                         100 97
                                                                                                                                                                        100                        95    90 85
                                                                                                                                        M                                                                             70
                                                                                                                               300                                                                                               60 35
                                                                                                                                                                                                                                            5
                  25                                                                                                           200
                                                                                                                                        Hardness
                                                                                                                                        Härtewerte values
                                                                                                                               100                                409         357         297           270         262         222      175 157       154
                  20                                                                                                                         HV 10                      394          318          276         266         242          203 161 154
                                                                                                                                 0
                                                                                                                                      100                101                            102                     103                             104                105                    106
                  15                                                                                                                  Zeit in
                                                                                                                                      Timein s s
                       0   5   10    15   20     25     30     35         40    45                                                                                            100                         101                         102                    103                    104
                                                                                                                                                                               Zeit in min
                                                                                                                                                                              Timein min
                  Abstand von der abgeschreckten Stirnfläche in mm
                                    Distance from quenched end in mm                                                                                                                                                             100                       101                102
                                                                                                                                                                                                                                 Zeit in
                                                                                                                                                                                                                                 Timein hh
                  24
                                                                                                                                                CARBODUR® 18 CrNi 8
          Material No.
          Code
                                                  Material No.             Designation

                                                        1.5920              18CrNi8


          Chemical
          composition
                                                        C             Si             Mn           P                                     S                   Cr                     Ni

   Typical analysis in %                         0.15– 0.20 0.15–0.40 0.40 – 0.60               ≤0.035                             ≤0.035         1.80 – 2.10 1.80 – 2.10




          Hardness in various
          treatment conditions                              Treated for                   Treated                                       Soft-annealed A                    Annealed to spherical                                    Treated for ferrite-
                                                            shearing S               for strength TH*                                                                          carbides AC                                        pearlite structure FP**
   * For diameters up to 150 mm                                 HB                          HB                                                    HB                               HB                                                        HB
   ** For diameters up to 60 mm
                                                             max. 255                     199 – 229                                             max. 225                                      max. 180                                        158– 205


          Heat treatments
                                                        Type of treatment                  Treatment temperature                                                                                               Cooling

                                                     Case-hardening                             900 – 950                          °C                                    Oil (water), hot bath 160 – 250 °C,
                                                       Carburising 2)                           630 – 650                          °C                            Salt bath (580 – 650 °C), case-hardening box, air                                                4)


                                                    Direct hardening 3)                         840 – 870                          °C                                                   Air, furnace
                                                       Core refining                            800 – 830                          °C                                      Oil (water), hot bath 160 – 250 °C                                         4)


                                                      Case refining                             170 – 210                          °C                                      Oil (water), hot bath 160 – 250 °C                                         4)


   See flap for footnotes                       Tempering (stress-relieving) 5)                                                                                                               Air



             Hardenability in the                                   Distance from the quenched end in mm
             end-quench test
                                                                     1.5        3           5         7                            9             11              13            15                   20               25             30                35           40
   Hardness in HRC
                                                         H
                                                        max.          49        49         49         49                           49            49              49            49                   48               47             47                46           46
                                                        min.          41        41         40         39                           39            38              37            36                   35               35             34                34           33

                                                        HH
                                                        max.          49        49         49         49                           49            49              49            49                   48               47             47                46           46
                                                        min.          44        44         43         42                           42            42              41            40                   39               39             38                38           37

                                                         HL
                                                        max.          46        46         46         46                           46            45              45            45                   44               43             43                42           42
                                                        min.          41        41         40         39                           39            38              37            36                   35               35             34                34           33

             Hardenability diagram                                                                                           Time-temperature-transformation diagram
                                                                                                                             for continuous cooling

                  55                                                                                                        1200

                                                                                                                            1100
                  50
                                                                                                                            1000

                                                                                                                            900
                  45
                                                                                                                                                                                                                                                                 AC3
                                                                                                                            800
                                                                                                       Temperature in o°C




                                                                                                                                                                                                                                                                 AC1
                                                                                                         Temperatur in C




                  40                                                                                                        700
                                                                                                                                                                                                                        30
                                                                                                                                                                                                           F    10    30 5   P
                                                                                                                            600
Hardness in HRC




                                                                                                                                                                                                       5
 Härte in HRC




                  35                                                                                                                        A
                                                                                                                            500
                                                                                                                                   MS                                          B
                  30                                                                                                        400                                                         100    100   100 100 95
                                                                                                                                         M                                                                            90
                                      HH-Sorte
                                      HH grade                                                                              300
                                                                                                                                                                                                                             70    65

                                      Überschneidung
                                      Overlap of
                  25                  HH+HL-Sorte
                                      HH + HL grade                                                                         200
                                      HL-Sorte
                                      HL grade                                                                                      Hardness
                                                                                                                                    Härtewerte values
                                                                                                                            100                         429      425 417   425      390       363    342 333 312 312 312 268 249
                  20                                                                                                                   HV 10
                                                                                                                              0
                                                                                                                               100                    101                102                     103                       104                  105                    106
                  15                                                                                                            Zeit in s
                                                                                                                                Time in s
                       0   5   10    15     20         25     30    35     40   45                                                                                 100                        101                    102                  103                    104
                                                                                                                                                                   Zeit in min
                                                                                                                                                                   Time in min
                  Abstand von der abgeschreckten Stirnfläche in mm
                                    Distance from quenched end in mm                                                                                                                                            100                     101                102
                                                                                                                                                                                                                Zeit in h
                                                                                                                                                                                                                Time in h
                                                                                                                                                                                                                                                                 25
  CARBODUR® 18 CrNiMo 7-6
         Material No.
         Code
                                                 Material No.              Designation

                                                       1.6587             18CrNiMo7-6


         Chemical
         composition
                                                      C             Si                Mn           P                                     S                     Cr                        Ni                            Mo

   Typical analysis in %                      0.15– 0.21           ≤0.40        0.50 – 0.90      ≤0.035                            ≤0.035            1.50 – 1.80 1.40 – 1.70 0.25 – 0.35




         Hardness in various
         treatment conditions                              Treated for                     Treated                                        Soft-annealed A                              Annealed to spherical                                              Treated for ferrite-
                                                           shearing S                 for strength TH*                                                                                     carbides AC                                                  pearlite structure FP**
  * For diameters up to 150 mm                                 HB                            HB                                                      HB                                        HB                                                                  HB
  ** For diameters up to 60 mm
                                                            max. 255                       179 – 229                                           max. 229                                                max. 180                                                        159– 207


         Heat treatments
                                                       Type of treatment                    Treatment temperature                                                                                                           Cooling

                                                       Case-hardening                            880 – 980 °C                                                                Oil (water), hot bath 160 – 250 °C,
                                                        Carburising 2)                                                                                               Salt bath (580 – 650 °C), case-hardening box, air                                                                4)


                                                Intermediate annealing                           630   –    650                    °C                                                               Air, furnace
                                                     Core refining                               830   –    870                    °C                                                  Oil (water), hot bath 160 – 250 °C                                                     4)


                                                     Case refining                               780   –    820                    °C                                                  Oil (water), hot bath 160 – 250 °C                                                     4)


  See flap for footnotes                      Tempering (stress-relieving) 5)                    150   –    200                    °C                                                                     Air



           Hardenability in the                                   Distance from the quenched end in mm
           end-quench test
                                                                    1.5          3           5         7                            9                11               13                15                     20                     25                     30               35          40
  Hardness in HRC
                                                       H
                                                      max.           48          48         48         48                           47               47               46                46                     44                     43                     42               41          41
                                                      min.           40          40         39         38                           37               36               35                34                     32                     31                     30               29          29

                                                      HH
                                                      max.           48          48         48         48                           47               47               46                46                     44                     43                     42               41          41
                                                      min.           43          43         42         41                           40               40               39                38                     36                     35                     34               33          33

                                                       HL
                                                      max.           45          45         45         45                           44               43               42                42                     40                     39                     38               37          37
                                                      min.           40          40         39         38                           37               36               35                34                     32                     31                     30               29          29

           Hardenability diagram                                                                                            Time-temperature-transformation diagram
                                                                                                                            for continuous cooling

                 55                                                                                                              1200

                                                                                                                                 1100
                 50
                                                                                                                                 1000

                                                                                                                                 900
                 45                                                                                                                                                                                                                                                                 AC3
                                                                                                                                 800                                                                                                                                                AC1
                                                                                                            Temperature in o°C
                                                                                                              Temperatur in C




                 40                                                                                                              700                                                                                                   55             65
                                                                                                                                                                                                   3       5
                                                                                                                                                                                                               F       20
                                                                                                                                                                                                                                 45
                                                                                                                                                                                                                                                       30
                                                                                                                                 600                                                                                                        30
                                                                                                                                                                                                                                                 P
  Härte in HRC
Hardnessin HRC




                 35                                                                                                                       A
                                                                                                                                 500
                                                                                                                                                                                                       B
                 30                                                                                                              400 MS                   60
                                                                                                                                                                     80 90 100
                                                                                                                                                                               100 100 100
                                                                                                                                                                                           100
                                     HH-Sorte
                                     HH grade                                                                                    300                                                                               97       95         80        55     15
                                     Überschneidung                                                                                       M                                                                                                                       5
                 25                  Overlap of
                                     HH+HL-Sorte
                                                                                                                                 200
                                     HH + HL grade
                                     HL-Sorte
                                     HL grade                                                                                             Hardness
                                                                                                                                          Härtewerte values
                                                                                                                                 100                                       425         383         343           327                        261             215   175
                 20                                                                                                                           HV 10                  426         418         360           336
                                                                                                                                                                                                                            314       286         242

                                                                                                                                   0
                                                                                                                                        100                    101                     102                         103                                104                     105               106
                 15                                                                                                                     Zeit in
                                                                                                                                        Timein s s
                      0   5   10    15     20         25     30    35      40     45                                                                                         100                            101                             102                         103               104
                                                                                                                                                                              Zeit in min
                                                                                                                                                                             Timein min
                 Abstand von der abgeschreckten Stirnfläche in mm
                                   Distance from quenched end in mm                                                                                                                                                                   100                             101           102
                                                                                                                                                                                                                                      Zeit in
                                                                                                                                                                                                                                      Timein h h
                 26
                                                                                              CARBODUR® 20 NiMoCrS 6-5
          Material No.
          Code
                                               Material No.          Designation

                                                 1.6757             20NiMoCrS6-5


          Chemical
          composition
                                                  C            Si                  Mn           P                                      S                 Cr                  Ni                         Mo
   Typical analysis in %
                                              0.18– 0.28 max. 0.40 0.50 – 0.70                ≤0.035                          0.020–0.040 0.65 – 0.85 1.50 – 1.90 0.25–0.40




          Hardness in various
          treatment conditions                       Treated for                        Treated                                        Soft-annealed A                     Annealed to spherical                                    Treated for ferrite-
                                                     shearing S                    for strength TH*                                                                            carbides AC                                        pearlite structure FP**
   * For diameters up to 150 mm                          HB                               HB                                                      HB                               HB                                                        HB
   ** For diameters up to 60 mm
                                                      max. 255                          170 – 220                                            max. 220                                     max. 180                                             155 – 205


          Heat treatments
                                                 Type of treatment                       Treatment temperature                                                                                              Cooling

                                                     Case-hardening                           900 – 950 °C                                                            Oil (water), hot bath 160 – 250 °C,
                                                      Carburising 2)                                                                                          Salt bath (580 – 650 °C), case-hardening box, air                                                 4)


                                                Direct hardening       3)
                                                                                              870   –    900                    °C                                               Oil, hot bath 160 – 250 °C                                    4)


                                                   Core refining                              840   –    870                    °C                                               Oil, hot bath 160 – 250 °C                                    4)


                                                  Case refining                               800   –    830                    °C                                               Oil, hot bath 160 – 250 °C                                    4)


   See flap for footnotes                   Tempering (stress-relieving) 5)                   170   –    210                    °C                                                             Air



            Hardenability in the                            Distance from the quenched end in mm
            end-quench test
                                                               1.5             3          5         7                            9                11          13            15                    20             25                 30                35            40
   Hardness in HRC
                                                  H
                                                 max.          49           49           48         47                           46               45          44            44                    42             41                 39                38            38
                                                 min.          39           39           38         37                           36               35          33            32                    30             28                 26                25            23

                                                 HH
                                                 max.          49           49           48         47                           46               45          44            44                    42             41                 39                38            38
                                                 min.          42           42           41         40                           39               38          37            36                    34             32                 30                29            28

                                                  HL
                                                 max.          46           46           45         44                           43               42          40            40                    38             37                 35                34            33
                                                 min.          39           39           38         37                           36               35          33            32                    30             28                 26                25            23

            Hardenability diagram                                                                                        Time-temperature-transformation diagram
                                                                                                                         for continuous cooling

                 55                                                                                                           1200
                                                              HH-Sorte
                                                              HH grade                                                        1100
                                                              Überschneidung
                                                              Overlap of
                 50                                           HH+HL-Sorte
                                                               HH + HL grade                                                  1000
                                                              HL-Sorte
                                                              HL grade
                                                                                                                              900
                 45
                                                                                                                                                                                                                                                        AC3
                                                                                                                              800
                                                                                                           Temperatur in °C




                                                                                                                                                                                                                                                        AC1
                                                                                                         Temperature in oC




                 40                                                                                                           700
                                                                                                                                             A                                       3
                                                                                                                                                                                              5        15 43            48         50    -F
                                                                                                                                                                                                         10 30           35             50-P
                                                                                                                              600                                                         3        3
  Härte in HRC
Hardnessin HRC




                 35
                                                                                                                              500
                                                                                                                                                                                 B
                                                                                                                                       MS
                 30                                                                                                           400                             5
                                                                                                                                                                   20 80
                                                                                                                                                                           85 85     85
                                                                                                                              300                                                             90       89
                                                                                                                                                                                                              87
                 25                                                                                                                         M                                                                                25
                                                                                                                              200                                                                                                       15
                                                                                                                                                                                                                   72
                                                                                                                                       Hardness
                                                                                                                                       values
                                                                                                                                       Härtewerte 468
                                                                                                                              100
                 20                                                                                                                         HV 10
                                                                                                                                                        468    468 442 421 383 297 297 285 274 254                 236       221 206 181        160

                                                                                                                                0
                                                                                                                                     100                101                102                         103                        104                 105                 106
                 15                                                                                                                  Zeit in
                                                                                                                                     Timein s s
                      0   5   10    15   20     25     30     35     40        45                                                                                   100                       101                    102                        103                 104
                                                                                                                                                                    Zeit in min
                                                                                                                                                                    Timein min
                 Abstand von der abgeschreckten Stirnfläche in mm
                                   Distance from quenched end in mm                                                                                                                                              100                         101              102
                                                                                                                                                                                                                 Zeit in
                                                                                                                                                                                                                 Timein h h
                                                                                                                                                                                                                                                               27
CARBODUR® 20 MnCr 5 / 20 MnCrS 5
        Material No.
        Code                                  Material No.               Designation                         Material No.                                   Designation

                                                1.7147                       20MnCr5                                              1.7149                     20MnCrS5


        Chemical
        composition                                                      C                Si             Mn                                  P                      S                           Cr
 Typical analysis in %
                                               20 MnCr 5 0.17– 0.22                     ≤0.40      1.10 – 1. 40                          ≤0.035            ≤0.035 1.00 – 1.30
                                              20 MnCrS 5 0.17– 0.22                     ≤0.40      1.10 – 1.40                           ≤0.035          0.020–0.040 1.00 – 1.30




        Hardness in various
        treatment conditions
                                                    Treated for                             Treated                                      Soft-annealed A                          Annealed to spherical                                   Treated for ferrite-
                                                    shearing S                         for strength TH*                                                                               carbides AC                                       pearlite structure FP**
* For diameters up to 150 mm                            HB                                    HB                                                  HB                                      HB                                                       HB
** For diameters up to 60 mm
                                                        1)                                170 – 217                                          max. 217                                                 max. 180                                    152 – 201


        Heat treatments
                                                Type of treatment                           Treatment temperature                                                                                                      Cooling

                                                 Case-hardening                                    880 – 980 °C                                                                   Oil (water), hot bath 160 – 250 °C,                                     4)


                                                  Carburising 2)                                                                                               Salt bath (580 – 680 °C), case-hardening box, air                                                        4)


                                               Direct hardening              3)
                                                                                                   880   –   980                    °C                                 Oil (water), hot bath 160 – 250 °C 4)
                                                  Core refining                                    860   –   900                    °C                                 Oil (water), hot bath 160 – 250 °C 4)
                                                 Case refining                                     780   –   820                    °C                                 Oil (water), hot bath 160 – 250 °C 4)
See flap for footnotes                     Tempering (stress-relieving) 5)                         150   –   200                    °C                                                   Air



          Hardenability in the                               Distance from the quenched end in mm
          end-quench test
                                                                1.5               3            5         7                           9           11            13                     15                       20            25              30           35            40
Hardness in HRC
                                                 H
                                                max.            49                49        48        46                            43           42            41                     39                       37            35              34           33            32
                                                min.            41                39        36        33                            30           28            26                     25                       23            21               –            –             –

                                                HH
                                                max.            49                49        48        46                            43           42            41                     39                       37            35              34           33            32
                                                min.            44                42        40        37                            34           33            31                     30                       28            26              25           24            23

                                                 HL
                                                max.            46                46        44        42                            39           37            36                     34                       32            30              29           28            27
                                                min.            41                39        36        33                            30           28            26                     25                       23            21               –            –             –

          Hardenability diagram                                                                                             Time-temperature-transformation diagram
                                                                                                                            for continuous cooling

                 55                                                                                                               1200

                                                                                                                                  1100
                 50
                                                                                                                                  1000
                                                        HH-Sorte
                                                        HH grade
                                                        Überschneidung
                                                        Overlap of                                                                900
                 45                                     HH+HL-Sorte
                                                        HH + HL grade                                                                                                                                                                                           AC3
                                                        HL-Sorte
                                                        HL grade                                                                  800
                                                                                                               Temperatur in oC
                                                                                                             Temperature in °C




                 40                                                                                                               700                                                               60
                                                                                                                                                                                                                    60     65                                   AC1
                                                                                                                                                                         F                  60 60 60 40               40
                                                                                                                                                                                                                            35
                                                                                                                                                                                                40 40
                                                                                                                                  600                           10 25                            P
  Härte in HRC
Hardness inHRC




                                                                                                                                                                      35
                 35                                                                                                                         A                                        40
                                                                                                                                                                                           50
                                                                                                                                  500                                                                25
                                                                                                                                                                B
                                                                                                                                          MS           50           87
                 30                                                                                                               400                                        80 65
                                                                                                                                                                                      60
                                                                                                                                            M                                                   55
                                                                                                                                  300                                                                     45
                 25                                                                                                               200
                                                                                                                                                                                                                15


                                                                                                                                         Hardness
                                                                                                                                         Härtewerte values
                                                                                                                                  100                         405            342 302 274 263 238 212 187 171 160 182 162 153
                 20                                                                                                                         HV 10
                                                                                                                                    0
                                                                                                                                     100                101                       102                           103                    104                105                      106
                 15                                                                                                                   Time s
                                                                                                                                      Zeit inin s
                      0   5   10    15   20    25     30      35         40        45                                                                                         100                          101                   102                103                      104
                                                                                                                                                                               Time min
                                                                                                                                                                              Zeit in in min
                 Abstand von der abgeschreckten Stirnfläche in mm
                                   Distance from quenched end in mm                                                                                                                                                          100                  101                 102
                                                                                                                                                                                                                             Time h
                                                                                                                                                                                                                             Zeit inin h
                 28
                                                                CARBODUR® 20 MoCr 4 / 20 MoCrS 4
        Material No.
        Code
                                              Material No.               Designation                      Material No.                                    Designation

                                                1.7321                       20MoCr4                                           1.7323                     20MoCrS4


        Chemical
        composition
                                                                         C             Si             Mn                                   P                       S                         Cr                              Mo
  Typical analysis in %
                                               20 MoCr 4 0.17– 0.23                  ≤0.40      0.70 – 1.00                           ≤0.035            ≤0.035 0.30 – 0.60 0.40 – 0.50
                                              20 MoCrS 4 0.17– 0.23                  ≤0.40      0.70 – 1.00                           ≤0.035          0.020–0.040 0.30 – 0.60 0.40 – 0.50



        Hardness in various
        treatment conditions                        Treated for                          Treated                                      Soft-annealed A                              Annealed to spherical                                         Treated for ferrite-
                                                    shearing S                      for strength TH*                                                                                   carbides AC                                             pearlite structure FP**
 * For diameters up to 150 mm                           HB                                 HB                                                  HB                                          HB                                                             HB
 ** For diameters up to 60 mm
                                                        1)                             156 – 207                                           max. 207                                               max. 165                                               140 – 187


        Heat treatments
                                                Type of treatment                        Treatment temperature                                                                                                         Cooling

                                                 Case-hardening                                 880 – 980 °C                                                                       Oil (water), hot bath 160 – 250 °C,4)
                                                  Carburising 2)
                                               Direct hardening 3)                              880   –   980                    °C                                                       Oil, hot bath 160 – 250 °C                                        4)


                                                  Core refining                                 860   –   900                    °C                                                       Oil, hot bath 160 – 250 °C                                        4)


                                                 Case refining                                  780   –   820                    °C                                                       Oil, hot bath 160 – 250 °C                                        4)


 See flap for footnotes                    Tempering (stress-relieving) 5)                      150   –   200                    °C                                                                     Air



           Hardenability in the                              Distance from the quenched end in mm
           end-quench test
                                                                1.5            3            5         7                           9            11                  13               15                      20                25                    30             35            40
 Hardness in HRC
                                                 H
                                                max.            49             47        44        41                            38            35                  33               31                      28                26                    25             24            24
                                                min.            41             37        31        27                            24            22                   –                –                       –                 –                     –              –             –

                                                HH
                                                max.            49             47        44        41                            38            35                  33               31                      28                26                    25             24            24
                                                min.            44             40        35        32                            29            26                  24               22                       –                 –                     –              –             –

                                                 HL
                                                max.            46             44        40        36                            33            31                  29               27                      24                22                    21             20            20
                                                min.            41             37        31        27                            24            22                   –                –                       –                 –                     –              –             –

           Hardenability diagram                                                                                          Time-temperature-transformation diagram
                                                                                                                          for continuous cooling

                 55                                                                                                            1200

                                                                                                                               1100
                 50
                                                                                                                               1000
                                                        HH-Sorte
                                                        HH grade
                                                        Überschneidung
                                                        Overlap of                                                             900
                 45                                     HH+HL-Sorte
                                                        HH + HL grade                                                                                                                                                                                                    AC3
                                                        HL-Sorte
                                                        HL grade                                                               800
                                                                                                          Temperature in o°C
                                                                                                           Temperatur in C




                 40                                                                                                            700                                                   F
                                                                                                                                                                                             55        60         65     65       65 70        70                        AC1
                                                                                                                                                               3   5 10             25                                                              P
                                                                                                                                      A                                       15                  30    30         30        30    30     30   30
                                                                                                                                                                                         5
                                                                                                                               600
  Härte in HRC
Hardness inHRC




                 35                                                                                                                                            B
                                                                                                                               500
                                                                                                                                      MS
                                                                                                                                                          95
                 30                                                                                                            400                                 95
                                                                                                                                                                           95 95
                                                                                                                                      M                                              90      85
                                                                                                                                                                                                       70
                                                                                                                               300                                                                                15    10         5    5      5
                 25                                                                                                            200
                                                                                                                                      Hardness
                                                                                                                                      Härtewerte values
                                                                                                                               100                             370      283        260 240 238 228 210                 189    176 165 181         152
                 20                                                                                                                      HV 10                                                                                                 156    149
                                                                                                                                 0
                                                                                                                                  100                101                       102                            103                           104                    105                     106
                 15                                                                                                                Zeit in s
                                                                                                                                   Time in s
                      0   5   10    15   20    25     30      35         40     45                                                                                        100                               101                    102                       103                     104
                                                                                                                                                                          Time min
                                                                                                                                                                          Zeit in in min
                 Abstand von der abgeschreckten Stirnfläche in mm
                                   Distance from quenched end in mm                                                                                                                                                          100                         101                   102
                                                                                                                                                                                                                              Zeit in h
                                                                                                                                                                                                                              Time in h
                                                                                                                                                                                                                                                                                29
 CARBODUR® 20 NiCrMo 2-2 / 20 NiCrMoS 2-2
        Material No.
        Code
                                              Material No.               Designation                     Material No.                                     Designation

                                                1.6523                   20NiCrMo2-2                                          1.6526                     20NiCrMoS2-2


        Chemical
        composition
                                                                         C            Si             Mn                                     P                       S                                    Cr                            Ni                      Mo
  Typical analysis in %
                                          20 NiCrMo 2-2 0.17– 0.23                  ≤0.40      0.65 – 0.95                             ≤0.035              ≤0.035 0.35 – 0.70 0.40 – 0.70 0.15–0.25
                                         20 NiCrMoS 2-2 0.17– 0.23                  ≤0.40      0.65 – 0.95                             ≤0.035            0.020–0.040 0.35 – 0.70 0.40 – 0.70 0.15–0.25



        Hardness in various
        treatment conditions
                                                    Treated for                         Treated                                        Soft-annealed A                                 Annealed to spherical                                          Treated for ferrite-
                                                    shearing S                     for strength TH*                                                                                        carbides AC                                              pearlite structure FP**
 * For diameters up to 150 mm                           HB                                HB                                                        HB                                         HB                                                              HB
 ** For diameters up to 60 mm
                                                         1)                           161 – 212                                              max. 212                                                      max. 176                                             149 – 194


        Heat treatments
                                                Type of treatment                       Treatment temperature                                                                                                                    Cooling

                                                Case-hardening                                 880 – 980 °C                                                             Oil (water), hot bath 160 – 250 °C,
                                                  Carburising 2)                                                                                                Salt bath (580 – 650 °C), case-hardening box, air                                                                   4)


                                               Direct hardening 3)                             880   –   980                    °C                                                                  Oil, hot bath 160 – 250 °C                                  4)


                                                  Core refining                                860   –   900                    °C                                                                  Oil, hot bath 160 – 250 °C                                  4)


                                                 Case refining                                 780   –   820                    °C                                                                  Oil, hot bath 160 – 250 °C                                  4)


 See flap for footnotes                    Tempering (stress-relieving) 5)                     150   –   200                    °C                                                                                Air



           Hardenability in the                               Distance from the quenched end in mm
           end-quench test
                                                                1.5           3            5         7                           9               11             13                         15                    20                    25                 30              35            40
 Hardness in HRC
                                                 H
                                                max.             49           48        45        42                             36              33             31                         30                    27                    25                 24              24            23
                                                min.             41           37        31        25                             22              20              –                          –                     –                     –                  –               –             –

                                                HH
                                                max.             49           48        45        42                             36              33             31                         30                    27                    25                 24              24            23
                                                min.             44           41        36        31                             27              24             22                         21                     –                     –                  –               –             –

                                                 HL
                                                max.             46           44        40        36                             31              29             27                         26                    23                    21                 20              20             –
                                                min.             41           37        31        25                             22              20              –                          –                     –                     –                  –               –             –

           Hardenability diagram                                                                                         Time-temperature-transformation diagram
                                                                                                                         for continuous cooling

                 55                                                                                                           1200

                                                                                                                              1100
                 50
                                                                                                                              1000
                                                        HH-Sorte
                                                        HH grade
                                                        Überschneidung
                                                        Overlap of                                                            900
                 45                                     HH+HL-Sorte
                                                        HH + HL grade
                                                        HL-Sorte
                                                        HL grade                                                              800                                                                                F                                                          AC3
                                                                                                         Temperature in o°C




                                                                                                                                                                                                                                                    75
                                                                                                          Temperatur in C




                                                                                                                                                                                                                                 60     75
                 40                                                                                                           700                                        5
                                                                                                                                                                                 10
                                                                                                                                                                                               15        40      55
                                                                                                                                                                                                                      40          40         25          25                 AC1
                                                                                                                                                                1                                          10
                                                                                                                                                A                            1             5
                                                                                                                                                                                               P5
                                                                                                                              600
Hardnessin HRC
  Härte in HRC




                 35
                                                                                                                              500      MS
                                                                                                                                                                             B
                                                                                                                                                          65
                 30                                                                                                           400                                   85
                                                                                                                                                                                      96
                                                                                                                                                    M
                                                                                                                              300                                         97                        91
                                                                                                                                                                                                                84
                 25                                                                                                           200
                                                                                                                                                                                                                      79
                                                                                                                                                                                                                                 49
                                                                                                                                             453
                                                                                                                                       Härtewerte 453
                                                                                                                                       Hardness                                                                            234
                                                                                                                                                                                                                                             5
                                                                                                                              100      values
                 20                                                                                                                         HV 10         453            426 313               283 276 245 239                   210     182      159    148     140
                                                                                                                                0
                                                                                                                                     100                 101                           102                                 103                      104                   105                 106
                 15                                                                                                                  Zeit in s
                                                                                                                                     Time in s
                      0   5   10    15   20    25     30      35         40   45                                                                                             100                                 101                         102                    103                 104
                                                                                                                                                                             Time min
                                                                                                                                                                             Zeit in in min
                 Abstand von der abgeschreckten Stirnfläche in mm
                                  Distance from quenched end in mm                                                                                                                                                                     100                     101                102
                                                                                                                                                                                                                                       Zeit in h
                                                                                                                                                                                                                                       Time in h
                 30
                                                                                                           CARBODUR® 22 CrMoS 3-5
        Material No.
        Code
                                               Material No.                Designation

                                                 1.7333                    22CrMoS3-5


        Chemical
        composition
                                                 C                Si                 Mn           P                   S          Cr           Mo
  Typical analysis in %
                                              0.19–0.24         ≤0.40           0.70–1.00       ≤0.035       0.020–0.040 0.70 –1.00 0.40 – 0.50




        Hardness in various
        treatment conditions
                                                     Treated for                          Treated                     Soft-annealed A        Annealed to spherical       Treated for ferrite-
                                                     shearing S                      for strength TH*                                            carbides AC           pearlite structure FP**
 * For diameters up to 150 mm                            HB                                 HB                              HB                       HB                           HB
 ** For diameters up to 60 mm
                                                      max. 255                            170 – 217                       max. 217                   max. 180                   152 – 201


        Heat treatments
                                                 Type of treatment                         Treatment temperature                                             Cooling

                                                Case-hardening                                  880 – 980 °C                                  Oil (water), hot bath 160 – 250 °C,
                                                  Carburising 2)                                                                      Salt bath (580 – 650 °C), case-hardening box, air     4)


                                               Direct hardening 3)                              880   –    980   °C                                Oil, hot bath 160 – 250 °C   4)


                                                  Core refining                                 860   –    900   °C                                Oil, hot bath 160 – 250 °C   4)


                                                 Case refining                                  780   –    820   °C                                Oil, hot bath 160 – 250 °C   4)


 See flap for footnotes                    Tempering (stress-relieving) 5)                      150   –    200   °C                                              Air



          Hardenability in the                                 Distance from the quenched end in mm
          end-quench test
                                                                  1.5            3          5         7           9        11         13      15        20      25       30          35      40
 Hardness in HRC
                                                  H
                                                 max.             50            49         48         47         45        43         41      40        37      35       34          33      32
                                                 min.             42            41         37         33         31        28         26      25        23      22       21          20       –

                                                 HH
                                                 max.             50            49         48         47         45        43         41      40        37      35       34          33      32
                                                 min.             45            44         41         38         36        33         31      30        28      26       25          24      23

                                                  HL
                                                 max.             47            46         44         42         40        38         36      35        32      31       30          29      28
                                                 min.             42            41         37         33         31        28         26      25        23      22       21          20       –

          Hardenability diagram


                 55

                 50
                                                          HH-Sorte
                                                          HH grade
                                                          Überschneidung
                                                           Overlap of
                 45                                       HH+HL-Sorte
                                                          HH + HL grade
                                                          HL-Sorte
                                                          HL grade
                 40
  Härte in HRC
Hardness inHRC




                 35

                 30

                 25

                 20

                 15
                      0   5   10    15   20     25     30       35         40    45
                 Abstand von der abgeschreckten Stirnfläche in mm
                                   Distance from quenched end in mm

                                                                                                                                                                                            31
                                     Hardenability

Effect of alloying elements          Fig. 1 shows an example of the ef-                                    For reasons of toughness, the
on hardenability                     fect of alloying elements on the                                      carbon content is limited to about
Based on the composition of the      hardenability of various case-                                        0.25%. The element silicon also
alloys, case-hardening steels can    hardening steels according to                                         increases hardenability. It is, how-
be classified as:                    DIN 10 084 in the end-quench                                          ever, hardly ever used as an alloy-
• unalloyed                          test. The hardness at a distance                                      ing element in case-hardening
• chrome-alloyed                     of 1.5 mm from the end surface is                                     steels because it encourages sur-
• manganese-chrome and molyb-        largely determined by the carbon                                      face oxidation on carburising. In
 denum-chrome-alloyed                content. The shape of the rest of                                     special cases, boron is used as
• nickel-chrome-alloyed              the end-quench test curve is also                                     an alloying element to increase
• nickel-chrome-molybdenum-          influenced by the quantities of                                       hardenabililty or impact tough-
 alloyed and                         other elements, such as molyb-                                        ness in chrome-manganese
• chrome-nickel-molybdenum-          denum, manganese, chrome and                                          steels.
 alloyed case-hardening steels.      nickel, that tend to increase hard-                                   In the case of some unalloyed
                                     enability. Given small cross-                                         case-hardening steels, the effect
The alloying elements affect the     sections, through-hardening is                                        of a coarse-grain austenite struc-
hardenability of the base material   possible with chrome or chrome-                                       ture is used to increase hardness.
and the hardenability of the car-    manganese steels, while higher
burised surface layer.               quantities of molybdenum and
                                                                                                case-hardening steels
                                     nickel must be added to                               50

The hardenability of the base        achieve through hardening
material is identified by means of   of large cross-sections.                              40
                                                                                                                           18 CrNiMo 7-6
the end-quench test according to
                                                                                           30
DIN 50 191 and is an important
                                                                         Hardness in HRC




                                                                                                                            17 CrNi 6-6
parameter for determining
                                                                                           20
hardness in the core, since case-                                                                                                    20 MoCr 4
                                                                                                     17 Cr 3
hardened components are only
                                                                                           10
                                                                                                                             16 MnCr 5
tempered at low temperatures, up
                                                                Fig. 1
to approximately 180 °C, in order         Effect of alloying elements
                                                                                                0          10        20         30           40   50
                                        on the hardenability of case-
                                                                                                Distance from quenched end in mm
to ensure high surface hardness.                     hardening steels




 32
                                                                                                              Technical information




Quite apart from their influence      carburisation, the heating and        Fig. 2 shows the case depth of
on hardness in the core, the          cooling conditions during hard-       various case-hardening steels
hardness and the hardness profile     ening and the hardenability in the    with the same carbon distribution
in the carburised surface layer       carburised surface layer.             in the surface layer. According to
have an important effect on the       Correlations valid for the base       this, case depth of the 17 Cr 3
properties of case-hardened           material cannot be applied to the     steel (0.80 mm) is doubled in the
components. A surface hardness        hardenability of the surface layer,   17 CrNi 6-6 steel (1.56 mm) due to
of 57 - 63 HRC has proved to the      since the effect of alloying ele-     the different alloy contents under
best for optimum wear resistance.     ments on hardenability also           otherwise identical conditions.
                                                                                                                    (acc. to U. Wyss)
This degree of hardness is            depends on the carbon content.                                          %

achieved largely independently of     Up to a carbon content of about                                        0.90
                                                                                                                                                       17 Cr 3
                                                                                                                                                       20 NiCrMo 2-2
                                                                                                             0.80
the steel composition, with a car-    0.5%, the improvement in harden-                                                                                 20 MoCr 4
                                                                                                                                                       16 MnCr 5
                                                                             Carbon content in % by weight




                                                                                                             0.70       C                              20 NiMoCr 6-5
bon content at the surface of         ability brought about by molyb-                                                                                  17 CrNi 6-6
                                                                                                             0.60           0.60
some 0.7%. Higher carbon con-         denum, chrome and manganese
                                                                                                             0.50
                                                                                                                                   0.46          1.50 mm
tents in the surface layer provide    increases, only to drop again at
                                                                                                             0.40                  0.39
                                                                                                                                        0.37       0.35 % C
only a slight increase in hardness.   higher carbon contents.                                                0.30
                                                                                                                                   0.34 0.33


Supercarburisation in the surface                                                                            0.20
                                                                                                                                                1.42
                                                                                                                                                1.56




layer may result in reduced                                                                                  0.10       Eht
                                                                                                                                           1.35
                                                                                                                                    0.80

                                                                                                                                           1.16

                                                                                                                                           1.52




toughness due to precipitation of                                                                              0
                                                                                                                    0       0.4    0.8     1.2   1.6   2.0    2.4   2.8
                                                                                                                Distance from the surface in mm
secondary cementite and a
hardness loss caused by increas-                                            Fig. 2: Case depth of various case-harden-
                                                                            ing steels with the same carbon profile
ing proportions of residual aus-                                            (acc. to U. Wyss)

tenite.


The case depth, defined as the
distance from the surface of a
case-hardened workpiece to the
point whose Vickers hardness is
usually 550 HV1 (see DIN 50 190),
is determined by the depth of


                                                                                                                                                                     33
Suitability for direct                                                                                                        direct hardening are satisfactory                                     steels with 1.6 to 1.8% chrome is
hardening                                                                                                                     fine-grain stability at the carburis-                                 appreciably higher than, for exam-
An important criterion in the                                                                                                 ing temperature and low residual                                      ple, in the 20 MoCr 4 steel with
choice of a case-hardening steel                                                                                              austenite after hardening. The                                        approximately 0.4% chrome. The
is its suitability for direct harden-                                                                                         residual austenite content after                                      hardness decreases at carbon
ing. The most common methods                                                                                                  hardening increases with increas-                                     contents > 0.7% at the surface,
of case hardening are direct hard-                                                                                            ing chrome content and carburis-                                      which increases the proportions
ening (Fig. 10, Hardening from the                                                                                            ing temperature. Fig. 3 illustrates                                   of residual austenite (Fig. 4).
                                                                                                                                                                                         direct hardening
carburisation heat) and single                                                                                                this relationship, using the
                                                                                                                                                                                   900
hardening after cooling from the                                                                                              20 MoCr 4, 20 NiMoCr 6 5,
                                                                                                                                                              Hardness in HV 0.5




                                                                                                                                                                                   800
case (Fig. 11). Mainly for reasons                                                                                            16 MnCr 5, 20 MnCr 5,                                700                         Direct hardening
                                                                                                                                                                                                               925 °C/oil
of cost effectiveness, direct hard-                                                                                           17 CrNi 6-6 and 18 CrNi 8                            600

                                                                                                                                                                                   500
ening is increasingly being given                                                                                             steels as examples.                                                                         20 MoCr 4
                                                                                                                                                                                   400
                                                                                                                                                                                                                          20 NiMoCr 6-5
preference in mass production                                                                                                 Although differences in the                          300                                    18 CrNi 8
                                                                                                                                                                                                                          16 MnCr 5
methods (see chapter on Heat                                                                                                  proportions of residual aus-                               0   0.1 0.2 0.3    0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2 1.3
                                                                                                                                                                                                               Carbon Content in % by weight
Treatment).                                                                                                                   tenite in the various steels
The prerequisites for the suitability                                                                                         remain relatively small at carbu-                                                  Fig. 4: Hardness as a function of
                                                                                                                                                                                                                the carbon content of the surface
of a case-hardening steel for                                                                                                 rising temperatures around 900 °C                                                        layer after direct hardening

                        100
                                         chrome content of the steels tested                                                  with subsequent direct hardening,
                                                                                   Carborising time: 3 h
                                                      20 NiMoCr 6-5




                                    90                                                                                        they increase rapidly and pro-                                        The suitability of a steel for direct
                                          20 MoCr 4




                                                                                  20 MnCr 5
                                                                      16 MnCr 5




                                    80
                                                                                                                              gressively at higher carburising                                      hardening can also be identified
                                                                                                                  18 CrNi 8
  Residual austenite content in %




                                    70
                                                                                                    17 CrNi 6-6




                                    60
                                                                                                                              temperatures. For economic rea-                                       by the range of carbon contents
                                       Carborising
                                    50 temperature                                                                            sons, however, ever higher car-                                       at the surface with which a cer-
                                       in °C:     1000
                                    40
                                                                                              950                             burising temperatures are being                                       tain minimum hardness can be
                                    30
                                                                                                                              aimed at for direct hardening.                                        achieved. According to this, the
                                    20

                                    10                                                                  900
                                                                                                                              Given the same carburising time                                       20 MoCr 4 steel is more suitable
                                     0
                                          0.4 0.6 0.8 1.0 1.2 1.4                                   1.6           1.8
                                                                                                                              and the same carbon potential in                                      for direct hardening than, for
                                         Chrome content in % by weight
                                                                                                                              the carburising medium, the pro-                                      example, the 18 CrNi 8 steel.
Fig. 3: Residual austenite content as a                                                                                       portion of residual austenite in                                      Advances in the development of
function of chrome content and carburis-
ing temperature                                                                                                               the 17 CrNi 6-6 and 18 CrNi 8                                         modern gas carburising plants,


 34
                                                                                                                                                                                       Technical information




with their precise, specific control                                                                                                          remains bound in the form of car-    and torsional stresses, the fatigue
of the carbon potential and the                                                                                                               bide (Fig. 10 and 11).               strength increases with increasing
carburising cycle, mean that                                                                                                                                                       case depth and core strength. In
practically all case-hardening                                                                                                                Fatigue strength                     the unusual case of tensile/com-
steels can be direct-hardened,                                                                                                                In addition to higher wear resis-    pression stressing, the signifi-
regardless of their alloy content.                                                                                                            tance, case-hardened steels          cance of the core strength in-
Fig. 5 shows the different carbon                                                                                                             should also exhibit high strength    creases. The alloying elements
contents at the surface that have                                                                                                             under dynamic stressing. On          affect fatigue strength through the
to be chosen for various case-                                                                                                                hardening a cross-section with a     hardenability in the core and the
hardening steels in order to en-                                                                                                              carburised surface layer, the        surface layer and also through the
sure maximum surface hardness.                                                                                                                lower-carbon core undergoes          residual austenite content.
                                                                                                                                              transformation before the high-
 Carbon content in the surface layer in % by weight




                                                      0.9
                                                                                                                                              carbon surface layer due to the

                                                      0.8                                                                                     higher martensite temperature.
                                                                                                                                              Since the martensite transforma-
                                                      0.7
                                                                                                                                              tion is accompanied by an in-
                                                                                                                                              crease in volume, high internal
                                                                                                  17 CrNi 6-6
                                                                                      20 MnCr 5
                                                                          16 MnCr 5
                                                             20 MoCr 4




                                                      0.6
                                                                                                                      18 CrNi 8




                                                                                                                                              compression stresses develop
                                                      0.5
                                                            0.3 0.5 0.7 0.9 1.1 1.3 1.5                         1.7               1.9   2.1   that are balanced by internal ten-
                                                            Chrome content in % by weight
                                                                                                                                              sile stresses. The compression
Fig. 5: Carbon content in the surface                                                                                                         stresses in the surface layer
layer targeted during direct hardening
to obtain maximum possible hardness                                                                                                           counteract the external, usually
as a function of the chrome content
                                                                                                                                              tensile, stresses and thus in-
                                                                                                                                              crease the fatigue strength.
The proportions of residual aus-
tenite are appreciably lower after                                                                                                            The fatigue strength of case-
single hardening since, on hard-                                                                                                              hardened components also
ening from lower temperatures                                                                                                                 depends on the ratio of the car-
adjusted to the carbon content at                                                                                                             burised surface layer to the non-
the surface, any excess carbon                                                                                                                carburised section. With bending


                                                                                                                                                                                                                      35
Austenite grain size                   Toughness of the surface             To date, no standard test for the
Fine-grain stability in case-          layer under impact loading           characterisation of the impact
hardening steels is particularly       Case-hardened components must        toughness of case-hardened
important at the high tempera-         remain ductile under high dynam-     steels has been accepted. One
tures reached during direct hard-      ic stressing in order to avoid       frequently used method is the
ening, due to the fact that grain      brittle factures. Since the high-    Brugger test, with which the
growth with coarse or mixed grain      carbon martensite in the surface     maximum impact strength of a
can lead to the danger of distor-      layer exhibits only low toughness,   case-hardened notched impact
tion and reduced toughness. By         the toughness of the component       specimen is measured.
selectively balancing the quanti-      is determined largely by the
ties of aluminium and nitrogen,        depth of the carburised surface
the inhibiting effect of aluminium     layer and the toughness of the
nitride precipitations on grain        core material. The impact tough-
growth can be used to achieve a        ness of the component dimin-
largely stable fine-grain structure.   ishes with increasing case depth.
According to DIN 17 210, fine          For reasons connected with the
grain structure is assured after       fatigue strength, however, the
treatment at 930 +/- 10 °C/4 h/        case depth should not be too
water. Prior hot forming and heat      small. The toughnesss of the sur-
treatments can have a significant      face layer can be improved by
effect on the stability of the fine    choosing a nickel content > 1.5%.
grain. In disputed cases, anneal-
ing treatment at 1150 °C/30 min/
air is recommended as pre-
treatment, in order to produce a
uniform initial state.




 36
                                                                                                     Technical information




               Machining and heat treatment

Chipless forming                       steels tend to “smear” and form                       Heat treatments for as-
Case-hardening steels are well         built-up edges. In such cases,                        supplied conditions
suited to hot forming. Due to the      heat treatment to a particular                        Depending on the product con-
low carbon content, they possess       strength (“TH”) is of advantage.                      cerned and the anticipated pro-
good cold-working properties           With high-alloy nickel-chrome or                      cessing, case-hardening steels
that, however, deteriorate with        nickel-chrome-molybdenum case-                        can be supplied in various treated
increasing carbon and alloy con-       hardening steels, the transition to                   conditions. The most important
tents. Depending on the chemical       the ferrite-pearlite stage is often                   heat treatments are described
composition, the choice of a suit-     incomplete, leaving traces of                         below. Table 1 provides an over-
able structure (AC, FP) can im-        bainite and a banded structure                        view of the Brinell hardness
prove cold-forming properties.         that reduce machinability. These                      values that should be chosen for
                                       steels are therefore also ma-                         these conditions.
Chip machining                         chined in the AC-annealed condi-
Chip machining of case-harden-         tion.                                                 Treatment for shearing S
ing steels is affected by the struc-                                                         (Fig. 6, Curve 1)
tural state, the strength and non-     Case-hardening steels are fre-                        Appropriate cooling and/or
metallic inclusions (sulphides,        quently produced with a con-                          annealing to achieve a maximum
oxides).                               trolled sulphur content of 0.020 -                    hardness of 255 HB.
                                       0.035%. Machinability is then
                                                                                              Fig. 6: Schematic representation of the
Ferritic-pearlitic structures, such    improved by an increase in sul-                                 temperature/time profile when
                                                                                      treating for shearing (S), soft-annealing (A) and
as can be achieved with un-            phide inclusions. Deliberate con-                         annealing to spherical carbides (AC)

alloyed or low-alloy case-harden-      trol of the oxide inclusions
                                                                                                                                  AC3
ing steels like Ck 15 and 17 Cr 3      (calcium treatment) also
by controlled cooling from the         allows the machinability of                                                                AC1



forming temperature, are espe-         case-hardening steels to                                         2 Soft annealing, A
                                                                                                                                        4
                                                                        Temperature




                                                                                                                              3
cially well suited for chip machin-    be changed for the better.                              1
                                                                                                                                   annealing to spherical, AC
                                                                                      Treating for

ing. Special heat treatment (FP                                                       shearing, S




annealing) is required for higher-
alloyed steels. At very low hard-
ness values, case-hardening                                                                             Time




                                                                                                                                                     37
                 Steel grade                                            Hardnesses in treated condition1)

    Code name             Material No.              S               A                   TH1)                      FP2)                AC
                                              (treated for   (soft-annealed)       (treated for          (treated for ferrite-   (annealed to
                                               shearing)                             strength)            pearlite structure) spherical carbides)

                                               HB max.          HB max.                  HB                       HB              HB max.

  C 15 E                       1.1141              –              143                    –                        –                  135
  C 15 R                       1.1140              –              143                    –                        –                  135

  17 Cr 3                      1.7016              –              174                    –                        –                  155

  16   MnCr 5                  1.7131              –              207              156   to   207           140   to   187           165
  16   MnCrS 5                 1.7139              –              207              156   to   207           140   to   187           165
  20   MnCr 5                  1.7147             255             217              170   to   217           152   to   201           180
  20   MnCrS 5                 1.7149             255             217              170   to   217           152   to   201           180

  20 MoCr 4                    1.7321             255             207              156 to 207               140 to 187               165
  20 MoCrS 4                   1.7323             255             207              156 to 207               140 to 187               165

  22 CrMoS 3-5                 1.7333             255             217              170 to 217               152 to 201               180

  20 NiCrMo 2-2                1.6523            2553)            212              161 to 212               148 to 194               176
  20 NiCrMoS 2-2               1.6526            2553)            212              161 to 212               148 to 194               176

  20 NiMoCrS 6-5               1.6757             255             220              170 to 220               155 to 205               180

  17 CrNi 6-6                  1.5918             255             229              175 to 229               156 to 207               178
  18 CrNi 8                    1.5920             255             225              179 to 229               158 to 205               180

  18 CrNiMo 7-6                1.6587             255             229              179 to 229               159 to 207               180

  15 NiCr 13                   1.5752             255             229              179 to 229               166 to 217               180


Table 1: Brinell hardness in various treatment conditions                                           1)
                                                                                                       For diameters up to 150 mm
                                                                                                    2)
                                                                                                       For diameters up to 60 mm
                                                                                                    3)
                                                                                                       Can be sheared in as-rolled condition

Soft annealing A
(Fig. 6, Curve 2)
Heat treatment for reducing the
hardness of a workpiece to
values below a certain prescribed
value.


 38
                                                                                                                                                                                                                            Technical information




                                                                                                                                                                                      transformation temperatures in
                                       TTT-Diagram (continous)
                            1000
                                                                                                                                                                                      the pearlite stage for the most
                             900
                                                                                                                      AC3                                                       AC3
  Temperature




                             800                                                                                                                                                      common case-hardening steels.
                             700                                                                                      AC1                                                       AC1
                             600
                                                    A
                                                                                P
                                                                                                                                                                                      The transformation time depends
                                                                          F
                                                        2         1                                                                    1
                             500
                                                                           B                                                                                                          on the temperature cycle, the size
                             400            MS                                  1
                             300                                                                                                                                                      of the workpiece and the state of
                                                      M                                                                                        3
                             200
                             100
                                                                                                                                                                                      nucleation of the austenite after
                                  0                                                                                                                                                   forging. Considerably longer
                                                                Time (log.)                           t                                               Time in h                  t
                                            = Start of transformation                     A Austenite range                                B       range of bainite structure         transformation times are neces-
                                            = End of transformation                       F Ferrite range                                  M       Martensite range
                                                                                                                                                                                      sary at other transition tempera-
                                                                                          P Pearlite range
                                                                                                                                                                                      tures in the pearlite stage.
Fig. 7: Schematic representation of the temperature/time profile for
TH annealing ➀, hardening ➁ und tempering ➂                                                                                                                                                                                                                     20 NiMoCr 6-5
                                                                                                                                                                                       transition temperature in °C




                                                                                                                                                                                                                      650

                                                                                                                                                                                                                      660                                  18 CrNiMo 7-6


Treating for strength (TH)                                                                                              Treating for ferrite-pearlite                                                                 650                              18 CrNi 8




                                                                                                                                                                                                                                                                                            Temperature in °C
                                                                                                                                                                                                                      660                  20 MoCr 4

(Fig. 7, Curve 1)                                                                                                       structure (FP)                                                                                650            17 CrNi 6-6

                                                                                                                                                                                                                      640                  20 NiMoCr 2-2

Heat treatment with appropriate                                                                                         (Fig. 8, Curve 1)                                                                             640            20 MnCr 5

                                                                                                                                                                                                                      640        16 MnCr 5

cooling and subsequent temper-                                                                                          (also called “pearlitising, isother-
                                                                                                                                                                                                                            0       20         40          60        80         100   120
                                                                                                                                                                                                                            Pearlitising time in minutes
ing in order to achieve a certain                                                                                       mal annealing”) Isothermal trans-
range of hardness.                                                                                                      formation, consisting of austenit-                            Fig. 9: Time ranges for complete
                                                                                                                                                                                      transformation to pearlite for various case-
                                                                                                                        ising, subsequent cooling to a                                hardening steels (austenitising temperature
                                                                                                                                                                                      range 870-900 °C)
                                  TTT-Diagram (isothermal)                                                                                 temperature in the pearlite                * Acc. to P. G. Dressel and H. Gulden
                      1000

                            900                                                                                                            stage and holding, so that
                                                                                                                         AC3
        Temperature in oC




                            800

                            700                                                                                           AC1
                                                                                                                                           the austenite is trans-                    Annealing to spherical
                                                                  F
                                        A                                                 1
                            600
                                                                           P
                                                                                                                                           formed completely into                     carbides AC (Fig. 6, Curves 3, 4)
                            500
                                                                            B
                            400         MS
                                                                                                                                           ferrite-pearlite. Fig. 9                   Annealing with the aim of spher-
                                             M
                            300
                                                                                                                                           shows the shortest trans-                  oidising the carbides. This gener-
                            200

                            100                                                                                                            formation times at ideal                   ally comprises holding for a
                             0
                                                                        Time (log.)           t
                                                                                                                                                                                      lengthy period of time at a tempe-
                                      = Start of transformation       A Austenite range           B       range of bainite structure
                                                                                                                                           Fig. 8: Schematic representation           rature near AC1, oscillating about
                                      = End of transformation         F Ferrite range             M Martensite range
                                                                                                                                             of the temperature/time profile
                                                                      P Pearlite range
                                                                                                                                                        for pearlitising (FP)         this temperature, if necessary.


                                                                                                                                                                                                                                                                                      39
                      Case-hardening treatment

Case hardening consists of the         A distinction is therefore made        piece exhibit different AC3 and MS
following stages:                      between:                               temperatures and also different
1. Carburising of the surface          Powder carburising,                    transformation behaviour.
      layer to certain case depths     Salt bath carburising,                 The most favourable hardening
      and certain carbon contents in   Gas carburising.                       temperatures for the core are
      the layer.                                                              approx. 100 °C above those for
2. Subsequent hardening.               The quantity of carbon introduced      the surface layer (see Material
3. Tempering (stress-relieving).       into the surface layer is primarily    Data Sheets, Page 22 ff.). In prac-
                                       dependent on the carburising           tice, this behaviour leads to
For the carburising and hardening      effect of the medium. The case         various treatment cycles.
stages, there are various proven       depth depends mainly on the
processing cycles that are             temperature and duration of the
chosen on the basis of technical       treatment. Since the rate of diffu-
and economic aspects.                  sion increases with rising tempe-
                                       ratures, the time required to reach
Carburising                            the desired case depth is reduced
Carburising means the thermo-          at higher temperatures. Similarly,
chemical treatment of a work-          the gradient of the carbon con-
piece in the austenitic condition      tent from the surface to the core
with the aim of enriching the sur-     becomes flatter.
face layer with carbon. After this                                            Hardening
treatment, the carbon is usually in    In order for the surface hardness to   (Fig.7, Curve 2)
the austenite in solid solution.       be high enough and, at the same        Hardening is taken to mean heat
                                       time, for residual austenite and       treatment consisting of austenitis-
Carburising takes place in a           secondary cementite to be elimi-       ing and cooling, under conditions
medium which releases carbon.          nated as far as possible, it is nec-   leading to an increase in hard-
The carburising medium can be a        essary to aim for a carbon content     ness due to more or less com-
solid (powder), liquid or gas.         at the surface which is below that     plete transformation of the aus-
                                       of the eutectic composition.           tenite into martensite and possi-
                                       In line with their carbon content,     bly bainite.
                                       the surface and core of the work-

 40
                                                                                                               Technical information




Quenching after carburising is                                                                             Single hardening
                                                         Carburisation (gas or salt bath)
preferably carried out in oil. For                                                         Ac3 (core)
                                                                                           Ac3 (surface)
                                                                                                           Single hardening means a single
                                           Temperature




                                                                 V       Hardening (oil)
workpieces of complicated de-                                                                              hardening process carried out
                                                                                Tempering
sign, hot bath hardening at ap-                                                                            after prior carburising and cooling
                                                                 Time
proximately 160 - 250 °C, fol-        10                 Direkthärten    Direct Hardening                  to ambient temperature. If car-
lowed by cooling in air, is advis-    Fig. 10: Direct hardening                                            burising is followed by isothermal
able. For coarser workpieces of                                                                            transformation, this is referred to
simple design, quenching in water     The time required for the case-                                      as single hardening with isother-
can be chosen. In order to trans-     hardening of steels can be con-                                      mal transformation.
form larger proportions of residu-    siderably reduced by ensuring a
al austenite into martensite after    high carbon potential during the                                     In the case of single hardening,
hardening, final subzero cooling      actual carburising phase and the                                     the carburised parts are first
to -180 °C can be carried out, e.g.   subsequent diffusion period,                                         cooled slowly in the carburising
on CrNi and CrNiMo steels.            and/or by using high tempera-                                        vessel and then hardened in the
                                      tures. Since higher carburising                                      usual way, possibly after interme-
Direct hardening (Fig. 10)            temperatures have a negative                                         diate treatment. The hardening
Direct hardening means quench-        effect on attempts to minimise                                       temperatures used usually lie just
ing immediately after carburising     distortion when quenching, it is                                     above the AC3 point of the surface
treatment that has been carried       expedient to let the temperature                                     layer. It is, however, also possible
out in the austenite temperature      drop somewhat after carburising                                      to choose hardening tempera-
range.                                and then quench from a lower                                         tures that are just above or below
During the direct hardening of        temperature that is still sufficient                                 the AC3 point of the core.
case-hardening steels, quenching      for hardening (denoted V). This is
is carried out immediately after      especially true for parts with a
carburising, either directly from     complex design. Distortion can
the case temperature or after a       be minimised in this way.
short pause (V in Fig. 10). This
method is mainly used in connec-
tion with gas carburising in the
mass production of gearing com-
ponents.

                                                                                                                                             41
Single hardening after cool-                           hardening lie in the fact that the                               face layer. Traces of residual aus-
ing from the case (Fig. 11)                            non-carburised area remains                                      tenite should favour smooth run-
When hardening from tempera-                           machinable, even after quench-                                   ning of gear wheels, for example,
tures just slightly above the AC3                      ing, and that distortion remains                                 and also facilitate running-in.
value for the surface, only partial                    negligible due to the low harden-                                Quite apart from that, a surface
transformation occurs in the core                      ing temperature.                                                 layer absolutely free of residual
                                                                    The disadvantage is that                            austenite is, for many alloyed
               Carburisation
                                  C                 Ac3 (core)      low toughness in the core                           case-hardening steels, virtually
                                                    Ac3 (surface)
 Temperature




                                  Hardening (oil)
                                                                    must be expected.                                   impossible without the use of
                  Cooling             Tempering
                  (case or air)                                                                                         special methods (e.g. low-
               Time
                                                                    When hardening from tem-                            temperature treatments)
Fig. 11: Single hardening after cooling                peratures that are above the AC3
from the case
                                                       temperature of the core (C in Fig.                               Single hardening after inter-
because the hardening tempera-                         11), the core undergoes complete                                 mediate annealing (Fig. 12)
ture is then under the AC3 value                       transformation, becomes fine-                                    In certain cases, for example the
for the core. The core then re-                        grained and thus gains in strength                               elimination of distortion caused
mains soft and can have a coarse                       and toughness. Although the                                      by carburising and cooling, it can
structure as a result of the long                      grain of the surface layer then                                  be expedient to introduce an
holding time at the high carburis-                     becomes somewhat coars-
                                                                                                        Carburisation
ing temperature. In the case layer,                    er, any cementite lattice is                                                                 C                Ac3 (core)
                                                                                                                           Intermediate annealing       Hardening    Ac3 (surface)
                                                                                          Temperature




                                                                                                                                                        (oil)        Ac1 (core)
on the other hand, a hard, fine-                       dissolved and surface em-
                                                                                                           Cooling
                                                                                                           (case or air)                                 Tempering
grain, homogeneous structure                           brittlement eliminated.
                                                                                                        Time
develops that provides good wear                       Since, on hardening from
and fatigue strength properties. If                    high temperatures, the amount of                                                         Fig. 12 Single hardening
                                                                                                                                            after intermediate annealing
cementite has formed, precipi-                         residual austenite in the carbu-
tated out at the grain boundaries                      rised surface layer increases with                               intermediate processing stage
as a lattice pattern, the low hard-                    increasing carbon content, espe-                                 before hardening. To this end, the
ening temperature is not sufficient                    cially with alloyed case-hardening                               parts are subjected to interme-
to dissolve the cementite lattice.                     steels, it is advisable to aim for a                             diate annealing below the AC1
The advantages of this method of                       lower carbon content in the sur-                                 temperature.


 42
                                                                                                                                                            Technical information




Single hardening after iso-                                                                         Double hardening (Fig. 14)                          Tempering
thermal transformation                                                                              Double hardening means two                          (Fig. 7, Curve 3)
(Fig. 13)                                                                                           stages of hardening, in which                       Tempering means the single or
This method of treatment is suit-                                                                   quenching is generally carried out                  repeated heating of a hardened
able for high-alloy case-hardening                                                                  from different temperatures.                        workpiece to a prescribed tem-
steels (e.g. 18 CrNi 8) that show a                                                                 With carburised workpieces, the                     perature (< AC1), holding at this
tendency to stress corrosion                                                                        first hardening process can be                      temperature and subsequent
                                                                                                               direct hardening, while the              appropriate cooling.
                   Carburisation
                                                C                                            Ac3 (core)        second is carried out from
                                                Hardening (oil)                              Ac3 (surface)
     Temperature




                                                                                             Pearlite stage
                    Salt bath                                                                (core)            a lower temperature.                     After hardening, it is advisable to
                    Isothermal transformation       Tempering
                                                                                                                                                        temper the workpieces at 150 -
                           Time           t
13
                   Single hardening after isothermal transformation                                            Double hardening is usual-               180 °C for unalloyed steels and at
Fig. 13: Single hardening after isothermal                                                          ly used when tough surface layers                   170 - 210 °C for alloyed steels.
transformation
                                                                                                    and core zones are required,                        Martensite tempered in this way
cracking after cooling in air from                                                                  together with greater case depth.                   has less of a tendency to form
the case, due to differences in the                                                                 Double hardening is generally                       grinding cracks. The hardness in
transformation rates between the                                                                    carried out first from the AC3                      the surface layer drops only
surface and the core.                                                                               temperature of the core and then                    slightly (approx. 1 - 2 HRC).
                                                                                                    from the AC3 temperature of the
                                                                                                    surface area. The tendency to
                                                                                                    distortion is greatest with double
                                                                                                    hardening.

                                                                                    Carburisation
                                                                                                                                        Ac3 (core)
                                                                                                                                        Ac3 (surface)
                                                                      Temperature




                                                                                                              Hardening (oil)
                                                                                     Hardening
                                                                                     (oil)                      Tempering


                                                                                           Time
                                                                  4                                 Double hardening


                                                                                                                         Fig. 14: Double hardening




                                                                                                                                                                                           43
                             Overview of grades
                          and chemical composition
                        Overview of grades                                              Chemical composition
                                                                               Main alloy contents in % (typical values)
 Carbodur                      Code name        Material No.      C           Si        Mn       P max.       S            Cr        Ni         Mo


 Carbodur C 15 E               C 15 E               1.1141     0.12-0.18    ≤0.40    0.30-0.60   0.035      ≤0.035         –          –          –
 Carbodur C15 R                C15 R                1.1140     0.12-0.18    ≤0.40    0.30-0.60   0.035    0.020-0.040      –          –          –


 Carbodur 17 Cr 3              17 Cr 3              1.7016     0.14-0.20    ≤0.40    0.60-0.90   0.035       ≤0.035     0.70-1.00     –          –


 Carbodur 16 MnCr 5            16 MnCr 5            1.7131     0.14-0.19    ≤0.40    1.00-1.30   0.035       ≤0.035     0.80-1.10     –          –
 Carbodur 16 MnCrS 5           16 MnCrS 5           1.7139     0.14-0.19    ≤0.40    1.00-1.30   0.035    0.020-0.040   0.80-1.10     –          –
 Carbodur 20 MnCr 5            20 MnCr 5            1.7147     0.17-0.22    ≤0.40    1.10-1.40   0.035       ≤0.035     1.00-1.30     –          –
 Carbodur 20 MnCrS 5           20 MnCrS 5           1.7149     0.17-0.22    ≤0.40    1.10-1.40   0.035    0.020-0.040   1.00-1.30     –          –


 Carbodur 20 MoCr 4            20 MoCr 4            1.7321     0.17-0.23    ≤0.40    0.70-1.00   0.035      ≤0.035      0.30-0.60     –       0.40-0.50
 Carbodur 20 MoCrS 4           20 MoCrS 4           1.7323     0.17-0.23    ≤0.40    0.70-1.00   0.035    0.020-0.040   0.30-0.60     –       0.40-0.50


 Carbodur 22 CrMoS 3-5         22 CrMoS 3-5         1.7333     0.19-0.24    ≤0.40    0.70-1.00   0.035    0.020-0.040   0.70-1.00     –       0.40-0.50


 Carbodur 20 NiCrMo 2-2        20 NiCrMo 2-2        1.6523     0.17-0.23    ≤0.40    0.65-0.95   0.035      ≤0.035      0.35-0.70 0.40-0.70 0.15-0.25
 Carbodur 20 NiCrMoS 2-2       20 NiCrMoS 2-2       1.6526     0.17-0.23    ≤0.40    0.65-0.95   0.035    0.020-0.040   0.35-0.70 0.40-0.70 0.15-0.25
 Carbodur 20 NiMoCrS 6-5       20 NiMoCrS 6-5       1.6757     0.17-0.23   0.15-0.40 0.60-0.90   0.035    0.020-0.035   0.30-0.50 1.40-1.80 0.40-0.50


 Carbodur 17 CrNi 6-6          17 CrNi 6-6          1.5918     0.14-0.20    ≤0.40    0.50-0.90   0.035       ≤0.035     1.40-1.70 1.40-1.70      –
 Carbodur 18 CrNi 8            18 CrNi8             1.5920     0.15-0.20   0.15-0.40 0.40-0.60   0.035       ≤0.035     1.80-2.10 1.80-2.10      –


 Carbodur 18 CrNiMo 7-6        18 CrNiMo 7-6        1.6587     0.15-0.21    ≤0.40    0.50-0.90   0.035       ≤0.035     1.50-1.80 1.40-1.70 0.25-0.35


 Carbodur 15 NiCr 13           15 NiCr 13           1.5752     0.14-0.20    ≤0.40    0.40-0.70   0.035       ≤0.035     0.60-0.90 3,00-3,50      –


Table 2: Overview of grades and chemical composition of the steels



Table 2 contains an overview of
the most common case-hardening
steels that, with the exception of
the 18 CrNi 8 and 20 NiMoCr 6-5
steels, are included in standard
DIN EN 10 084, together with the
chemical composition of the
case-hardening steels.




 44
                                                                                                      Technical information




Permissible deviations between check analysis and melt analysis
                                                                                                 1) ± means that, for a given melt, either
  Element                Maximum              Permissible deviations of the check analysis1)        the upper or the lower limit of the
                    permissible content                      from the limits                        range given for the melt analysis in
                                                                                                    Table 2 may be exceeded, but not both
                    in the melt analysis         for the melt analysis to DIN EN 10084
                                                                                                    at once.
     C                      ≤0.31                                 ±0.02
                                                                                                 2) For steels with a range of 0.020 bis
     Si                     ≤0.40                                 +0.03                             0.040% sulphur according to the melt
    Mn                      ≤1.00                                 ±0.04                             analysis, the deviation from the limit
                                                                                                    is ±0.005%.
                            >1.00≤1.40                            ±0.05
     P                      ≤0.035                                ±0.005
     S                      ≤0.040                                +0.0052)
     Cr                     ≤1.80                                 ±0.05
    Mo                      ≤0.30                                 ±0.03
                            >0.30≤0.50                            ±0.04
     Ni                     ≤2.00                                 ±0.03
                            >2.00≤3.50                            ±0.07


Comparison of international standards
      Carbodur                Material No.             Code name             Standardised in        USA                      Japan
                                                    to DIN EN 10084                               SAE/ASTM                    JIS

 Carbodur C 15 E                     1.1141       C 15 E                     DIN EN 10084            1015                    S 15

 Carbodur C 15 R                     1.1140       C 15 R                     DIN EN 10084              –                       –

 Carbodur 17 Cr 3                    1.7016       17 Cr 3                    DIN EN 10084              –                       –

 Carbodur 16 MnCr 5                  1.7131       16 MnCr 5                  DIN EN 10084            5115                      –

 Carbodur 16 MnCrS 5                 1.7139       16 MnCrS 5                 DIN EN 10084              –                       –

 Carbodur 20 MnCr 5                  1.7147       20 MnCr 5                  DIN EN 10084            5120                SMnC 420 H

 Carbodur 20 MnCrS 5                 1.7149       20 MnCrS 5                 DIN EN 10084              –                       –

 Carbodur 20 MoCr 4                  1.7321       20 MoCr 4                  DIN EN 10084              –                       –

 Carbodur 20 MoCrS 4                 1.7323       20 MoCrS 4                 DIN EN 10084              –                       –

 Carbodur 22 CrMoS 3-5               1.7333       22 CrMoS 3-5               DIN EN 10084              –                       –

 Carbodur 20 NiCrMo 2-2              1.6523       20 NiCrMo 2-2              DIN EN 10084            8620                SNCM 220 (H)

 Carbodur 20 NiCrMoS 2-2             1.6526       20 NiCrMoS 2-2             DIN EN 10084              –                       –

 Carbodur 20 NiCrMoS 6-5             1.6757       20 NiCrMoS 6-5                   –                   –                       –

 Carbodur 17 CrNi 6-6                1.5918       17 CrNi 6-6                DIN EN 10084              –                       –

 Carbodur 18 CrNi 8                  1.5920       18 CrNi 8                        –                   –                       –

 Carbodur 18 CrNiMo 7-6              1.6587       18 CrNiMo 7-6              DIN EN 10084              –                       –

 Carbodur 15 NiCr 13                 1.5752       15 NiCr 13                 DIN EN 10084      3310 / 3415 / 9314         SNC 815 (H)




                                                                                                                                        45
Forms supplied

Product        Dimensions                                     Tolerances                         Lengths/        End              As-supplied   Surface finish
                                                                                                 weights         condition        condition
                                       Dia. or edge length          Lengths      Straightness
Bar steel      55 – 250 mm dia.        DIN 1013                     Subject to   ≤ 80 mm:        4.0 – 10 m, Hot-sawn             Untreated      Rough-peeled finish
and round                                                           purchase     4.0 mm/m        other lengths or hot abrasi-                    available for 52 -
                                       > 200 mm dia. standard in-                                                               Cold-sheara-
billets for                                                         order                        on request    ve-cut                            240 mm
                                       company tolerance, closer                 > 80 mm:                                       ble
tubemaking                                                                                                                                       Max. permissible
rolled                                 tolerance on request         Special:*)   2.5 mm/m                        Special:*)
                                                                                                                                Cold-sawable surface defect dep-
                                                                    ≤ +100/-0                                    Cold-sawn,
                                                                                                                 cold abrasive- Normalized       ths:
               Sharp-edged             DIN 1014                                  < 1000 mm2:                     cut                             Round: 1% max. of
               50 – 103 mm square                                                4.0 mm/m                                       Treated to
                                                                                                                                                 dia. + 0.05 mm
                                                                                                                                ferrite-pearlite
                                                                                 > 1000 mm2:                                    structure        Square: 1% max. of
               Flat:                   DIN 1017                                  2.5 mm/m
                                       up to 150 mm width and                                                                                    edge length
               Width: 80 – 510 mm                                                                                               Treated to
               Thickness:              60 mm thickness;                          Special:*)                                     hardness         Flat: 1.5% max. of
               25 – 160 mm             over 150 mm width                         Specially                                      range            width, 2.0% max. of
               Width/thickness         standard in-company tole-                 straightened                                                    thickness
               ratio 10:1 max          rance                                                                                    Soft-annealed
                                                                                                                                                 Special:*)
               Width:                                                                                                           Spheroidize- Smaller surface
Sheet bars                             Tolerance on request                                                                                      defect depth on
               25 – 160 mm                                                                                                      annealed
rolled with                                                                                                                                      request
bulbous nar-   Thickness:                                                                                                       Stress-relie-
row face       80 – 550 mm                                                                                                      ved
                                                                                                                                  Quenched
Semis          50 – 320 mm square,     < 210 mm +/- 2%                           Standard:                       ≤ 210 mm                      Edge radius:
                                                                                                                                  and tempered
rolled         rising in 1 mm incre-   > 210 mm +/- 3%                           6 mm/m                          square:
               ments                                                                                             hot-sawn                      < 210 mm - 12-18%
                                       of edge length
                                                                                 Special:*)                      or hot abrasi-                of edge length
                                       Special:*)                                4 mm/m                          ve-cut                         > 210 mm: without
                                        ≤ 100 mm +/- 1%
                                                                                                                 > 210 mm                       defined edge radius
                                       of edge length
                                                                                                                 square:                        Max. perm. surface
                                       > 100 mm – 210 mm                                                         hot-sheared                    defect depth:
                                       +/- 1.5% of edge length                                                   Special:*)                     ≤ 140 mm sq.
                                                                                                                 Cold abrasive-                 0.3 mm max.
                                                                                                                 cut, cold-sawn
                                                                                                                                                > 140 - 200 mm sq.
                                                                                                                                                0.6 mm max.
                                                                                                                                                > 200 mm sq.
                                                                                                                                                visible defects elimi-
                                                                                                                                                nated

Bar steel      65 – 750 mm dia.        DIN 7527                                  Semis:          Lengths as      Hot abrasive-                  Special:*)
and semis                                                                        as-forged       a function of   cut or cold-
               265 – 650 mm                                                      straightness    dimensions                                     - Rough-peeled
forged                                                                                                           sawn
               square                                                                            and heat-                                      - Turned
                                                                                 Bar steel:                      Special:*)                     - Milled
               flat: on request                                                                  treatment
                                                                                 to DIN within                   Cold abrasive-
                                                                                                 condition
                                                                                 the tolerance                   cut
                                                                                                 on request
                                                                                 limit




Bright steel                                                                     As-peeled       3 - 10 m, on    Hot-sawn/hot                   Technically crack-free
                                                                                 straightness    request 30 m    abrasive-cut                   condition e.g. eddy-
peeled         52 – 400 mm dia.        ISA Tol. 11 or comparable                 ≤ 2 mm/m,       max. as a                                      current tested or
                                       tolerance                                 1 mm/m or       function of     Special:*)
                                                                                                                                                comparable tech-
                                                                                 closer as a     dia. and        Cold-sawn/
peeled and     52 – 300 mm dia.        ISA Tol. 11 or comparable                                                                                nique, defined depth
                                                                                 function of     max. bar        abrasive-cut
polished                               tolerance                                                                                                of roughness and sui-
                                                                                 dimensions      dead weight     Dimensions 50                  table packaging by
                                                                                 on request      of 7 t          - 105 mm with                  special arrangement
                                                                                                                 round chamfer
                                                                                                                 30° or 45°,
                                                                                                                 chamfer width
ground         52 – 100 mm dia.        ISA-Tol. 8 or comparable                                  3–8m            approx. 5 -12
                                       tolerance                                                                 mm, other
                                                                                                                 widths by ar-
                                                                                                                 rangement


As-cast        on request
ingots/c.c.
blooms
Open-die       Forgings forged to
forgings       shape on request
               (drawing)

*) Special finishes subject to further inquiry (partly dependent on quality, dimensions and condition)




 46
Hardness comparison table


                   Tensile strength, Brinell,
               Vickers and Rockwell hardness
 Tensile       Brinell hardness    Vickers            Rockwell hardness                 Tensile        Brinell hardness           Vickers                 Rockwell hardness
strength   Ball inden-            hardness                                             strength        Ball                      hardness
   Rm      tation mm                                                                      Rm       indentation
 N/mm2           d          HB      HV         HRB          HRC           HR 30 N       N/mm2         mm d          HB              HV             HRB          HRC           HR 30 N
 255          6.63        76.0       80          –           –              –          2030              2.54      (580)           610                –         55.7           73.7
 270          6.45        80.7       85        41.0          –              –          2070              2.52      (589)           620                –         56.3           74.2
 285          6.30        85.5       90        48.0          –              –          2105              2.51      (599)           630                –         56.8           74.6
 305          6.16        90.2       95        52.0          –              –          2145              2.49      (608)           640                –         57.3           75.1
 320          6.01        95.0      100        56.2          –              –          2180              2.47      (618)           650                –         57.8           75.5
 335          5.90        99.8      105          –           –              –            –                 –        –              660                –         58.3           75.9
 350          5.75       105        110        62.3          –              –            –                 –        –              670                –         58.8           76.4
 370          5.65       109        115          –           –              –            –                 –        –              680                –         59.2           76.8
 385          5.54       114        120        66.7          –              –            –                 –        –              690                –         59.7           77.2
 400          5.43       119        125          –           –              –            –                 –        –              700                –         60.1           77.6
 415          5.33       124        130        71.2          –              –            –                 –        –              720                –         61.0           78.4
 430          5.26       128        135          –           –              –            –                 –        –              740                –         61.8           79.1
 450          5.16       133        140        75.0          –              –            –                 –        –              760                –         62.5           79.7
 465          5.08       138        145          –           –              –            –                 –        –              780                –         63.3           80.4
 480          4.99       143        150        78.7          –              –            –                 –        –              800                –         64.0           81.1
 495          4.93       147        155          –           –              –            –                 –        –              820                –         64.7           81.7
 510          4.85       152        160        81.7          –              –            –                 –        –              840                –         65.3           82.2
 530          4.79       156        165          –           –              –            –                 –        –              860                –         65.9           82.7
 545          4.71       162        170        85.0          –              –            –                 –        –              880                –         66.4           83.1
 560          4.66       166        175          –           –              –            –                 –        –              900                –         67.0           83.6
 575          4.59       171        180        87.1          –              –            –                 –        –              920                –         67.5           84.0
 595          4.53       176        185          –           –              –            –                 –        –              940                –         68.0           84.4
 610          4.47       181        190        89.5          –              –
 625          4.43       185        195          –           –              –
                                                                                    Conversions of hardness values using this conversion table are only approximate.
 640          4.37       190        200        91.5          –              –
 660          4.32       195        205        92.5          –              –       See DIN 50 150, December 1976.
 675          4.27       199        210        93.5          –              –
 690          4.22       204        215        94.0          –              –
 705          4.18       209        220        95.0          –              –
 720          4.13       214        225        96.0          –              –
 740          4.08       219        230        96.7          –              –
 755          4.05       223        235          –           –              –
 770          4.01       228        240        98.1         20.3           41.7
 785          3.97       233        245          –          21.3           42.5
 800          3.92       238        250        99.5         22.2           43.4
 820          3.89       242        255          –          23.1           44.2
 835          3.86       247        260      (101)          24.0           45.0
 850          3.82       252        265          –          24.8           45.7
 865          3.78       257        270      (102)          25.6           46.4
 880          3.75       261        275          –          26.4           47.2
 900          3.72       266        280      (104)          27.1           47.8
 915          3.69       271        285          –          27.8           48.4
 930          3.66       276        290      (105)          28.5           49.0
 950          3.63       280        295          –          29.2           49.7
 965          3.60       285        300          –          29.8           50.2
 995          3.54       295        310          –          31.0           51.3
1030          3.49       304        320          –          32.2           52.3
1060          3.43       314        330          –          33.3           53.6
1095          3.39       323        340          –          34.4           54.4
1125          3.34       333        350          –          35.5           55.4
1155          3.29       342        360          –          36.6           56.4
1190          3.25       352        370          –          37.7           57.4
1220          3.21       361        380          –          38.8           58.4
1255          3.17       371        390          –          39.8           59.3
1290          3.13       380        400          –          40.8           60.2
                                                                                     Tensile strength                      N/mm2                                          Rm
1320          3.09       390        410          –          41.8           61.1
1350          3.06       399        420          –          42.7           61.9
                                                                                     Brinell hardness1)                    Diameter of the                                d
1385          3.02       409        430          –          43.6           62.7      1)
                                                                                        Calculated from:                   ball indentation in mm
1420          2.99       418        440          –          44.5           63.5
                                                                                        HB = 0.95 · HV
1455          2.95       428        450          –          45.3           64.3
1485          2.92       437        460          –          46.1           64.9
1520          2.89       447        470          –          46.9           65.7                                                             0.102 · 2 F
                                                                                     (0.102 F/D2 = 30)                     Hardness                                       HB
1555          2.86      (456)       480          –          47.7           66.4      D = 10                                value =       π D (D – √D2 – d2)
1595          2.83      (466)       490          –          48.4           67.1
1630          2.81      (475)       500          –          49.1           67.7      Vickers hardness                      Diamond pyramid                                HV
1665          2.78      (485)       510          –          49.8           68.3                                            Test forces ≥ 50 N
1700          2.75      (494)       520          –          50.5           69.0
1740          2.73      (504)       530          –          51.1           69.5      Rockwell hardness                     Ball 1.588 mm (1/16“)                          HRB
1775          2.70      (513)       540          –          51.7           70.0                                            Total test force = 98 N
1810          2.68      (523)       550          –          52.3           70.5
1845          2.66      (532)       560          –          53.0           71.2                                            Diamond cone                                   HRC
1880          2.63      (542)       570          –          53.6           71.7                                            Total test force = 1471 N
1920          2.60      (551)       580          –          54.1           72.1
1955          2.59      (561)       590          –          54.7           72.7                                            Diamond cone
1995          2.57      (570)       600          –          55.2           73.2                                            Total test force = 294 N                       HR 30 N


                                                                                                                                                                                  47
Temperature Comparison


                                                           Chart

                                    °C                     °F                            K

X = particular                 K    X– 273                 9 /5 (X–273) + 32             X

    measured                   °C   X                      9 /5 X + 32                   X + 273

    temperature                °F   5 /9 (X–32)            X                             5 /9 (X–32) + 273

         °C             °F                 K        °C             °F            K                 °C          °F         K
      –273,15     –459,67                  0,00   380,00         716,00         653,15         910,00        1670,00   1183,15
      –270,00     –454,00                  3,15   390,00         743,00         663,15         920,00        1688,00   1193,15
      –200,00     –328,00                 73,15   400,00         752,00         673,15         930,00        1706,00   1203,15
      –150,00     –238,00                123,15   410,00         770,00         683,15         940,00        1724,00   1213,15
      –100,00     –148,00                173,15   420,00         788,00         693,15         950,00        1742,00   1223,15
      – 90,00     –130,00                183,15   430,00         806,00         703,15         960,00        1760,00   1233,15
      – 80,00     –112,00                193,15   440,00         824,00         713,15         970,00        1778,00   1243,15
      – 70,00     – 94,00                203,15   450,00         842,00         723,15         980,00        1796,00   1253,15
      – 60,00     – 76,00                213,15   460,00         860,00         733,15         990,00        1814,00   1263,15
      – 50,00     – 58,00                223,15   470,00         878,00         743,15        1000,00        1832,00   1273,15
      – 40,00     – 40,00                233,15   480,00         896,00         753,15        1010,00        1850,00   1283,15
      – 30,00     – 22,00                243,15   490,00         914,00         763,15        1020,00        1868,00   1393,15
      – 20,00     –     4,00             253,15   500,00         932,00         773,15        1030,00        1886,00   1303,15
      – 17,78           0,00             255,37   510,00         950,00         783,15        1040,00        1904,00   1313,15
      – 10,00          14,00             263,15   520,00         968,00         793,15        1050,00        1922,00   1323,15
         0,00          32,00             273,15   530,00         986,00         803,15        1060,00        1940,00   1333,15
        10,00          50,00             283,15   540,00        1004,00         813,15        1070,00        1958,00   1343,15
        20,00          68,00             293,15   550,00        1022,00         823,15        1080,00        1976,00   1353,15
        30,00          86,00             303,15   560,00        1040,00         833,15        1090,00        1994,00   1363,15
        40,00         104,00             313,15   570,00        1058,00         843,15        1100,00        2012,00   1373,15
        50,00         122,00             323,15   580,00        1076,00         853,15        1110,00        2030,00   1383,15
        60,00         140,00             333,15   590,00        1094,00         863,15        1120,00        2048,00   1393,15
        70,00         158,00             343,15   600,00        1112,00         873,15        1130,00        2066,00   1403,15
        80,00         176,00             353,15   610,00        1130,00         883,15        1140,00        2084,00   1413,15
        90,00         194,00             363,15   620,00        1148,00         893,15        1150,00        2102,00   1423,15
       100,00         212,00             373,15   630,00        1166,00         903,15        1160,00        2120,00   1433,15
       110,00         230,00             383,15   640,00        1184,00         913,15        1170,00        2138,00   1443,15
       120,00         248,00             393,15   650,00        1202,00         923,15        1180,00        2156,00   1453,15
       130,00         266,00             403,15   660,00        1220,00         933,15        1190,00        2174,00   1463,15
       140,00         284,00             413,15   670,00        1238,00         943,15        1200,00        2192,00   1473,15
       150,00         302,00             423,15   680,00        1256,00         953,15        1210,00        2210,00   1483,15
       160,00         320,00             433,15   690,00        1274,00         963,15        1220,00        2228,00   1493,15
       170,00         338,00             443,15   700,00        1292,00         973,15        1230,00        2246,00   1503,15
       180,00         356,00             453,15   710,00        1310,00         983,15        1240,00        2264,00   1513,15
       190,00         374,00             463,15   720,00        1328,00         993,15        1250,00        2282,00   1523,15
       200,00         392,00             473,15   730,00        1346,00        1003,15        1260,00        2300,00   1533,15
       210,00         410,00             483,15   740,00        1364,00        1013,15        1270,00        2318,00   1543,15
       220,00         428,00             493,15   750,00        1382,00        1023,15        1280,00        2336,00   1553,15
       230,00         446,00             503,15   760,00        1400,00        1033,15        1290,00        2354,00   1563,15
       240,00         464,00             513,15   770,00        1418,00        1043,15        1300,00        2372,00   1573,15
       250,00         482,00             523,15   780,00        1436,00        1053,15        1310,00        2390,00   1583,15
       260,00         500,00             533,15   790,00        1454,00        1063,15        1320,00        2408,00   1593,15
       270,00         518,00             543,15   800,00        1472,00        1073,15        1330,00        2426,00   1603,15
       280,00         536,00             553,15   810,00        1490,00        1083,15        1340,00        2444,00   1613,15
       290,00         554,00             563,15   820,00        1508,00        1093,15        1350,00        2462,00   1623,15
       300,00         572,00             573,15   830,00        1526,00        1103,15        1360,00        2480,00   1633,15
       310,00         590,00             583,15   840,00        1544,00        1113,15        1370,00        2498,00   1643,15
       320,00         608,00             593,15   850,00        1562,00        1123,15        1380,00        2516,00   1653,15
       330,00         626,00             603,15   860,00        1580,00        1133,15        1390,00        2234,00   1663,15
       340,00         644,00             613,15   870,00        1598,00        1143,15        1400,00        2552,00   1673,15
       350,00         662,00             623,15   880,00        1616,00        1153,15        1500,00        2732,00   1783,15
       360,00         680,00             633,15   890,00        1634,00        1163,15        2000,00        3632,00   2273,15
       370,00         698,00             643,15   900,00        1652,00        1173,15        2500,00        4532,00   2773,15



 48
               Photos
     Page      Source                  Object/Motif

     Cover     Bavaria                 Gear wheel
     03        Lohmann + Stolterfoth   Planetary gear
     04        Steinmetz               Team meeting
      4– 5     Sauter, Bachmann        Spiral bevel gears
      4        Sauter, Bachmann        Set of gears
      5        Sauter, Bachmann        Precision worm
               Company photo           Micrograph
      6– 7     ATA-GEARS               Hardening of a ring gear
      7        Company photo           Steel bars
      7        Steinmetz               Chips
      8        CarboTech               Cutting drum
               Bavaria                 Hydroelectric power station
      8– 9     Lohmann + Stolterfoth   Planetary gear
      8        ATA-GEARS               Spiral bevel gears
      9        Image                   Drilling rig
               Bavaria                 Wind turbine generators
               Schreiber/Flender       Gears for wind turbine generator
               Frese                   Gear wheel
     10        Schuster                Airbus
               Bavaria                 Formula 1 racecar
     10 – 11   ATA-GEARS               Ring gear with pinion
     10        Company photo/Flender   Set of gears




     11        DAF                     XF95 truck
               VW                      VW Golf
               Imagine                 Oil tanker
               MAAG Gear               Marine gear
               Company photo           Cable car
     12        Company photo           Printing press
               Lohmann + Stolterfoth   Parabolic reflector
     12 – 13   Company photo/Flender   Set of gears
     12        Lohmann + Stolterfoth   Gear wheels for combing cylinder gear
     13        Company photo           Crane truck
               Company photo           Wheel loader
               Imagine                 Ariane rocket
               Company photo/Flender   Gear detail
     14        Steinmetz               Sawing of disks
               Steinmetz               Disks with and without drilled hole
               Steinmetz               Steel bars
     15        Lohmann + Stolterfoth   Ground gear wheels
     16        Company photo           Electric arc furnace
     17        Company photo           Continuous casting plant
               Company photo           ESR plant
     18        Company photo           Forged steel bars
               Company photo           Peeling of steel bars
     18 – 19   Company photo           Forging of steel bars
               Company photo           Sawing of steel bars
               Steinmetz               Disks with drilled hole
     36        Sauter, Bachmann        Spiral bevel gears
     40        Lohmann + Stolterfoth   Case hardening of a large wheel
     42        Lohmann + Stolterfoth   Ground gear wheels
               ATA-GEARS               Spiral bevel gears
     43        Frese                   Gear wheel
     44        Lohmann + Stolterfoth   Gear wheels for combing cylinder gear
     48 – 49   Lohmann + Stolterfoth   Planetary gear



50
General note (liability)

All statements regarding the properties

or utilisation of the materials or products

mentioned are for the purposes of

description only. Guarantees regarding

the existence of certain properties or a

certain utilisation are only ever valid if

agreed upon in writing.




                                              51
  CARBODUR
   CARBODUR
CARBODUR
 CARBODUR               CARBODUR
                         CARBODUR
                                             Case-hardening steels

 • Sales - Case-hardening steels
   Tel. (+49) 23 02/29 43 46 · Telefax (+49) 23 02/29 46 87
   E-mail: ressing@ewkgmbh.de

 • Quality Department
   Tel. (+49) 23 02/29 40 20 · Telefax (+49) 23 02/29 44 36
   Tel. (+49) 21 51/83 20 46 · Telefax (+49) 21 51/83 41 56




                                                                                              7/99Ec




     EDELSTAHL WITTEN-KREFELD GMBH
 Auestrasse 4, D-58452 Witten · Tel. (+49) 23 02 / 29 43 07 · Telefax (+49) 2302 / 29 43 08
    E-mail: dr.sobottka@ewk.thyssen.com · Internet: www.edelstahl-witten-krefeld.de

								
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