Introduction Manufacturing Process by ufq12259

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									Algoma Welded Shapes
Introduction                                                  Manufacturing Process
          Algoma Steel Inc., located in Sault Ste. Marie,               Algoma Welded Shapes are made from high
Ontario, is a fully integrated mill producing in excess of    quality steel plate rolled on Algoma’s 166” Plate Mill.
2.2. million tons of steel per year. There are three main     This mill is capable of rolling plate up to 3860mm (152”)
products: sheet, plate, and welded shapes. Algoma’s           wide and up to 70mm (2.75”) thick and in mill rolled
metallurgical lab has received certification from the         lengths up to 24400mm (80’). An innovative
American Association of Lab Accreditations (A2LA).            computerized process control system results in
The sheet/plate and welded shapes complexes are               products with better dimensional control and
ISO 9002 certified. Algoma’s Welded Beam Division             mechanical properties which are more consistent and
started operations in 1965 and is located just a short        reproducible.
distance from the main mill.                                            As the plate enters the Welded Beam Division
          Algoma Steel produces three basic types of          plant, it passes through a blast cleaning machine which
welded shapes: a regular catalogue range of symmetrical       scours mill scale from all surfaces. This is a prerequisite
structural sections (WWF) with depths from 350mm(14”)         for the high-speed flame cutting and welding used in
to 1800mm (71”), a regular catalogue range of unsymmetrical   the manufacturing process.
sections (WRF) with depths from 1000mm (39”) to                         The plates are then cut by the oxypropane
1800mm (71”), and a range of Welded Special Sections          process into strips which will become the webs and
(WWS) up to 2340mm (92”) deep.                                flanges of various sections. Two plates, up to 3050mm
          WWS Sections can be produced to special             (10’) wide and 24400mm (80’) long can be handled
profiles with varying degrees of symmetry and camber,         simultaneously.
hybrid flange and web steels and special testing                        Flame cut edges are carefully examined to make
requirements, in accordance with customer specifications.     sure that surfaces are cut true and free from oxide. Cut
Typical applications include crane and bridge girders.        flanges and webs are sorted and accumulated into
                                                              assembly batches.
                                                                        All three plates for a particular section are
                                                              loaded horizontally, side by side, on the input conveyor.
                                                              The web is positioned in the middle, between the top
                                                              and bottom flanges.
                                                                        Flange plates are rotated into the vertical
         Contacts:                                            position and held against the edges of the web.
         Vincent M. Sguigna                                   Vertically adjustable rollers support the flanges so they
               Phone: 705 945 3965                            are centred on the web. The underside of the web forms
                                                              the datum level for the entire assembly. The component
                                                              plates are then inserted into the assembly machine and
                Toll Free:                                    welded.
                1 877 855 5595                                          The assembly machine is similar to a large vise
                                                              with the opposing faces fitted with large drive rollers.
                Fax: 705 945 4316
                                                              Applying powerful horizontal fitting pressure, the drive
         e-mail: vsguigna@algoma.com                          rollers propel the assembly at uniform speeds under the
                                                              welding heads. Adjustable rollers support the plates
                                                              such that no tack welds are necessary to keep them
                                                              properly positioned. At all times prior to welding, the
                                                              plates are unrestrained longitudinally. The equipment
                                                              is also capable of processing asymmetrical or
                                                              nonprismatic members when required.
                                                                        As the half welded assembly clears the
                                                              machine, it is turned over and placed on the conveyor to
                                                              the second welding station. There, the same welding
                                                              process is repeated on the other side of the web.
                                                                        A 3-torch cut off machine cuts the completed
                                                              assemblies to the ordered length. Samples are removed
                                                              from this surplus material for macro examination and
                                                              tensile testing of the welded joint in accordance with
                                                              the requirements of CSA G40.20-M94.

                                                                                                        January, 2000
Algoma Welded Shapes
Quality Control
         In the inspection area, each section is quality
checked dimensionally to verify conformance with
tolerances, and all welds are examined for correct profile
and evidence of defects. If repairs are necessary,
consumables are used to duplicate the penetration and
mechanical properties of submerged arc welds.
         The Canadian Welding Bureau was consulted at all
phases of development and has certified the plant as
meeting the requirements of C.S.A. Standard W47 Welding
Qualification Code.


Welding
         Welds are made simultaneously along both
flange-web joints in the horizontal fillet position. Two DC
arcs in tandem are used to make each weld, and into both
arc areas are fed two relatively small diameter wires,
electrically in parallel. The two wires are close enough
that they operate under common molten pool of flux, yet
far enough apart that the metal from the first arc has
frozen before the metal from the second arc is deposited
on top. This technique has several benefits:

• The first bead can be designed to give deep penetration,
  while the second can be designed to build up throat
  thickness and desired surface profile.

• The resultant weld cross-section is such that relatively
  high amperages can be used without throat cracking,
  which is occasionally encountered with deep
  penetration welds.

• It is possible to make the full range of weld sizes
  required without changing wire diameter by simply
  altering the relative position of the parallel electrodes,
  and speed of travel.

• Full penetration welds can be accommodated up to a
  maximum web thickness of 12mm (o.5”).
Algoma Welded Shapes
Manufacturing Capabilities
1 Depth            (d)       Maximum                                                  2340mm         (92”)
                             Minimum                                                   350mm         (14”)
                             2160 mm to 2340mm (85” to 92”) subject to inquiry
2 Flange Width     (b)       Maximum                                                   660mm         (26”)
                             Minimum                                                   125mm          (5”)

3 Flange Thickness (t)       Maximum                                                    70mm       (2.75”)
                             Minimum                                                    10mm      (0.375”)
4 Web Width        (h)       Minimum                                                   250mm         (10”)
                             230mm to 250mm (9” to 10”) subject to inquiry
5 Web Thickness    (w)       Maximum                                                    70mm       (2.75”)

6 Length           (L)       Maximum without splices*                                 24400mm     (80’-0”)
                             Maximum with splices**                                   30500mm    (100’-0”)

7 Camber           (•)       Maximum                                                   200mm           (8”)
8 Mass                       Maximum                                                   740kg/m   (500lb/ft)
                             740 to 900 kg/m (500 to 600 lb./ft) subject to inquiry
9 Welding                    Maximum fillet*                                            10mm      (0.375”)
                             Minimum fillet                                              6mm       (0.25”)
                             Maximum web thickness for full penetration**               12mm         (0.5”)

                             *Subject to mill limits
                             **Subject to inquiry




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