DE2018921A1 - Welding of endless cold rolled steel strip belts - Google Patents

Abstract

Joining of cold rolled steel strips to form endless strips consists of spreading out the edges to be welded together by a cold forging operation, welding together the two edges under conditions which minimize heat flow away from the weld area, followed by flattening of the weld area by rolling. The mechanical props. of the weld area are equal to that of the remaining material. The strip is used for moving pavements etc.

Description

Method of making endless steel belts ~ ============================= ~ ============= ~ = The invention relates to a method for producing endless steel strips from cold-rolled Sheet metal and a device to restrict the flow of heat to the weld seam area the abutting metal sheets.

Endless strips of cold-rolled sheet steel are for example used in the manufacture of flooring membranes.

When joining cold-rolled sheets along their edges Welding results in the difficulty that the heated zone during welding loses the mechanical properties achieved during work hardening and through the weld penetration results in a reduction in the material thickness.

The object of the present invention is therefore to provide cold-rolled Steel strips along their edges with one another without penetration while maintaining the to weld properties achieved by the work hardening of the strips.

This object is achieved according to the invention in that the welding edges of the ribbons upset, restricting the heat flow to the area of the Seam welded and solidified by rolling the upsetting. Appropriately is rolled down in the direction of the weld seam after descaling.

The device for restricting the flow of heat to the weld seam area is characterized by the fact that the abutting, upset welding edges the steel strips on a block made of a material that conducts heat well in a recess arranged and by further blocks of the same material on the steel strips are firmly clamped on both sides of the seam to be formed.

The present invention will be explained in more detail with the aid of the accompanying drawing Fig. 1 shows the change in dimension of the steel band edge when diving.

Fig. 2 shows an example embodiment of the device for Limitation of the heat flow to the weld seam area.

Since the yield point of cold-rolled steel strips is llo to 2 12o mm, the required diving forces are very high. The one resulting from upsetting Upsetting width b and upsetting depth t are for a certain sheet thickness of the upsetting height h dependent. The individual sizes are shown in FIGS. 1 for a steel strip 2. In of the table below are for a thickness of the band 2 of 1 mm those for different Upsetting heights h achievable upsetting widths b listed.

TABLE Compression height h Compression width b 0.7 mm 1.6 to 1.75 mm 1.0 mm 1.5 to 1.8 mm 1.5 mm 2, o to 2.4 mm The steel strips, for example from a Steel of material number 4301, after upsetting their welding edges a plate 1, which may for example consist of steel, arranged so that the Weld edges abut one another along plane 3, as shown in FIG. In the plate 1 is a block 5 made of a material that conducts heat well, for example Copper, let in, which has a recess 6 in which the adjacent, upset welding edges of the steel strips 2 come to rest. This copper block 5 provides, together with two others, on the steel belts 2 on both sides of the trainees Welded seam arranged copper blocks 4 for the fact that the generated during welding The heat flow to the seam area remains limited, since that flows off into the ligaments Heat is dissipated immediately through the copper blocks. The top copper blocks are 4 pushed as close as possible to the welding edges, whereby the limits by the initial upsetting and the space required for welding are specified are.

Because of the thermal stresses that occur during welding, the Belts 2 must be firmly clamped. This clamping device is not shown in FIG. The clamping forces, however, expediently act on the copper blocks 4, so that the Steel strips 2 in good contact with the copper blocks 4 for favorable heat dissipation stand.

After the steel strips are arranged in the manner described are welded together. Because there is enough weldable due to the upsetting If material is available, the welding is done according to the Argonarc method expediently before. Due to the heat dissipation through the copper blocks 4 and 5 the heat affected zone kept as small as possible.

After welding, the blocks 4 are removed and the weld seam freed from the resulting scale and the tarnish color by the action of stain. The weld seam is then strengthened by rolling it in the direction of the seam. If necessary, the weld seam is still to the desired after rolling Final thickness sanded off.

Keep the endless steel belts made by this process advantageously the mechanical properties of the cold-rolled strips to the Connection points essentially at. Strength tests have shown that the sweat factor is more than 80%.

Claims (3)

PATENT CLAIMS 0 Process for the production of endless steel strips from cold-rolled Sheet metal, characterized in that the welding edges of the strips are upset, under Limitation of the heat flow to the area of the seam welded and by rolling solidified by upsetting. 2. The method according to claim 1, characterized in that according to the Descaling is rolled off in the direction of the weld seam. 3. Device for restricting the flow of heat to the weld seam area when carrying out the method according to claim 1 or 2, characterized in that that the abutting, upset welding edges of the steel strips (2) on one Block (5) made of a material with good thermal conductivity and arranged in a recess (6) by further blocks (4) of the same material on the steel strips (2) to both Sides of the seam to be formed (3) are firmly clamped. Blank page