Segmental welding method for butt welding of raw material band steel joint plates of high-frequency straight welding tube

Abstract

The invention provides a segmental welding method for butt welding of raw material band steel joint plates of a high-frequency straight welding tube. The method comprises the following steps of: segmenting: dividing a welding segment and a non-welding segment according to the width of raw material belt steel; and welding: when the tail part of the last reel of raw material band steel is left after the raw material band steel is input on a welding tube production line, unreeling the next reel of raw material band steel and leading the head part of the next reel of raw material band steel, undercutting and shearing the head and the tail of the raw material band steel to be neat and aligned, and then welding the segmented welding segment, wherein the welding method of carbon dioxide gas arc welding or manual arc welding is adopted for the butt welding of the raw material band steel. The segmental welding method provided by the invention has the advantages that no welding seams or weldingflashes exist so that the phenomenon of surface scratch of a tube blank is not generated, the surface quality of a welded tube meet a standard requirement of a qualified welded tube, the first pass yield of the welded tube is improved, the service life of a roller is prolonged, continuous production can be maintained, no losses in operation time is ensured, the consumption of welding materials isdecreased by 1 / 3, meanwhile, partial electric consumption is lowered.

Description

technical field [0001] The utility model belongs to the technical field of metallurgical steel rolling, in particular to a segmented butt welding method for butt welding of raw material strips of high-frequency straight seam welded pipes. Background technique [0002] At present, the production of high-frequency straight seam welded pipe adopts the hot-rolled carbon steel finished raw material strip coil produced by the steel factory, and the welded pipe manufacturer cuts the finished raw material strip steel coil into a certain width of the raw material strip calculated according to the outer diameter and wall thickness of the welded pipe. Steel, at least 2 tons or more, is used as raw material strip steel. In order to maintain the continuous production of the production line, the front and rear two rolls of raw material strips must be welded together during production. The welding position is to be completely welded along the width of the raw material strips, and the raw m...

AI Technical Summary

Problems solved by technology

Starting from the first fine forming stand, rolling by three fine forming rolls, and finally rolling by the sizing roll group, the raw material strip and the upper and lower horizontal rolls are welded along the contact point due to the full width of the joint between the plates, such as Carbon dioxide gas shielded welding, manual arc welding and other methods will produce weld seams with weld bumps, enter the first frame of fine forming and start to the third frame of fine forming, and pass through the sizing unit of general 3-4 frames, go up The horizontal roller and the lower horizontal roller will scratch the outer surface of the tube blank along the contact point of the upper and lower horizontal rollers, so that the surface quality of the welded pipe does not meet the requirements of the welded pipe standard

[0005] 2. The weld bead caused by the welding of the full plate width of the butt joint, accelerates the wear of the roll edge through the raw material strip steel and the upper and lower horizontal roll edges;

[0006] 3. Once the welding edge of the raw material strip steel plate is poorly welded, the edge of the welded seam of the welded pipe may crack under the tension of the production process through material storage, roll forming and other processes, and may even fail to stop the crack, resulting in the weld being broken , in the production process, if the welding seam is broken, it is necessary to re-feed the lead plate, resulting in serious consequences of stopping production for several hours, and it is impossible to maintain continuous production

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