Thin strip lap welding method of lap welding machine of cold rolling recoiling unit

Abstract

The invention discloses a method for achieving stitch welding of a thin strip by means of a lap welder of a cold rolling rewinding unit. The method comprises the steps that during tail flicking of an online steel coil with the thickness being a, a strip tail is conveyed to the place 350 mm-400 mm away from the edge of a lower clamp at an inlet of the welder and does not enter a shear blade; during coil feeding of a next steel coil with the thickness being b, a strip head passes through the strip tail of the online steel coil, and the strip head is conveyed through a lower shear blade of the welder and enters a lower clamp at an outlet of the welder by about 350 mm-400 mm; and after the strip head and the strip tail are aligned, built-in scissors of the welder are used for shearing the strip head and the strip tail for shear operation, the thickness of a front steel plate and a rear steel plate is changed into a+b after shearing is finished, and lap welding is carried out according to the parameter that the thickness of the steel strip is a+b after overlapping. The method has the beneficial effects that stable welding production of the ultra-thin strip is achieved; the need of cold rolling rewinding production is met; the rewelding time is shortened; production efficiency is improved; the rewelding rate is reduced to 2% from original 83%; and the strip breakage rate is also reduced to 0.

Description

technical field [0001] The invention relates to the field of iron and steel rolling production, in particular to a method for lap welding thin strips with a thickness of less than 0.5 mm by lap welding machines in cold rolling plants. Background technique [0002] At present, in the production of cold rolling and recoiling units, when welding thin strip steel with a thickness of less than 0.5mm, it is difficult to ensure the quality of the weld seam due to the thin strip material, and welding according to the process parameters is easy to produce virtual welding, desoldering, and penetration. Welding, the strength of the weld seam cannot be guaranteed, and the weld seam is easily broken when it passes through the process section and the tension is built, and the forward production of the recoiling line cannot be guaranteed. With the transition plate welding, a steel plate of about 0.8mm×350mm is added in the middle of the lap welding strip for transition welding. Although th...

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Problems solved by technology

[0003] The purpose of the present invention is to provide a kind of lap-welding thin strip below 0.5mm thickness, which is economical and feasible, so as to solve the problem that the existing heavy coil welding machine cannot effectively weld the thin strip below 0.5mm thickness, and improve the unit production. Efficiency, yield and quality of cold rolling and recoiler lap welding machine thin strip lap welding method

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