Non-oriented electrical steel head and tail flash welding technique

Abstract

The invention discloses a flash welding technological method for the head and the tail of non-oriented electrical steel used in cold-rolling pickling line and tandem cold mill to enhance the quality of the weld joint. The technological method comprises the following steps: a low-carbon steel material with the same thickness and width is inserted between a front roll of non-oriented electric steel and a back roll of non-oriented electric steel; the head of the low-carbon steel material is welded with the tail of the back roll of non-oriented electric steel and the tail of low-carbon steel material is welded with the head of the back roll of the non-oriented electric steel. The flash welding technological method for the head and the tail of a non-oriented electrical steel used in cold-rolling pickling line and tandem cold mill has the advantages that due to good plasticity and toughness, the quality of the weld joint of the non-oriented steel after welding is greatly enhanced without lap joint and is qualified in the on-site cupping test, avoiding thrust belt of the joint; the weld joint can not only pass through the acid, but also normally through the miller for rolling, without need of reducing pressure, tension or speed, therefore, the technological method is particularly suitable for popularization in band steel manufacturing of cold-rolling pickling line and tandem cold mill.

Description

technical field [0001] The invention relates to a welding process operation method, in particular to a process method for head-to-tail flash welding of non-oriented electrical steel used in the production of a combined cold-rolling-acid-rolling unit. Background technique [0002] At present, in the modern large-scale cold-rolling production process, the hot-rolled steel strip needs to be welded by a welding machine to form a whole strip before pickling, so as to ensure the continuous production of pickling and rolling. Connections are made using the fast flash soldering process. The weld at the joint of the steel strip is the biggest weak link in the cold rolling production process. When the poor quality weld passes through the rolling mill, measures such as raising the roll gap, reducing pressure and tension, and reducing the rolling speed must be taken. The cold-rolling-acid-rolling unit has higher requirements on the welding quality of the steel strip head and tail. It i...

AI Technical Summary

Problems solved by technology

Silicon is one of the main elements that can significantly increase the cold hardening index. Under the condition of 0.2% to 1.5%wt of silicon, the hardness of the weld seam will greatly increase and become brittle when it is deformed by high-speed cold rolling, which will deteriorate the weld. Seam performance, resulting in electrical steel welds are more likely to break

[0003] However, in the prior art, for the head-to-tail welding of the strip steel in the combined cold-rolling-acid-rolling unit, a laser welding process is used to improve the mechanical properties of the weld seam so that it is basically consistent with the base metal and reduce broken strips, but the cost is high , high maintenance technical requirements, generally used in high-silicon oriented silicon steel production lines containing more than 1.5% silicon

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