Method for cold rolling high silicon electric steel

Abstract

The invention provides a cold rolling method for high-silicon electrical steel. The method comprises conventional processes of a first cold rolling for a hot rolled plate after being treated with acid washing or a second cold rolling with annealing during operation, decarbonization annealing and recrystallization annealing, etc., and is characterized in that the hot rolled plate before being treated with acid washing is done with welding end to end and then continuous endless rolling is done by a mill with multi-stands; a warm rolling is realized by that mechanical energy is transformed into heat energy during the rolling and the temperature of the steel plate raises; the tension among each mill stand is 100-300 N / mm <2> and 30-80 N / mm<2> for the last mill stand; the draft is 15-30 percent and 5-15 percent for the last mill stand and the outlet speed of the rolling mill is no less than 500m / min and the thickness of the finished product is 0.2-0.8mm. By adopting a plurality of mill stands to realize the warm rolling, the invention effectively solves the breakage occurred in edges; the last mill stand is served as the pass mill stand of finished products so as to guarantee the quality of the surface of the steel strip; large tension is adopted during the rolling so as to ensure that a forward slipping area can be reduced and deformation bands are increased. Compared with the method by a single mill stand, the method of the invention prolongs the cycle of roll changing, reduces the labor intensity, shortens the production cycle and improves productivity and quality of steel plates. In addition, the method of welding from head to tail for transition with low-silicon steel can effectively solve the problem of breakage during the welding of the high-silicon electrical steel.

Description

technical field [0001] The invention belongs to steel rolling technology, in particular to a cold rolling method for high-silicon electrical steel Background technique [0002] In the past, cold-rolled electrical steel was produced by a single-stand cold rolling method or a secondary cold-rolling method with intermediate annealing. In order to ensure the surface quality of the finished product, the finished pass of the cold-rolled product must be completed with a new roll, so the roll change Operation is frequent. In addition, due to the reciprocating rolling of a single stand, not only the amount of head and tail cutting is increased, but the yield is low, and the rolling speed needs to be increased and decreased frequently. The low rolling speed is also a major factor restricting the increase in output. In particular, high-silicon electrical steel with a Si content greater than 2% is usually cold-rolled by a 20-roll mill and rolled at a low speed due to its high deformati...

AI Technical Summary

Problems solved by technology

However, if high-silicon electrical steel is produced by continuous rolling, as the silicon content increases, the edge cracks will become more serious, and the welding strip will be broken more frequently.

Images