| 摘要 |
PROBLEM TO BE SOLVED: To produce a silicon steel sheet high in magnetic flux density and low in core loss at a low cost, at the time of subjecting a slab contg. specified amounts of Si, Al, Mn, C, N, S and Fe to finish hot rolling, by executing the final pass at specified strain rate and tension and executing no water injection for a specified time after the completion of the hot rolling. SOLUTION: A slab contg., by weight, 2<=(Si+SAl)<=4.5-0.1 to 1% Mn, <=0.005% C, <=0.005% N, <=0.005% S, and the balance substantial Fe is subjected to hot rolling, pickling, cold rolling and finish annealing to produce a nonoriented silicon steel sheet. At the time of the finish hot rolling, the strain rate in the final pass is regulated to >=150s<-1> , and the tension between the final two stands is regulated to >=1.5kg/mm<2> . After the completion of the hot rolling, it is coiled for a time (t) prescribed by the inequality without executing water injection. T in the inequality denotes the hot rolling finishing temp. ( deg.C), and 950<=T<=1150 is satisfied. After the primary cold rolling stage, it is subjected to the finish annealing and is furthermore subjected to 2 to 20% skinpass rolling. The sheet bars after the rough rolling are joined, and continuous rolling is executed. |
