| 摘要 |
PROBLEM TO BE SOLVED: To provide a manufacturing method for a nonoriented silicon steel sheet with excellent magnetic flux density and core loss superior to those of the conventional one. SOLUTION: A steel slab having a composition containing, by mass, 1.5-4.0% Si and 0.005-1.50% Mn is hot rolled, subjected to hot rolled plate annealing, and cold rolled once or cold rolled two or more times while process annealed between cold rolling stages so as to be finished to final sheet thickness, and the resultant steel sheet is subjected to recrystallization annealing, followed by insulation coating if necessary. In this method for manufacturing the nonoriented silicon steel sheet, the amounts of Al and N contained in the steel slab are regulated to <=0.017 mass% and <=0.0030 mass%, respectively, and average grain size after hot rolled plate annealing is controlled to 0.050-0.40 mm. |
