| 摘要 |
PROBLEM TO BE SOLVED: To provide a Ca-added nonoriented silicon steel sheet excellent in punchability. SOLUTION: This steel sheet is the one contg., by weight, <=0.01% C, <=4.0% Si, 0.1 to 2.5% Mn, <=2.5% Al and 0.0001 to 0.01% Ca, in which among CaS simple substances or precipitates contg. CaS, the distribution density of the precipitates of >=5 μm diameter is <=20 pieces/mm2, the surface of the steel sheet is provided with an insulating film of >=0.2 g/m2 coating weight, and the weight fractional ratio of a resin in the insulating film satisfies the inequality of x (wt.%)>=120×[Ca (wt.%)]1/2. |
