| 摘要 |
PURPOSE:To produce a nonoriented silicon steel sheet having high magnetic flux density and excellent in external surface appearance by subjecting a hot rolled strip of low carbon steel to light-degree cold rolling and to short-time annealing, on the premise that continuous annealing is done, and controlling crystalline grain size. CONSTITUTION:A slab which has a composition consisting of, by weight, <=0.02% C, <=4.0% Si or (Si+Al), <=1.0% Mn, <=0.2% P, and the balance essentially Fe and further containing, if necessary, <=0.10%, in total, of Sb and/or Sn is hot-rolled into a hot rolled steel strip, cold-rolled at 5-15% draft, and annealed so that crystalline grain size is regulated to 100-200mum. Subsequently, one is formed to the final sheet thickness by means of cold rolling and then subjected to final annealing, and the other is cold-rolled at >=50% draft, annealed so that <=20mum crystalline grain size is reached, further cold-rolled at 1-15% draft to the product sheet thickness, and then subjected to final annealing. |
