| 摘要 |
PURPOSE: To produce a semiprocessed nonoriented silicon steel sheet minimal in anisotropy of magnetic properties by applying specific cold rolling to a steel sheet having a specific composition consisting of C, Si, Mn, P, S, Al, N, 0, and Fe. CONSTITUTION: A slab, having a composition consisting of, by weight, <=0.015% C, 0.05-1.0% Si, 0.1-1.5% Mn, <=0.15% P, <=0.03% S, <=1.0% sol.Al, <=0,.01% T.N, <=0.02% T.O, and the balance iron with inevitable impurities, is hot-rolled. The resulting hot rolled plate is subjected to hot rolled plate annealing at 700-1000 deg.C, if necessary. Then, this hot rolled plate is cold-rolled twice, while process-annealed between the cold rolling stages, to the final product thickness. At this time, the second cold rolling is done at 2-15% draft. Further, respective diameters of the upper and the lower work roll are made different from each other, and also (diameter of small-diameter roll)/(diameter of large-diameter roll)<=0.8 is satisfied. |
