| 摘要 |
PROBLEM TO BE SOLVED: To produce a grain oriented silicon steel sheet minimal in iron loss by subjecting a continuously cast slab of specific composition consisting of C, Si, Mn, S, Se, and Fe to specific heating and soaking, to hot rolling, and then to specific cold rolling. SOLUTION: A continuously cast slab, which has a composition consisting of, by weight, 0.015-0.100% C, 2.0-4.0% Si, 0.03-0.12% Mn, 0.005-0.050% of either or both of S and Se, and the balance essentially Fe and further containing, if necessary, 0.003-0.3% of one or more elements among Cu, Sb, Sn, Mo, Ge, B, Te, As, and Bi, is heated to 1320-1450 deg.C and soaked. At this time, if necessary, heating deformation is applied, before heating up to >=1250 deg.C, to the slab at <=50% draft, and temp. is raised from 1250 deg.C upward at a rate of >=5 deg.C/min. Then, the slab is hot-rolled, and, after hot rolled plate annealing, if necessary, the resultant hot rolled plate is cold-rolled twice while process-annealed between cold rolling stages. At this time, at the time of the second cold rolling by means of plural passes, the cold rolled sheet is held at 130-350 deg.C for >=1min between one or more passes. This cold rolled sheet is subjected to decarburizing and primary recrystallization annealing and to final finish annealing. |
