| 摘要 |
PURPOSE:To stably produce a grain-oriented silicon steel sheet excellent in magnetic properties by subjecting a slab having a specific composition consisting of C, Si, Al, N, S, Se, Mn, and Fe to specific hot rolling and then to specific cold rolling. CONSTITUTION:A slab having a composition consisting of, by weight, <=0.020% C, 2.5-4.5% Si, 0.010-0.060% acid soluble Al, 0.0030-0.0130% N, <=0.014% (S+0.405Se), 0.05-0.8% Mn, and the balance Fe with inevitable impurities is heated to <1280 deg.C and hot-rolled. In this hot rolling, finishing temp. is regulated to >900-<1150 deg.C and the cumulative reduction of area in the final three passes in finish rolling is regulated to >=50%. Further, it is preferable to regulate the reduction of area in the final pass to >=20%. The resulting hot rolled plate is cold-rolled once at >80% reduction of area or is subjected to two or more cold rollings including final cold rolling at >80% reduction of area while process-annealed between the cold rolling stages, by which the final sheet thickness is reached. Then the resulting cold rolled sheet is subjected to decarburizing annealing and finish annealing, by which the grain-oriented silicon steel sheet excellent in magnetic properties can be obtained. |
