| 摘要 |
PURPOSE: To stably obtain a grain oriented silicon steel sheet excellent in magnetic properties and film characteristic by means of low temp. slab heating while reducing nitriding treatment by controlling the thermal hysteresis from solidification to hot rolling of a slab with a specific composition. CONSTITUTION: A slab, having a composition consisting of, by weight, 0.025-0.100% C, 2.2-5.0% Si, 0.015-0.080% acid-soluble Al, <=0.0130% N, S and Se by the amounts satisfying S+0.405Se-<=0.0400%, <=0.30% Mn, and the balance Fe, is heated at <1280 deg.C, hot-rolled, and subjected, if necessary, to hot rolled plate annealing. Subsequently, the resulting hot rolled steel plate is subjected to one or more cold rolling stages including final cold rolling at >=80% draft and also including, if necessary, process annealing performed between the cold rolling stages. Then, decarburizing annealing and finish annealing are done, by which the silicon steel sheet can be obtained. In this method, in the course between the completion of solidification of the slab and the heating of the slab before hot rolling, the slab is heated at 1300-1450 deg.C for >=5min. Further, in the course between the completion of hot rolling and the starting of secondary recrystallization at final finish annealing, the absorption of the prescribed amount of nitrogen is performed. |
