| 摘要 |
<P>PROBLEM TO BE SOLVED: To obtain a grain oriented silicon steel sheet which has stably excellent magnetic properties by effectively allowing secondary recrystallization to occur without using inhibitors. <P>SOLUTION: The grain oriented silicon steel sheet is produced by using a steel slab produced by using a molten steel having a composition containing, by mass, ≤0.08% C, 2.0 to 6.5% Si, and 0.005 to 3.0% Mn, and in which the content of Al is reduced to <100 ppm, and the contents of N, S, and Se are reduced to ≤50 ppm, respectively. In this case, a slab heating temperature prior to hot rough rolling is controlled to ≤1,280°C. Further, rough rolling at a cumulative draft of ≥70% containing a pass at ≥1,050°C and at a draft of ≥30% for at least one time is performed. After that, the steel sheet is subjected to finish rolling, and, successively, a cooling rate after the finish rolling is controlled to ≥20°C/s on the average, and the steel sheet is coiled round a coil, so that oxide essentially consisting of magnetite is formed on the surface of the hot rolled sheet. <P>COPYRIGHT: (C)2003,JPO |
