| 摘要 |
<P>PROBLEM TO BE SOLVED: To more stably produce a grain oriented silicon steel sheet which has excellent magnetic properties by properly controlling primarily recrystallized grains and coating an oxide film having excellent adhesion on the surface. <P>SOLUTION: A steel slab having a componential composition containing, by mass, ≤0.08% C, 2.0 to 8.0% 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 is hot-rolled, and is, if required, subjected to hot rolled sheet annealing. After that, the steel sheet is subjected to cold rolling for one time or for ≥two times including process annealing, and then subjected to annealing for decarburization and then subjected to final finish annealing after a separation agent for annealing essentially consisting of MgO is applied to produce a grain oriented silicon steel sheet. In this case, one or more kinds selected from the hydroxides of Be, Mg, Ca, Sr, Ba, Zn, Sb, Fe, Ni, and Mn having a BET (Brunauer, Emett and Teller) specific surface area of 0.8 to 4.5 m<SP>2</SP>/g, and titanium oxide powder having a BET specific surface area of 5.0 to 14.9 m<SP>2</SP>/g are added to the separation agent for annealing. <P>COPYRIGHT: (C)2003,JPO |
