| 摘要 |
PROBLEM TO BE SOLVED: To stably obtain a steel sheet free from edge crack and good in magnetic properties by controlling the contents of acid soluble Al, N, Se and S in steel contg. specified ratio of C, Si and Mn, the size of the grains in the slab columnar crystal parts after casting and the heating temp. SOLUTION: Steel contg., by weight, 0.005 to 0.08% C, 1.0 to 7.0% Si and 0.03 to 2.5% Mn is melted to cast to form into a silicon steel slab, which is successively subjected to heating, hot rolling and hot rolled sheet annealing and is thereafter subjected to cold rolling to control its sheet thickness into the final one, and, finish annealing is executed to produce a grain oriented silicon steel sheet. At this time, the contents of acid soluble Al, N, Se and S in the steel are controlled to the ranges of, by weight, 0.001 to 0.030% acid soluble Al, 0.003 to 0.010% N and <=0.035% Se+2.47S, the size of the grains in the columnar crystal parts in the slab after the casting is controlled to <=10 mm on the average by the size equivalent to a circle in the cross section vertical to the elongating direction of the columnar crystals, and the slab heating temp. is controlled to <=1300 deg.C. |
