| 摘要 |
PURPOSE: To obtain a steel sheet having high magnetic flux density, low iron loss and low magnetostriction and scarcely developing forsterite primary film by regulating V, N, Al contents, primary annealing temp., FeO/SiO2 on the surface oxide layer and annealing releasing agent of a silicon steel sheet. CONSTITUTION: Soaking is executed to a steel slab containing, by wt.%, 1-4 Sr, 0.01-0.05 Al, 0.01-0.10 V, <=0.01 S at 1000-1270 deg.C, and hot-rolling is executed at >=850 deg.C finish temp. and cold-rolling, primary and secondary recrystallized annealings are executed. At this time, in either process of a process in the molten steel or a process before reaching 950 deg.C secondary recrystallized annealing temp. in the secondary recrystallized annealing process after hot-rolling, the total 0.01-0.04% N is added to the steel and the N quantity is defined as the equations I and III and the inequalities II and IV are satisfied. Further, the primary recrystallized annealing is executed at T0 temp. in the inequality V and thereafter, <=1500ppm oxygen coating quantity and <=0.40 FeO/SiO2 in the oxide film layer are made to be contained, and the annealing releasing agent containing 0.5-20wt parts of sulfide of Li and K, etc., in MgO and/or 2-20wt parts of carbonate, etc., thereof to 100wt parts of MgO is coated before the secondary crystallize annealing. |
