| 摘要 |
PROBLEM TO BE SOLVED: To obtain a grain-oriented silicon steel sheet excellent in magnetic properties and surface characteristic by adding nitrogen at secondary recrystallization annealing and also adding an antimony compound to the magnesia to be applied, at the time of producing a grain-oriented silicon steel sheet of specific composition. SOLUTION: A steel, having a composition containing, by weight, 1-4% Si, 0.01-0.5% Al, 0.01-0.10% V, 0.0015-0.0200% Hf, and <=0.01% S, is refined and subjected, in succession, to slab soaking at 1000-1270 deg.C, to hot rolling at >=850 deg.C hot rolling finishing temp., to cold rolling, to primary recrystallization annealing, and then to secondary recrystallization annealing, by which the grain-oriented silicon steel sheet is produced. At this time, nitrogen is added to the molten steel so that total N content becomes 0.01-0.04% and also N content and V content satisfy a constant relation, and an antimony compound is added by 0.05-5.0% to the magnesia to be applied for the formation of a primary film before secondary recrystallization annealing, and further, the average temp. rise rate between 300 and 1150 deg.C at secondary annealing is regulated to >50 deg.C/hr. |
