| 摘要 |
PROBLEM TO BE SOLVED: To make better the formation of a glass film even in the case the temp. rising rate in annealing is increased by specifying the compsn. of a steel sheet and the amt. of an annealed film to be formed and controlling the profiles of Al and Fe, the ratio in which the peeling of a film is not generated at the time of bending and core loss characteristics therein. SOLUTION: The compsn. of this grain oriented silicon steel sheet is composed of, by weight, <=0.005% C, 2.0 to 7.0% Si, and the balance Fe with inevitable impurities, and, on the surface, an annealed film composed of the oxides of Mg, Si and Al is formed. The amt. of the annealed film to be formed is controlled to 1 to 5 g/m2 per side of the steel sheet, and the profiles of Al and Fe in glow discharge emission analysis are allowed to satisfy the inequality I. Moreover, the ratio (y)(%) in which the peeling of the film is not generated in the case of 20 mm diameter bending is allowed to satisfy the inequality II (d) denotes the sheet thickness mm), and core loss characteristics are allowed to satisfy the inequality III. The grain oriented silicon steel sheet is preferably subjected to magnetic domain fractionating treatment as well. Preferably, the compsn. is moreover incorporated with <=400 ppm Al and a well-known inhibitor. |
