| 摘要 |
PURPOSE:To obtain a grain-oriented silicon steel sheet holding low iron loss value and good in a space factor after being subjected to stress relief annealing. CONSTITUTION:The low iron loss grain-oriented silicon steel sheet in which the surface layer part of ferrite in a grain-oriented silicon steel sheet coated with a tension-applied insulating film as final product is provided with molten and solidified line parts in which the width is regulated to 50 to 300mum, the depth is regulated to 5 to 35% to the sheet thickness of the steel sheet, the angle is regulated to <=+ or -15 deg. from the right angles to the sheet passing direction and the distance is regulated to 5 to 30mm and excellent in the space factor is produced. Furthermore, the surface of the grain-oriented silicon steel sheet after being subjected to finish annealing or coated with an insulating film and dried after being subjected to finish annealing is irradiated with laser beams to form molten and solidified line parts in which the width is regulated to 50 to 300mum, the depth is regulated to 5 to 35% to the sheet thickness of the steel sheet, the angle is regulated to <=+ or -15 deg. from the right angles to the sheet passing direction and the distance is regulated to 5 to 30mm, and after that, tension-applied insulating film treatment is executed. |
