| 摘要 |
PURPOSE:To stably manufacture a grain-oriented magnetic steel sheet reduced in iron loss by locally applying an etching resist agent to the surface of a finish- annealed grain-oriented magnetic steel sheet so that linear unapplied parts are allowed to remain, subjecting the above sheet surface to electrolytic etching, and then applying top coat to the whole surface of the above sheet. CONSTITUTION:A nonconductive etching resist agent is applied to the surface of a finish-annealed grain-oriented magnetic steel sheet so that linear unapplied parts are allowed to remain at a right angle or <=about 30 deg. angle with respect to the rolling direction of the steel. At this time, the pitch of the linear region in the rolling direction of the steel sheet, the width of each linear region, and the thickness of the resist agent are regulated to about 1-30mm, about 5-500mu, and >=about 2mu, respectively. Subsequently, electrolytic etching is carried out to form grooves of about 5-30mu depth in the steel sheet and the etching resist agent is removed, and then, top coat treatment is applied to the above steel sheet. By this method, the grain-oriented magnetic sheet with low iron loss free from deterioration in iron loss due to stress relieving annealing and excellent in space factor can be stably obtained. |
