| 摘要 |
PURPOSE:To maintain the small iron loss independently of strain relief annealing by diffusing a forsterite reaction inhibitor stuck partially to the surface of a steel sheet in the base iron and forming a region in which a forsterite film has different thicknesses so as to subdivide the width of a magnetic domain. CONSTITUTION:A hot rolled silicon steel sheet is cold rolled once or cold rolled twice or more while carrying out process annealing between cold rolling stages. A forsterite reaction inhibitor is linearly stuck to the surfasce of the cold rolled silicon steel sheet having the final thickness, and energy is applied only to the stuck region to diffuse partially the inhibitor in the base iron. The steel sheet is then coated with forsterite as a protective coating material for annealing and is subjected to final finish annealing. By this method, deterioration in the characteristics of the steel sheet is prevented even after strain relief annealing at a high temp., and the small iron loss is maintained. |
