| 摘要 |
PURPOSE:To manufacture an electrical steel sheet having a more significant iron loss reducing effect and causing no deterioration in the iron loss characteristics even by annealing at high temp. by making linear grooves by which groups of fine recrystallized grains are not formed during strain relief annealing in a grain-oriented electrical steel sheet subjected to finish annealing. CONSTITUTION:A grain-oriented electrical steel sheet subjected to finish annealing, contg. 2.0-4.5wt% Si and having a forsterite film on the surface is prepd. The forsterite film on the surface of the steel sheet is linearly removed within the angle range of + or -45 deg. having a base line in a direction perpendicular to the rolling direction under conditions under which <=30% strain is produced in the base iron. The steel sheet is electrolytically or chemically etched through the film to make linear grooves in the base iron. Thus, the desired electrical steel sheet having linear grooves which reach the base iron within the angle range of + or -45 deg. is obtd. High strain parts in which groups of fine recrystallized grains are formed during strain relief annealing are not present around the linear grooves. |
