METHOD FOR TREATING AN ELECTROMAGNETIC STEEL SHEET BY LASER-BEAM IRRADIATION

摘要

In a method for producing electromagnetic steels. the steels finally annealed are treated by the steps of: irradiating by using a laser beam the surface of the electromagnetic steel sheet which has been finally annealed, thereby locally forming marks of the laser-beam irradiation on the surface of the steel sheet, and subsequently, subjecting the steel sheet to the formation of an insulating film on the sheet surface at a temperature of the sheet not exceeding 600 DEG C. By this treatment, watt loss, magnetostriction, space factor, workability, ability to withstand high voltage and insulating property are improved over those of conventional electromagnetic steels.