Method for treating an electromagnetic steel sheet and an electromagnetic steel sheet having marks of laser-beam irradiation on its surface

摘要

A process of providing electromagnetic steel strips or sheet with excellent magnetic properties. The process comprises the steps of: irradiating with a laser-beam the surface of an electromagnetic steel sheet which has been finally annealed, thereby locally forming marks of the laser-beam irradiation on the surface of the steel, 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.