LOW-IRON LOSS GRAIN ORIENTED ELECTROMAGNETIC STEEL SHEET AND METHOD OF PRODUCING THE SAME

摘要

A low-iron loss grain oriented electromagnetic steel sheet subjected to final finishing annealing has a plurality of linear grooves formed on the ferrite surface of the steel sheet in a direction across the rolling direction, so as to improve the magnetic: characteristics of the steel sheet. The linear grooves have a substantially rectangular cross-sectional shape in which the angle of a groove side wall to the direction of the thickness of the sheet is about 60.degree. or less. Projections are present at a bottom portion of the groove, and the depth at the top of the projection at the groove bottom is at least about 1/2 of the maximum groove depth. The steel sheet maintains a low iron loss even after stress relief annealing. The present invention provides a method of stably producing the steel sheet.