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 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 DEG 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.