GRAIN-ORIENTED ELECTRICAL STEEL SHEET AND METHOD FOR IMPROVING IRON LOSS PROPERTIES THEREOF

摘要

Provided is a grain-oriented electrical steel sheet, on which magnetic domain refining treatment by strain application has been performed, having an insulating coating with excellent insulation properties and corrosion resistance. The grain-oriented electrical steel sheet is obtained by irradiating a steel sheet with a high-energy beam so as to apply, to the steel sheet, linear strain extending in a direction that intersects a rolling direction of the steel sheet, and then re-forming an insulating coating on the steel sheet, in which in an irradiation mark region due to the high-energy beam, a ratio of an area containing defects on the insulating coating is 40 % or less, a maximum width of the irradiation mark region in the rolling direction is 250 µm or less, and a thickness of the insulating coating is 0.3 µm or more and 2.0 µm or less.