GRAIN-ORIENTED ELECTRICAL STEEL SHEET AND METHOD OF MANUFACTURING SAME

摘要

A grain-oriented electrical steel sheet has low iron loss properties obtained though magnetic domain refining treatment by a chemical means. The steel sheet has a linear groove extending in a direction forming an angle of 45° or less with a direction orthogonal to a rolling direction of the steel sheet, in which presence frequency of fine grains with a length in the rolling direction of 1 mm or less in a floor portion of the groove is 10% or less, including 0% indicative of the absence of fine grains, the groove is provided with a forsterite film in an amount of 0.6 g/m2 or more in terms of Mg coating amount per one surface of the steel sheet, and an average of angles (3 angles) formed by <100> axes of secondary recrystallized grains facing the rolling direction and a rolling plane of the steel sheet is 3° or less.