Patent ID: 9617615
Date: 2017-04-11
CPC Classifications: C21D,C22C,H01F

Claim:
1. A grain-oriented electrical steel sheet before or after subjection to non-heat resistant magnetic domain refining treatment, the grain-oriented electrical steel sheet comprising: a steel sheet substrate formed by rolling; a forsterite base film formed on a surface of the steel sheet substrate; and an insulating tension coating formed on the forsterite base film, wherein contents by mass % of Ti, Al, and Fe in the forsterite base film, obtained through quantitative analysis by applying correction with a ZAF method to results of fluorescent X-ray analysis on the surface of the forsterite base film after removing the insulating tension coating are each specified as FX(Ti), FX(Al), and FX(Fe), the following formulas (1) and (2) are satisfied, a frequency of crystal boundaries of secondary recrystallized grains in the steel sheet substrate in a width direction and orthogonal to a rolling direction of the steel sheet substrate is 20 grain boundaries/100 mm or less, a mean thickness of the forsterite base film is specified as t(Fo), and a thickness of the insulating tension coating is specified as t(C), the following formula (3) is satisfied: a coating amount M2of the insulating tension coating per steel sheet surface is 4.5 g/m in the ZAF method, “Z” refers to a correction of fluorescent X-ray yield by an atomic number, “A” refers to a correction of X-ray absorption of an observed wavelength by a coexistent element, and “F” refers to secondary excitation correction by a fluorescent X-ray of a coexistent element.