Grain oriented silicon steel sheet having excellent primary film properties

摘要

A grain oriented silicon steel sheet having excellent primary glass film property and magnetic property, comprising 2.0 to 5.0% by weight of Si, wherein a primary glass film formed during secondary recrystallization annealing is composed mainly of forsterite (Mg2SiO4) and an oxide containing Al, mainly of spinel (MgAl2O4), or Al and Si, mainly of cordierite (MgO2Al4Si5O18) and/or sapphirine (Mg4Al10Si2O23), and in an analysis of the surface of the steel sheet by glow discharge optical emission spectrometry analysis (GDS analysis), a peak derived from Al is separated from a peak derived from Mg, and, preferably, the peak derived from Al is separated from the peak derived from Mg and the distance (time) from the surface of the steel sheet at which the peak derived from Al is 1.2 times or more the distance from the surface of the steel sheet at which the peak derived from Mg appears.