Structure and formation process of the glass film on grain-oriented silicon steel using aluminum nitride as an inhibitor

The oxide film formed during secondary recrystallization annealing of grain-oriented 3% Si steel using aluminum nitride as an inhibitor was investigated by x-ray diffraction analysis (XRD), glow discharge optical emission spectrometry (GD-OES), and quantitative chemical analysis (CA) in order to clarify the structure and the formation process. Spinel (MgAl2O4) was identified in addition to forsterite (Mg2SiO4) by XRD. From the consideration on the basis of the element distribution of Mg, Si, Al in the glass film and the quantitative correlation between the amount of spinel and that of forsterite, it was concluded that spinel was formed by the substitution reaction of Si in forsterite film for Al generated by decomposition of AIN.