GRAIN ORIENTED SILICON STEEL SHEET WITH LOW IRON LOSS, EXCELLENT IN WATER RESISTANCE OF FILM AND RUSTING RESISTANCE DURING STORAGE

摘要

PURPOSE: To provide a grain oriented silicon steel sheet in which iron loss is reduced by forming an aluminum borate film capable of applying greater tension than heretofore on the surface and also the water resistance of the surface film and rusting during storage are improved. ;CONSTITUTION: This steel sheet is a grain oriented silicon steel sheet with low iron loss, in which the amount of boron oxide and/or boric acid, existing in an aluminum borate insulating film at the outermost surface, is regulated to ≤5% by weight ratio based on the whole film. Further, the steel sheet is a grain oriented silicon steel sheet with low iron loss, in which crystalline aluminum borate and amorphous phases having boron and silicon as constituents are contained in the aluminum borate insulating film at the outermost surface and also the amount of boron oxide and/or boric acid is regulated to ≤5% by weight ratio based on the whole film.;COPYRIGHT: (C)1996,JPO