Are superior in insulating Characteristic, driving out Characteristic, heat resistance and corrosion resistance the electromagnetic steel sheet and its production manner

摘要

PURPOSE:To obtain a magnetic steel sheet excellent in insulating property, suitability to blanking, resistance to heat and corrosion and maintaining the insulating property and corrosion resistance even after heat treatment such as strain relief annealing. CONSTITUTION:A chromate film contg. 5-300mg/m2 (expressed in terms of Cr) chromium oxide hydrate, chromium oxide and metallic Cr is formed as a lower layer on the surface of a magnetic steel sheet and an inorg.-org. insulating film consists of at least one of a Cr compd. and a phosphoric acid compd. and an org. resin principal as components is formed as an upper layer on the chromate film.