摘要 |
PURPOSE:To improve electrical adhesiveness without deteriorating magnetic characteristics by forming an insulating film of a chromate or phosphate system on the surface of a grain oriented Fe-Cr electrical steel sheet which is adjusted in surface roughness. CONSTITUTION:The surface of the grain oriented Fe-Cr cold rolled electrical steel sheet is subjected to immersion in aqua regia, etc., by which the surface roughness is adjusted to <=1.0mum center line average height Ra. A coating liquid of the chromate or phosphate system is coated and baked on the surface thereof to form the insulating film. The compsn. of the steel sheet preferably consists essentially of 8-20wt% Cr and contains <=4% Al and Si and <=3% >=1 kinds among P, Sn, Ti, V, Mo, W, Zr, Nb, Hf and Ta. This rustproof electrical steel sheet with the insulating film has the excellent corrosion resistance, magnetic characteristics and film adhesiveness. |