SURFACE TREATMENT OF AMORPHOUS MAGNETIC STEEL STRIP

• Main Authors: UMEZONO AKIMI, KAWASAKI HIRONOBU, HAYASHI TOMOHIKO
• Format: Patent
• Language: English
• Published: 01.04.1985
• Edition: 4
• Subjects: CHEMICAL SURFACE TREATMENT; CHEMISTRY; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATIONOR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY IONIMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING MATERIAL WITH METALLIC MATERIAL; COATING METALLIC MATERIAL; DIFFUSION TREATMENT OF METALLIC MATERIAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION INGENERAL; METALLURGY; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THESURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION

PURPOSE:To form an insulating film having superior corrosion resistance on the surface of an amorphous magnetic steel strip by coating a treating soln. contg. properly blended phosphoric acid, chromic anhydride and a number of metallic ions on the surface of the steel strip and by drying the soln. CONSTITUTION:A treating soln. contg. 20-300g/l phosphoric acid, chromic anhydride by 5-60wt% of the amount of the phosphoric acid and a number of metallic ions such as Zn ions from Zn(OH)2 is prepd. The treating soln. is coated on the surface of an amorphous magnetic steel strip, and it is dried and baked in a hot stove or the like. By this method an insulating film having superior corrosion resistance and preventing well the deterioration of magnetism by corrosion or other cause with the lapse of time can be formed on the surface of the amorphous magnetic steel strip.