PRODUCTION OF HIGH CORROSION RESISTANT ELECTROGALVANIZED STEEL SHEET EXCELLENT IN CHEMICAL CONVERTIBILITY

摘要

PURPOSE: To provide a producing method for improving the chemical convertibility of a high Cr-contg. electrogalvanized steel sheet without affecting any influence on its excellent corrosion resistance in the method for producing a high Cr-contg. electrogalvanized steel sheet. ;CONSTITUTION: An electrogalvanized steel sheet contg., by weight, 5-30% Cr and 0.1-10% iron group metal is brought into contact with a mixed aq. soln. of nitric acid and nitrous acid, by which a dense and uniform chemically converted film can be obtd. The influence on its corrosion resistance is eliminated, and its performance after coating, particularly, its coating film adhesion can be improved. As the iron group metal, Ni is most preferably used.;COPYRIGHT: (C)1995,JPO