ELECTROLYTIC SOLUTION FOR ZN-NI ALLOY PLATING AND PLATING METHOD FOR ZN-NI ALLOY

摘要

PURPOSE:To obtain uniform plating with high corrosion resistance by carrying out plating at a specified pH using an electrolytic soln. contg. specified amounts of Ni ion, Zn ion, acetate ion and citrate ion. CONSTITUTION:This invention relates to an electrolytic soln. for Zn-Ni alloy plating used in the manufacture of a surface-treated steel plate with high corrosion resistance for a car. By plating a steel plate with a Zn-Ni alloy at 1.5- 5.0pH using the electrolytic soln. contg. 10-90g/l Ni ion, 10-65g/l Zn ion and =0.1mol/l in total of acetate ion and/or citrate ion and having 0.5-1.5mol ratio of Ni/Zn, Zn-Ni alloy (single gamma phase) plating with 8-20% Ni content is obtd.