TRIVALENT CHROMATE LIQUID, AND METHOD OF FORMING HEXAVALENT CHROMIUM-FREE CORROSION RESISTANT FILM ON ZINC-NICKEL ALLOY PLATING USING THE LIQUID

摘要

PROBLEM TO BE SOLVED: To provide a method of forming a trivalent chromate film having high corrosion resistance on zinc-nickel alloy plating using a trivalent chromate liquid which is less liable to affect human body and environment.;SOLUTION: The trivalent chromate liquid contains ≥0.01 mol/L of nitrate ions and a zinc compound, and has a pH in the range of 1.5 to 5.5. The method of forming a hexavalent chromium-free corrosion resistant film includes a step wherein a zinc-nickel alloy plating film on a substrate is dipped into the trivalent chromate liquid at 10 to 80°C.;COPYRIGHT: (C)2005,JPO&NCIPI