Black chemical conversion coating film forming method and a blackened anti-corrosion film forming method of a metal member having a zinc or zinc alloy surfaces.

摘要

This invention administering to the metal component surface which possesses the spelter or spelter alloy surface, satisfactory degree of black and offers the chemical conversion coating service water solution which can be applied to the finishing manner and the said treatment manner of chrome free rust prevention performance can be granted. The said aqueous solution is not included, the chrome ion of the trivalent or 6 value the phosphoric acid ion 5 - 20g, the divalent iron ion 0.1 - 3g, the divalent manganese ion 1 - 10g, 1 - 3g includes the nitric acid ion in the said aqueous solution of 1 liters, pH is 1 - 3. Soaking the said metal component in the said aqueous solution, it forms₃₄ the black membrane of FeO, next forms the chemical conversion coating of cerium oxide, next, the silica quality membrane forms.