| abstract |
An nickel plating layer ( 5 a ) intended for corrosion current distribution is formed over a body ( 2 ), and a 0.05 to 2.5 micrometers thick surface chrome plating layer ( 6 ) made of trivalent chromium is formed on the surface thereof using basic chromium sulfate as a source of metal. Further on the same, a not less than 7 nm thick chromium compound film ( 7 ) is formed by cathode acidic electrolytic chromatin. The corrosion distribution nickel plating layer ( 5 a ) has a function of forming a microporous structure, a microcrack structure, or the both of the same in the surface chrome plating layer ( 6 ). |