| 摘要 |
There is disclosed a piston ring having an annular piston ring base material and a plating film formed on the outer peripheral surface of the piston ring base material. The plating film is a chromium plating formed using a trivalent chromium plating solution which is an aqueous solution containing a trivalent chromium compound, a pH buffering agent, a sulfamate compound, an aminocarbonyl compound and a complexing agent that includes at least one selected from among dicarboxylic acids and their salts. |
