| 摘要 |
To provide a piston ring product in which hard particles are uniformly filled in cracks in hard chromium plating formed on the sliding surface and which has excellent long term use stability. To this end, a composite chromium plating film is provided, comprising a hard chromium plating film having crack-like grooves filled with hard particles, wherein the hard particles used are irregular particles having powder characteristics of an average circularity of 0.70 to 0.85, an average equivalent circle diameter of 6.0 µm or less and an aspect ratio of 1.3 or more. The composite chromium plating film is applied to the sliding surface of a piston ring product. |
