Piston ring

摘要

A piston ring (R) includes: a refined steel including: carbon C in a range of 0.20 % mass to 0.90 % mass, silicon Si in a range of 0.10 % mass to less than 0.60 % mass, manganese Mn in a range of 0.20 % mass to 1.50 % mass, chromium Cr in a range of 0.30 % mass to 2.00 % mass, and a remnant including: iron Fe, and an unavoidable impurity. A parameter A calculated from the following expression (1) based on contents of the Si, Mn and Cr is 9.0 or less: parameter A = 8.8 Si + 1.6 Mn + 1.7 Cr --- expression (1). A parameter B calculated from the following expression (2) based on contents of the C, Si, Mn and Cr is 10.8 or more: parameter B = 36 C + 4.2 Si + 3.8 Mn + 4.5 Cr --- expression (2).