Patent ID: 9506138
Filing Date: 2016-11-29
CPC Classification: B23P,C23C,F16J

Claim Text:
1. A method of manufacturing a piston ring, the method comprising: forming a piston ring base by processing a low-alloy steel or carbon steel, each of the low-alloy steel and the carbon steel having a Vickers hardness of 350 Hv to 550 Hv; cleaning a surface of the piston ring base by irradiating the surface with a metal ion, which is an ionized metal target, while maintaining a temperature of the piston ring base at a temperature that does not cause the hardness of the piston ring base to decrease; and forming a hard film on an outer peripheral sliding surface of the piston ring base by an ion plating method, the hard film being composed of an ion plating coat having a film thickness of from 5 μm to 30 μm, a porosity of from 0.5% to 1.5%, and a Vickers hardness of from 800 Hv to 2300 Hv.