Patent ID: 9347559
Filing Date: 2016-05-24
CPC Classification: C23C,F16J

Claim Text:
1. A piston ring comprising: a substrate; a TiN coating having a thickness of 10-60 μm on a peripheral sliding surface of the substrate, the texture coefficients of a (111) plane and a (220) plane of TiN in the X-ray diffraction of a surface of said TiN coating being respectively 1.2-1.65 and 1.0-1.2, with the texture coefficient of a (111) plane of TiN>the texture coefficient of a (220) plane of TiN>the texture coefficient of a (200) plane of TiN; wherein said TiN coating is formed in a nitrogen atmosphere consisting of N wherein said substrate has a composition consisting of, by mass, 0.45-0.55% of C, 0.15-0.35% of Si, 0.65-0.95% of Mn, 0.80-1.10% of Cr, and 0.15-0.25% of V, the balance being Fe and inevitable impurities, and comprises spheroidal cementite having an average particle size of 0.1-1.5 μm dispersed in an annealed martensite matrix.