Patent ID: 9404578
Filing Date: 2016-08-02
CPC Classification: C23C,C25D,F16J

Claim Text:
1. A piston ring for an internal combustion engine comprising a base body of chromium steel with more than 10% chromium by weight, the base body having an inner circumferential surface, a first flank surface, a second flank surface, and an outer circumferential surface, a nitride diffusion layer with a layer thickness between 5 to 300 μm extending over the first flank surface, the second flank surface and the outer circumferential surface, the first flank surface having a nitride connecting layer with a layer thickness between 0.5 to 15 μm on the nitride diffusion layer, and an Oxide layer with a layer thickness between 0.05 to 3 μm on the nitride connecting layer, the outer circumferential surface having a chromium solid particle layer on the nitride diffusion layer, the chromium solid particle layer containing between 0.1% to 30% solid particles by volume relative to the total volume of the chromium solid particle layer.