PISTON RING WITH CHROMIUM AND SOLID PARTICLES LAYER TO PROTECT FROM WEAR AND CORRSION RESISTANT SIDE FACE Russian patent published in 2017 - IPC C23C28/00 F16J9/26 C25D3/04 C23C8/26 

FIELD: machine engineering.

SUBSTANCE: piston ring contains a major part of the chromium steel with more than 10% by the chromium weight, having the inner peripheral surface, the first side surface, the second side surface and the outer peripheral surface. At the first side surface it contains the nitrided diffusion layer with thickness of 5-300 micron, the nitrided bond layer with thickness of 0.5-15 microns located directly above it, and the oxide layer with thickness of 0.05-3 microns located directly above it. On the second side surface it contains a nitrided diffusion layer. On the outer peripheral surface it contains the nitrided diffusion layer and the chromium and solid particles layer located above it, wherein the solid particles volume content is 0.1-30% relatively to the total volume of the indicated layer. The method of the indicated piston ring manufacture, wherein the metal major part of the piston ring, having the inner peripheral surface, the first side surface, the second side surface and the outer peripheral surface, is subjected to a combined process of nitration-oxidation in the atmosphere, containing at least one nitrogen compound, with heating at least up to 300°C. Then the air is supplied and the piston ring is cooled in the air presence. As a result, the nitrided diffusion layer, located above it the nitrided bond layer, and located above it the oxide layer is obtained at least at the first side surface, the second side surface and the outer peripheral surface. The piston ring is placed into the aqueous electrolyte, containing chromium in the ionic form and the solid particles, and the layer of chromium and mentioned solid particles is electrochemically deposited at least to the outer peripheral surface.

EFFECT: obtaining the piston ring with high wear-resistant outer peripheral surface and the side surface, which has both high hardness and high corrosion resistance.

15 cl 3 dwg