METHOD FOR MANUFACTURING PARTS OF INCREASED WEAR RESISTANCE OF THE SHUT-OFF UNIT OF A WEDGE GATE VALVE Russian patent published in 2022 - IPC B22F3/105 B33Y40/20 C23C8/38 

FIELD: valve engineering.

SUBSTANCE: invention relates to the field of valve engineering, namely to the production of shut-off pipeline valves in the form of parts of the shut-off assembly of wedge gate valves, and can be used in oil and gas, petrochemical, energy and other industries. A method for manufacturing wear-resistant parts of the shut-off assembly of a wedge gate valve made of stainless steel powder includes selective laser alloying of stainless steel powder by layer-by-layer horizontal growth with a layer thickness of 30 mcm, separation of the substrate, fine milling with a spindle rotation of 800 rpm, a cutting speed of 125 m/min. min, feed 0.03125 mm/tooth with a layer depth of 0.1 mm and lapping of the sealing surfaces of the mentioned parts. After separation of the substrate, quenching is carried out from 1040°C with holding for 30 min and cooling in oil and tempering at 480°C for 4 h with cooling in air. After fine milling, diamond burnishing is carried out with a diamond spherical indenter with a radius of 2 mm, with a burnishing force of 250 N, a burnishing speed of 10 m/min, a feed rate of 0.25 rpm and a number of working strokes of 2. Then, ion-plasma nitriding is carried out in vacuum at a temperature of 500-540°C in a nitrogen-containing gas medium discharged to 200-1000 Pa in an anomalous glow discharge. The lapping of the sealing surfaces of the mentioned parts is carried out with the provision of roughness Ra=0.09 mcm.

EFFECT: significant reduction in roughness up to 4 times and an increase in microhardness up to 3 times are provided, which makes it possible to increase the wear resistance of sealing surfaces and the service life of the locking assembly up to 4000 “closed-open” cycles.

1 cl, 2 dwg, 1 ex