Valve seat face surfacing technology

Abstract

The invention relates to a valve seat face surfacing technology. The technology comprises the steps of performing rough turning on a valve seat and a valve core base material of a valve to be machined through a lathe to form the rough machining size before welding; surfacing austenitic stainless steel on the rough turned valve seat and valve core base material of the valve to form a stainless steel transition layer; putting the surfaced valve seat and valve core base material of the valve on the lathe, and turning the surfaced stainless steel layer on the valve seat of the valve flat; surfacing Stellite alloy on the valve seat stainless steel surface to form a Stellite alloy layer, which is the valve seat seal face; tempering the Stellite alloy surfaced valve seat and valve core. The surfacing technology has the advantages that the austenite stainless steel layer which is high in corrosion resistance and good in material plasticity is stacked on the valve seat to serve as the transition layer, and Stellite alloy is surfaced on the transition layer, accordingly, the surfacing yield reaches more than 98%.

Description

technical field [0001] The invention relates to the field of valve manufacturing, in particular to a valve sealing surface surfacing welding process. Background technique [0002] As the sealing surface of high-temperature and high-pressure valves, a layer of Stellite alloy is generally used to weld a layer of Stellite alloy on the base metal of carbon steel, high-chromium steel, and medium-chromium-molybdenum steel. Stellite alloy has good corrosion resistance, heat resistance, and wear resistance. And high temperature anti-oxidation, anti-cavitation ability. However, the linear expansion coefficient of the Stellite alloy is different from that of the parent material. The Stellite alloy material has high strength, a small linear expansion coefficient, and poor plasticity. The two materials are combined by surfacing. Due to the large amount of heat generated during the welding process, the material expands with heat and contracts with cold. The thermal expansion coeffic...

AI Technical Summary

Problems solved by technology

However, the linear expansion coefficient of Stellite alloy is different from that of the parent material. The Stellite alloy material has high strength, small linear expansion coefficient and poor plasticity. The two materials are combined by surfacing welding.

Due to the large amount of heat generated during the welding process, the material will expand with heat and contract with cold. The thermal expansion coefficients of the two materials are different, and cracks will occur in the Stellite alloy surfacing layer, and the welding pass rate is only about 70%.