Process for mechanical plasma spray welding of sealing surface of hard alloy valve

Abstract

The invention relates to the valve manufacturing industry, in particular to a process for mechanical plasma spray welding of a sealing surface of a hard alloy valve, and mainly aims to a Y-type globe valve. According to the process, the problem of the limit to overlaying of the sealing surface and guide ribs by using other welding methods due to narrow space in a valve body is solved. The process is applied, a special device is adopted,a powder (Stellite 21) cobalt-based material is used, the welding process parameter is reasonably determined, a control program is programmed, the program is input into a device system touch screen, a spray welding device is mechanically operated, and plasma spray welding is applied to spray hard alloy powder on the positions of the sealing surface and the guide ribs of the valve body uniformly; and the use ratio of the welding materials reaches 95% or more. Spray welded enables appearance shaping to be smooth and uniform, the production efficiency is high, and the critical process work is automatically completed.

Description

technical field [0001] The invention relates to the valve manufacturing industry, and relates to the process of mechanized plasma spray welding of hard alloy valve sealing surfaces. The application of this process is mainly aimed at Y-type globe valves, and solves the problem of Y-type globe valves. Due to the narrow space in the valve body, other welding methods are limited. Weld sealing surface, guide rib. Use a special device, use powdered (Stellite 21) cobalt-based materials, reasonably determine the welding process parameters, compile the control program, input the touch screen of the device system, mechanize the operation equipment, and use plasma spray welding to uniformly spray the cemented carbide powder on the valve. On the sealing surface of the body and the position of the guide rib, the utilization rate of the welding material is as high as 95%. The appearance of spray welding is smooth and uniform, the production efficiency is high, and the key process operation...

AI Technical Summary

Problems solved by technology

[0002] In the valve manufacturing industry, the sealing surface and guide ribs in the valve body are commonly used for surfacing welding with manual electrode arc welding. Cobalt-based alloy electrodes are selected, with a diameter of Φ2.5-Φ5mm. Before use, they should be baked to the specified temperature according to the instructions of the electrodes. Only after a period of heat preservation can the sealing surface and guide ribs in the valve body be surfacing welded. Due to the narrow space and long depth in the valve body of the Y-type globe valve, manual electrode arc welding is not easy to surfacing welding, and the efficiency is low. There are many joints and it is not easy to intuitively weld the shape. Difficult to remove slag, high cost, high labor intensity, defects such as micro-cracks, pores, slag inclusions are prone to appear in the surfacing area, and it is difficult to improve the quality of surfacing welding of the sealing surface and guide rib of high-end, precision and cutting-edge valves