PLUG OF PRESSURE-BALANCE OIL SEAL PLUG VALVE AND PLUG SURFACE TREATMENT PROCESS

摘要

　A treatment process for the surface of a plug of a pressure-balance oil seal plug valve used in an oil-gas pipeline and a plug obtained by the process, wherein the plug surface (5) is provided with a first hardening layer (1) of a thickness of 1.5-5 mm, a second hardening layer (2) of a thickness of 0.13-0.17 mm and a self-lubrication wear-resistant layer (3) of a thickness of 0.01-0.03 mm in succession from inside to outside, which are obtained by a carburization process, a QPQ salt bath composite treatment process and a PTFE spraying process, respectively. The thickness of the first hardening layer (1) is relatively thick, which facilitates the anti-erosion capacity of the plug; the second hardening layer (2) further improves the hardness of the plug surface (5), and greatly improves the anti-abrasion capacity of the plug; the self-lubrication wear-resistant layer (3) greatly reduces the porosity of the plug surface (5), and facilitates the valve sealing, such that the metal of the plug and the metal of a valve body are disengaged, reducing the torque of the valve and increasing the integral cost performance of the valve.