[目的]利用硬度和耐磨性高的碳化钨(WC)颗粒来增强高压开关液压机构阀杆表面等离子熔覆铁基涂层的耐磨性。[方法]以等离子熔覆技术在35Cr Mo钢表面制备了铁基WC复合涂层，采用光学显微镜(OM)、电子探针显微分析仪(EPMA)、X射线衍射仪(XRD)等设备考察了WC添加量对涂层组织结构的影响，测试了涂层的显微硬度和耐摩擦磨损性能，并将工艺应用在阀杆上，开展了机械寿命试验。[结果]等离子熔覆制备的铁基WC涂层组织均匀。添加质量分数15%的WC粉末可以显著提高涂层的显微硬度和耐磨性。10 000次机械寿命试验后涂覆了铁基WC涂层的阀杆无裂纹等缺陷，符合图纸要求。[结论]等离子熔覆工艺制备的Fe–WC熔覆层综合性能优异，可替代现有的镀铬工艺。

[Objective] WC particles with high hardness and wear resistance were used to improve the wear resistance of plasma-cladded Fe-based coating on the hydraulic valve stem for high-voltage switch. [Method] A Fe-based WC composite coating was prepared on 35CrMo steel by plasma cladding. The effect of the amount of WC particles on the microstructure of the coating was studied by optical microscope(OM), electron probe micro-analyzer(EPMA), and Xray diffractometer. The microhardness and frictional wear resistance of the coatings with different WC contents were tested. The mechanical life test was carried out for the valve stem plasma-cladded with the Fe–WC composite coating.[Result] The plasma-cladded Fe-based WC composite coating had uniform microstructure. The addition of 15%(mass fraction) WC particles greatly improved the microhardness and wear resistance of the Fe-based coating. There were no cracks or other defects in the Fe-based WC coating plasma-cladded on the valve stem after 10 000 cycles of mechanical life testing, which meets its performance requirements. [Conclusion] The Fe–WC composite coating prepared by plasma cladding has excellent comprehensive performance, and can be used to replace the electroplated chromium coating.