车轴用钢EA1N表面等离子熔覆铁基合金熔覆层组织与性能研究

Microstructure and Properties of Plasma Cladding Fe-based Alloy Coatings on Axle Steel EA1N

采用等离子熔覆技术在EA1N车轴用钢表面制备铁基合金熔覆层,目的是提高车轴用钢EA1N表面的硬度以及耐磨性能,通过光学显微镜、X射线衍射仪、SEM扫描电镜对熔覆层及基体的显微组织结构及物相组成进行表征显微硬度及耐磨性分析。结果表明,熔覆层组织为奥氏体亚共晶组织和碳化物;熔覆层与基体间有一条明显的白亮带,说明基体与熔覆层结合效果较好,达到了冶金结合;热影响区组织为针状马氏体是因为靠近熔覆层基体受热后导致基体组织发生转变相当于淬火处理,基体组织为珠光体和铁素体。再利用显微硬度计以及摩擦磨损试验机在相同条件下对熔覆层和基体的硬度以及耐磨性进行测试,结果表明,熔覆层硬度602.6HV0.2高于基体材料的硬度200.8HV0.2,熔覆层的耐磨性也优于基体材料。

The iron-based alloy cladding layer was prepared on the surface of EA1Nsteel by plasma cladding technology in order to improve the hardness and wear resistance of the substrate surface.The microstructure,phase composition,microhardness and friction and wear of the cladding layer were analyzed by X-ray diffractometer,SEM scanning electron microscope,EDS,microhardness tester and friction and wear tester.The results show that the microstructure of the cladding layer is austenite hypoeutectic structure and carbides,and there is an obvious bright white band between the cladding layer and the heat-affected zone,indicating that the matrix and the cladding layer are metallurgically bonded,and the heat-affected zone is acicular.Tensite,the matrix structure is pearlite and ferrite.Under the same conditions,the hardness of the cladding layer is 602.6HV0.2higher than that of the base material,which is 200.8HV0.2,and the wear resistance of the cladding layer is also better than that of the base material.