氧化对WC/Cu-Ni-Mn堆焊层磨损性能的影响

Influence of oxidation on wear resistance of WC/Cu-Ni-Mn surfacing layers

采用堆焊方法在钢基板表面制备WC/Cu-Ni-Mn耐磨堆焊层,通过该堆焊层的350℃下磨损性能测试及磨损表面分析,揭示其耐磨损机理。研究结果表明,耐磨堆焊层的增强相硬度(2436 HV0.2)远高于高铬铸铁堆焊层,在350℃的耐磨损性能与常温性能相比有小幅度的下降,磨损体积增加了4.95%,低于高铬铸铁堆焊层的10.88%。与常温条件下相比,350℃温度下试样的动态摩擦系数有了明显的下降,其下降的数值大约为0.1,其磨损机制还包括氧化作用,磨损表面更加光滑并且存在大量氧元素,并形成了氧化物釉质层,从而充分发挥铜镍锰基体的高温自润滑性能,有效保护了堆焊层;由于在350℃温度下软化作用会起主导作用,磨损体积反而会上升。

Surfacing welding method was carried out to fabricate WC particles reinforced Cu-Ni-Mn surfacing layer on steel substrates.Through wear performance test and wear surface analysis of the surfacing layer at 350℃,the wear mechanisms were uncovered.The research result showed that the strengthening phase of the surfacing layer appeared much better hardness(2436 HV0.2)than Fe-Cr-C surfacing layer.The wear resistance of the surfacing layer at 350℃decreased slightly compared with that at room temperature,and the wear volume increased by 4.95%,which was lower than that of Fe-Cr-C surfacing layer by 10.88%.Compared with room temperature,the dynamic friction coefficient of the sample was significantly reduced at 350℃,the value of which was about 0.1.The wear mechanism also included oxidation.The wear surface was smoother and there was a large amount of oxygen,and oxide glaze layer was formed on the wear surface.Consequently,the high temperature self-lubricating property of the Cu-Ni-Mn substrate was fully exerted,which effectively protected the surfacing layer.Since softening would play a dominant role at 350℃,the wear volume increased instead.