磁场作用下镍基等离子弧堆焊层的组织及耐磨性能
Microstructures and wear resistance of Ni-based PLA surfacing layer with introducing magnetic field
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摘要: 采用等离子弧堆焊设备将镍基合金粉末堆焊到低碳钢表面的过程中施加直流横向磁场,此后对堆焊层进行硬度、磨损和金相试验以及EDS,XRD分析,并系统地研究直流横向磁场对镍基粉末等离子弧堆焊层组织及耐磨性能、硬质相形态及数量的影响规律,对直流横向磁场的作用机理进行了初步的分析和讨论.结果表明,堆焊电流和磁场电流相匹配,即堆焊电流为140 A和磁场电流为2 A时,堆焊层才能获得最佳的性能,此时堆焊层的硬度为66.3 HRC,磨损量为0.0767 g,并且堆焊层组织中硬质相数量最多且分布均匀,从而增强了堆焊层金属的综合力学性能.Abstract: Ni-based alloy was surfaced on low-carbon steel by plasma arc surfacing under DC transverse magnetic field.The hardness,wear resistance,microstructure and phase constitution of the surfacing layers were investigated via hardness and wear tests as well as SEM,EDS and XRD analysis.The influence of DC transverse magnetic field on the microstructures and wear resistance of the surfacing layer,the shape and amount of the hard phase were systematically studied.Furthermore,preliminary analysis and discussion of the DC transverse magnetic field mechanism were made.The results show that the optimal properties are obtained when surfacing current and magnetic field current matches properly.When the surfacing current is 140 A and the magnetic field current is 2 A,the hardness and the wear loss of surfacing layer are 66.3 HRC and 0.0767 g,separately.At the point,the amount of hard phase is the most and the distribution of hard phase is even,the comprehensive mechanical properties of surfacing layer are enhanced.