以Fe-1.8Ni-0.5Mo-1.2Cu-0.2C预合金粉为原料, 采用温压、烧结、渗碳、淬火与低温回火的工艺制备了粉末冶金齿轮, 利用光学显微镜、扫描电子显微镜和硬度仪等研究了齿轮的组织与性能。结果表明: 温压压坯的密度为7.35 g·cm-3, 相对密度为94.2%; 烧结态齿轮的显微组织主要是珠光体和铁素体, 硬度达到46~54 HRA, 密度为7.37 g·cm-3, 相对密度为94.5%, 烧结态齿轮有轻微收缩现象, 但其仍表现出良好的尺寸稳定性; 热处理后齿轮渗碳层的组织主要由回火马氏体和少量残余奥氏体组成, 齿轮断齿扳力为9.6 kN, 硬度提高至66~75 HRA。

Taking Fe-1.8Ni-0.5Mo-1.2Cu-0.2C pre-alloy powder as raw material, a powder metallurgy gear was prepared by warm compaction, sintering, carburizing, quenching and low temperature tempering technologies. The microstructure and properties of the gear were studied by optical microscopy, scanning electron microscopy and hardness testing, etc. The results show that the warm compaction green density was 7.35 g·cm-3 and relative density was 94.2%. The microstructure of sintered gear mainly was pearlite and ferrite, the hardness, density, relative density of the sintered gear was 46-54 HRA, 7.37 g·cm-3 and 94.5%, respectively. The slight shrinkage of sintered gear was found, but it still kept good dimensional stability. The microstructure of carburized layer after heat treatment mainly was tempered martensite and small amounts of retained austenite, and the teeth mechanical resistance was 9.6 kN and the hardness was increased to 66-75 HRA.