摘要
汽车变速器齿轮牙脱碳,会造成热处理后牙齿表面硬度低、表面非马氏体等不良组织,影响齿轮的接触疲劳强度和耐磨性,并易造成齿轮提前失效。以某双离合自动变速器从一挡齿轮总成精锻坯结合齿(无热前加工)为研究对象,运用金相显微镜及扫描电镜等设备,分析脱碳深度对低压真空渗碳、高压N2淬火、回火热处理齿轮表面组织的影响。结果发现:齿面全脱碳区域合金元素Mn流失,脱碳层深度对轮齿表面非马氏体组织深度有直接影响(全脱碳0.15 mm,热后齿面非马氏体组织深度0.029 mm),对次表面0.05 mm处硬度及有效硬化层深度影响不大。
Decarbonization of gear teeth in automobile transmission will result in poor surface hardness and non-martensite after heat treatment,which will affect the contact fatigue strength and wear resistance of gears,and easily lead to premature failure of gears.The effects of decarburization depth on the surface structure of low-pressure vacuum carburizing,high-pressure N2 quenching and tempering heat treatment gears were analyzed by using metallographic microscope and scanning electron microscopy.It is found that the loss of alloying elements Mn and the depth of decarburization layer have direct effect on the depth of non-martensite structure on the tooth surface(0.15 mm for decarburization causes 0.029 mm for non-martensite structure after heat treatment),but have little effect on the hardness and effective hardening layer depth at 0.05 mm on the sub-surface.
作者
楚大锋
卞凯强
曾晓蕾
CHU Dafeng;BIAN Kaiqiang;ZENG Xiaolei(Shanghai Automobile Gearworks,Shanghai 201822,China)
出处
《汽车零部件》
2019年第10期78-81,共4页
Automobile Parts
关键词
真空渗碳热处理
脱碳
合金元素
能谱
Vacuum carburizing heat treatment
Decarburization
Alloy elements
Energy spectrum
