汽车后桥螺旋伞齿轮表面缺陷分析

汽车后桥螺旋伞齿轮在经过渗碳及淬回火热处理后的磨齿过程中，其齿面出现多处细小孔洞类缺陷。利用光学显微镜、扫描电子显微镜、直读光谱仪等分析手段对齿面的细小孔洞类缺陷进行分析。结果表明:该齿轮齿面细小孔洞缺陷是由于齿圈径向截面心部整个环形区域存在着细小孔洞缺陷，因铣齿后外露造成的；而该齿轮径向截面心部整个环形区域细小孔洞缺陷则是齿圈在辗环过程中因形变过烧而引起，建议加强对锻料加热温度的控制，优化辗环工艺,并在齿圈车削加工后进行超声波探伤，尽量避免或减少缺陷产生。

Analysis of Surface Defects of Spiral Bevel Gear for Automobile Rear Axle

The spiral bevel gear of automobile rear axle was found to have many micro-hole defects in the tooth grinding process after carburizing and quenching heat treatment. Optical microscopy, scanning electron microscopy and a direct reading spectrometer were used to analyze the small-hole defects on the tooth surface. The results show that the small-hole defects on the tooth surface of the gear are due to the small-hole defects in the whole ring area of the radial section of the gear ring, which were exposed outside after the milling teeth. The small-hole defects in the whole ring region of the radial section of the gear were caused by deformation over-burning of the gear ring during the rolling process. In order to prevent such failure, it is advised that the temperature control should be strengthened and the rolling process should be optimized. In addition, ultrasonic inspection should be carried out after the turning process of the gear ring.