轿车手动变速器齿轮齿顶非马氏体组织的成因分析与解决

The analysis and solution of non-martensite microstructure in MT gear tooth tips

本文主要针对某项目从动五档齿轮经过低压真空渗碳、高压气体淬火工艺热处理后,齿顶出现非马氏体组织的成因进行分析,试验发现,表面碳浓度偏高及淬火时冷却能力不足是导致齿顶出现非马氏体的主要原因。通过有针对性地调整渗碳节拍、淬火的气体压力、搅拌速度、时间等参数,经过多次验证,从根本上解决了齿顶组织异常问题。

Non-martensite microstructure appears at the tooth tip area abnormally after the LPC HT testing for GEAR 5th. The experiment found the major reason is the high carbon concentration of tooth surface and insufficient cooling strategy. The tooth tip problem of this abnormal microstructure was essentially resolved through making a series of specific modifications on carburizing timing, gas quenching parameter, gas pressure, rotate speed and cycle time.