扶梯变速齿轮感应回火工艺研究

研究了某扶梯变速齿轮的3种不同感应回火工艺,并与传统回火工艺进行了对比。通过分析硬度分布、微观组织以及回火后的残余应力分布,对上述几种工艺进行了评估。结果显示,感应回火次数对硬度、组织及残余应力分布的影响较大。相比单次感应回火工艺,采用传统回火工艺后的齿面和齿根硬度分布较均匀。同时,通过采用多次感应回火工艺能够有效提高硬度分布均匀性,并得到细小的回火马氏体组织,且在齿轮表面形成较小压应力,有利于提高齿轮的韧性和疲劳强度。此外,针对典型的感应回火和传统回火工艺,进行了弯曲疲劳试验,验证了感应回火工艺的可行性。

Study on Induction Tempering Technology of Escalator Change Gear

Study on three different induction tempering processes for a certain kind of change gear are carried out,and the results are compared with that of the traditional furnace tempering process. By contrastive analysis of the hardness distribution,microstructure,and also the residual stress distribution after tempering,all the above tempering processes are evaluated. The results show that the heating times of induction tempering has significant effects on hardness distribution,microstructure and residual stress. Compared to the single-pass induction tempering,the hardness distribution at the surface and root of the tooth was more uniform. Besides,multi-pass induction tempering could obviously improve the hardness uniformity,form fine tempered martensite structure and compressive residual stress at the tooth surface,which would help improve the toughness and fatigue strength of the gear. Furthermore,fatigue bending test is carried out to verify the feasibility of the induction tempering process.