桑车齿轮锻造余热等温退火工艺研究

对于Cr-Mn系桑车变速箱齿轮而言，锻后常规正火常见的弊病之一是形成粒状贝氏体，致使切削加工困难以及最终热处理变形趋于无规律。本文从提高生产率和节能出发，研究了桑车齿轮锻造余热等温退火工艺。研究表明，对于16MnCr5钢齿坯，通过控制锻后冷却速度、冷却时间和采用适当的等温温度和等温时间，可获得所需的硬度和组织，齿坯的切削性能及变形均能满足要求。该工艺具有良好的稳定性和重现性，并有显著的节能效果。

Study on Insothermal Annealing Process by Use of Residual Forging Heat for the Gears in the Santana Car

One of the common defects in Cr-Mn steels for the Santana Car speed box gears after forging and usual normalizing is the production of granular bainite,and as a result,the gear cutting will become difficult and their distortion arised from final heat treating tends toward unconstant variation.For the sake of energy-saving and productivity rising,isothermal annealing by use of residual forging heat of the gears for the Santana car has been studied in this paper.The research results show that hardness and structure required for the gear blanks can be obtained by means of the control of cooling rate and cooling time as well as isothermal temperature and time.The cutability and degree of distortion of the gear blanks have fulfilled all the requirements.The annealing process has possessed better stability and reproducibility and achieved obvious effect of energy-saving.