余热淬火循环泵数量对锻造转向节内部组织的影响

针对汽车转向节余热淬火容易出现淬火裂纹等质量问题,以江淮瑞风汽车转向节的余热淬火试验为例,通过启动一台和启动两台淬火介质循环搅拌泵,检测转向节在不同工况下的硬度剖面梯度、金相组织、晶粒度等级参数,并分别对其进行现场试验研究。通过分析热淬火油槽内循环搅拌泵的开启数量对转向节内部组织的影响,可知在温度和介质冷却特性不变时,循环搅拌泵开启台数对淬透层深度有明显的影响。并证明了开启两台循环搅拌泵是最佳选择,同时使用两台循环搅拌泵,既能保证冷却均匀性,又能提高锻件整体淬火硬度,还能提高金相组织级别。

Influence of quantity of residual heat quenching circulating pump on internal organization for forging steering knuckle

For the quenching crack and other quality problems caused by residual heat quenching of automobile steering knuckles,taking the residual heat quenching test of automobile steering knuckle for Refine,JAC as an example,the parameters of hardness profile gradient,metallographic structure and grain size grade for steering knuckle were detected under different working conditions by starting one or two quenching medium circulating stirring pumps. And the field tests were conducted on them respectively. By analyzing the influence of opening number for circulating stirring pumps in the hot quenched oil tank on the internal structure of steering knuckles,it is found that the opening number of circulating stirring pumps has a significant influence on the depth of quenched layer when the temperature and cooling characteristics of medium remain unchanged. Then,it is proved that it is the best choice to open two circulating stirring pumps. Using two circulating stirring pumps simultaneously can not only ensure the cooling uniformity,but also improve the overall quenching hardness of forgings and the level of metallographic structure.