汽车转向节淬火过程温度场数值模拟、淬硬层深度预测与验证

Spindle Quenching Temperature Field Simulating and Quench Depth of Hardening Zone Forecast and Verification

本文采用ANSYS对某汽车40Cr转向节的淬火冷却过程温度场进行了数值模拟、温度场的求解，并考虑了材料热物性参数随温度的变化，得到瞬态温度场，进而对照40Cr的CCT推导组织转变，利用临界冷却速度预测了某些位置的淬硬层深度，并通过金相组织分析和硬度测试进行了验证。模拟结果和实验结果基本吻合。实测淬硬层与预测淬硬层深度相比，其值偏大；实测硬度值与预测硬度值相比，其值偏小。

Steering knuckle is a key set part of automobile driving system, so it has high demands for its strength, tough- ness and fatigue strength. Quenching is one significant factor impacting its fatigue strength . According to the heat transfer principle, the temperature field in quenching process of 40Cr steering knuckle forged parts is simulated by FEM using ANSYS software. The thermal--physical parameters of 40Cr have been considered in the thermal calculation model. The hardening depth in some locations are predicted by means of 40Cr critical cooling rate; based on CCT curve, the microhardness of differ- ent points are calculated through the hardenability curve of 40Cr. The metallographic analysis and microhardness testing was employed to test the hardening depth and microhardness. The simulation results are compared with those experimental values and there aPPears to he a good measure of agreement.