20CrMoH钢的真空低压渗碳工艺模拟及优化

Simulation and optimization of low-pressure carburizing process for 20CrMoH steel

利用真空低压渗碳软件对20CrMoH钢的渗碳过程进行模拟,并根据模拟输出在WZSTQ真空渗碳炉上进行了试验。在800 Pa压力和960℃温度下渗碳,保压25 s,对比渗碳有效硬化层深度优化工艺。结果表明,最佳渗碳时间为120 min。优化工艺后,试验测得有效硬化层深度与软件预测的深度偏差在+0.23 mm以内,满足设计要求。软件预测的有效硬化层深度更接近齿轮产品的实测深度,最小偏差为+0.10 mm。通过930℃下渗碳试验,对比表面碳含量,证明了软件预测表面碳含量为0.75%时,与实测值基本一致,最大偏差为-0.02%。

Carburizing process of 20 CrMoH steel was simulated by low pressure carburizing software, and the test was carried out on WZSTQ vacuum carburizing furnace according to the simulated output. The temperature was kept at 960 ℃, and the pressure was maintained under the carburizing pressure of 800 Pa for 25 s. The process was optimized by comparing the depth of effective carburizing hardened layer. The results show that the optimum carburizing time is 120 min. After process optimization, the deviation between the depth of effective hardened layer measured by the test and predicted by the software is within +0.23 mm, which meets the design requirements. The effective hardened layer depth predicted by the software is closer to the measured depth of the gear product, with a minimum deviation of +0.10 mm. Through the carburizing test at 930 ℃ and comparing the surface carbon content, it is proved that when the surface carbon content is 0.75% predicted by the software, it is basically consistent with the actual measured value, and the maximum deviation is-0.02%.