基于响应面的汽车超高强度钢淬火参数优化

Optimization of quenching parameters for automobile ultra-high strength steel based on response surface

为获得汽车超高强度钢BR1500HS淬火时最佳淬火工艺参数,采用中心复合实验进行实验设计,建立了奥氏体化温度、保温时间、冷却速率为设计变量以及淬火后的抗拉强度、伸长率和硬度为目标的二阶响应面回归模型。先通过方差分析与模型误差分析验证了模型的显著性与准确性,再通过CAGE优化工具箱对二阶响应模型进行优化求解,得到了一组最优的BR1500HS淬火工艺参数,即奥氏体化温度915.271℃、保温时间1.957 min、冷却速率35.057℃/s。最后经过实际试验,从获得的淬火后BR1500HS超高强度钢的抗拉强度为1570.8 MPa、伸长率为10.89%、硬度为54.2 HRC以及微观组织主要为马氏体,从而进一步验证了优化模型结果的可靠性。

In order to obtain optimum quenching quenching process parameters of the automobile ultra-high-strength steel BR1500HS, central composite experimental design method is applied to design the experiments. The second-order response surface regression model is built, which austenitizing temperature, holding time and cooling rate are the design variables and tensile strength, elongation and hardness after quenching are set as optimization variables. After verified the accuracy of the model by using variance analysis and model error analysis, a set of optimal BR150OHS quenching process is obtained by using CAGE optimum toolbox to optimize second-order response model, which austenitizing temperature is 915. 271%：, holding time is 1. 957 min and coaling rate is 35. 057 ~C/s. Finally, the practical test results show that the optimization model is reliable which tensile strength is 1570.8 MPa, elongation is 10.89%, hardness is 54.2 HRC and the mainly microstructure is martensite after quenching of the ultra-high strength steel of BR1500HS.