基于响应曲面方法的热冲压硼钢B1500HS淬火工艺参数优化

Optimization of Quenching Parameters for Hot Stamping Boron Steel B1500HS Based on Response Surface Methodology

超高强度钢板热冲压技术是将板料热加工和淬火工艺相结合的一项较新的复杂成形技术。为研究奥氏体化温度和保温时间对热冲压硼钢B1500HS淬火硬度、抗拉强度和伸长率的影响规律,以奥氏体化温度和保温时间为设计因子进行二因子五水平的正交试验设计。根据试验设计的结果进行B1500HS试样的淬火试验,利用洛氏硬度计和电子拉伸试验机测试试样的淬火硬度、抗拉强度和伸长率。利用三次响应曲面对试验结果进行回归分析,得到淬火硬度、抗拉强度和伸长率的响应曲面模型。根据响应曲面模型,对奥氏体化温度和保温时间进行优化,得到最佳淬火工艺参数。单目标优化结果表明:淬火硬度最高预测值为52.3 HRC;抗拉强度最高预测值为1 658.94 MPa;零件伸长率最高预测值为8.80%。多目标优化结果表明:在奥氏体化温度为916.19～920.48℃、保温时间为0 min时,淬火硬度的预测值不小于50.6 HRC,零件抗拉强度的预测值不小于1 639.98 MPa,零件伸长率的预测值不小于8.6%。

Hot stamping of ultra high-strength steels（UHSS） is a new and complex forming technology integrating metal hot forming and quenching process.In order to research the effect of austenitizing temperature and holding time on the quenching hardness,tensile strength and elongation of boron steel B1500HS,the orthogonal experiment design of two factors and five levels is carried out by using the austenitizing temperature and holding time as the design factors.Some samples of B1500HS are quenched according to the results of orthogonal experiment,the quenching hardness,tensile strength and elongation of samples are measured by using the Rockwell hardness tester and the electronic tensile testing machine.The cubic response surface models of quenching hardness,tensile strength and elongation are obtained by using the regression analysis prediction method and the results of experiment.The austenitizing temperature and holding time are optimized according to the cubic response surface model,the optimum quenching parameters are gained.The optimization results of single objective show that the predicted maximum value of quenching hardness is 52.3 HRC,the predicted maximum value of tensile strength is 1 658.94 MPa,and the predicted maximum value of elongation is about 8.80%.The optimization results of multi-objectives show that the predicted values of quenching hardness,tensile strength and elongation are not less than 50.6 HRC,1 639.98 MPa and 8.6% respectively when the austenitizing temperature is 916.19～920.48 ℃ and the holding time is 0 min.