高强度硼钢22MnB5的热变形方程及其模拟应用

利用Gleeble-3500热模拟试验机,在温度为700℃～950℃、应变速率为0.01/s～0.4/s的条件下,对高强度硼钢22MnB5的热变形行为进行研究。结果表明,随着变形温度的升高,硼钢的延伸率升高,变形抗力降低;随着应变速率的提高,硼钢22MnB5的变形抗力和延伸率增大。根据高温拉伸实验得出的数据,构建硼钢22MnB5的稳态流变应力模型和热变形方程,并将试验结果和构建的本构方程输入ABAQUS软件进行U型件热弯曲成形的回弹模拟,数值模拟结果与实验结果吻合较好,验证了模型的可靠性和正确性,为成形所需的最大载荷及设备选择提供依据。

Hot deformation equation for boron steel 22MnB5 and its application in simulation

According to the time-temperature characteristic of hot stamping,the hot deformation behavior of boron steel 22MnB5 was studied with a compression test by using Gleeble3500 simulator at temperature 700℃～950℃ and strain rate 0.01s～0.4/s.Results show that with increasing temperature,the elongation of 22MnB5 increases and the deformation resistance decreases;with increasing strain rate,the elongation and the deformation resistance of 22MnB5 both increase.The deformation activation energy,the relationship between the peek stress with the deformed temperature and strain rate were calculated.Based on the Zener-Hollomon parameter,the steady flow stress model and hot deformation equation for boron steel 22MnB5 were proposed.The springback of U-bending forming simulation had been done in the finite element software ABAQUS.Results of simulation are in good agreement with those of experiments.All these provide reference for the manufacturing process of hot forming.