模具间隙对高强度钢热冲压过程的影响

利用DEFORM软件,建立了不等模具间隙下高强度钢板热冲压的有限元模型,研究了模具间隙对22Mn B5钢板热冲压成形中温度场以及马氏体转变的影响规律。数值模拟结果表明:模具间隙是影响板料温度变化的主要因素,板料的最大温差随着模具间隙先增大后减小;模具间隙为0.95t~1.00t时,板料各部位的马氏体分布均匀,转变率高。在此基础上,进行了热冲压试验,测试了板料侧壁位置点和底部圆角位置点的温度变化,并观察了板料成形后的微观组织,通过试验结果与数值模拟结果一致性对比,验证了数值模拟结果的可靠性与准确性。

Influence of die clearance on hot stamping process for high strength steel

A finite element model of the hot stamping for high strength steel was established under different die clearances by DEFORM software, and the influences of die clearances on temperature field and martensite transformation of steel sheet 22MnB5 were studied. The numerical simulation results indicate that the die clearance is the main factor influencing the temperature change of part, and the maximum temperature difference of part increases with the increase of die clearance and then decreases. Furthermore, the martensite in every part of sheet is homogenously generated and has a higher transformation rate while the die clearance is 0. 95t-1. 00t. Therefore, the hot stamping experiment was executed based on the numerical simulation results, and the temperature changes in the position of sidewall and bottom corner of part were tested. Finally, the microstructures of sheet were observed, a good agreement between numerical simulation and exper-imental results was verified, and the reliability and validity of numerical simulation results were verified.