2024铝合金薄壁板材淬火过程建模仿真

Modeling and simulation of quenching process of 2024 aluminum alloy thin-wall sheet

针对2024铝合金薄壁零件易产生严重的淬火扭曲变形的问题,利用有限元分析和实验验证的手段,考虑淬火介质(水)相变及试件浸入过程对热交换的影响,对淬火过程中零件与介质的换热过程进行了研究。结果表明,相比不考虑浸入的淬火过程,有浸入过程的淬火试件的温度场变化梯度较大,导致试件发生较大的变形,与实验结果吻合。考虑介质(水)相变时,初始阶段水蒸汽的产生抑制了换热速率,但随着淬火的进行,水蒸汽气泡会将热量快速带走,增加了换热速率,导致两种情况下的换热系数存在较大的差异。

Aiming at the problem that the serious quenching distortion deformation is easy to occur for 2024 aluminum alloy thin-wall part,by means of finite element analysis and experimental verification,and considering the influence of phase transformation of quenching agent( water) and immersion process of test piece on heat transfer,the heat transfer process between parts and quenching agent in quenching process was studied. The results show that compared with the quenching process without considering immersion,the changing gradient of temperature field of specimen quenched with immersion process is larger,which leads to a large deformation of the specimen.This result is consistent with the experimental results. The heat transfer rate is inhibited by the generation of water vapor in the initial stage when the agent( water) phase transformation is considered. But as the quenching process proceeds,the water vapor bubbles take away the heat quickly and increase the heat transfer rate,which causes a big difference of the heat transfer coefficient under the two conditions.