Ti2AlNb结构件高压气淬过程数值模拟  

Numerical Simulation on High Pressure Gas Quenching Process of Ti2AlNb Workpiece

作　　者：刘晓燕[1] 张琪 杨艳慧[2] 杨西荣[1] 高飞龙 Liu Xiaoyan;Zhang Qi;Yang Yanhui;Yang Xirong;Gao Feilong(School of Metallurgical Engineering,Xi’an University of Architecture and Technology,Xi’an 710055,China;School of Materials Science and Engineering,Northwestern Polytechnical University,Xi’an 710072,China)

机构地区：[1]西安建筑科技大学冶金工程学院,陕西西安710055 [2]西北工业大学材料学院,陕西西安710072

出　　处：《稀有金属材料与工程》2022年第1期149-158,共10页Rare Metal Materials and Engineering

基　　金：国家自然科学基金(51474170);陕西省教育厅重点实验室项目(20JS075)。

摘　　要：高压气淬过程中,由于冷却速率较大,工件易产生热应力,甚至发生塑性变形或开裂,因此能准确预测高压气淬过程中工件热应力分布对于工业生产尤为重要。本研究运用计算流体力学法建立了交流流动型立式高压气淬炉气淬过程的数值传热和湍流模型,模拟了Ti2AlNb超塑成形/扩散连接空心结构件的气淬过程,并通过间接耦合法得到Ti2AlNb结构件气淬过程应力场。采用有限体积法划分了简化炉模型的网格,并根据实际工况设定了边界条件。模拟结果显示,Ti2AlNb空心结构件在气淬开始时四周边缘冷却较快,心部冷却较慢,随着时间的增加,两侧冷却较快,心部冷却较慢。温度的分布决定了热应力的分布,Ti2AlNb结构件心部温度高,边部温度低,心部受边部的限制不能自由膨胀,因此心部受压应力。气淬过程中热应力未超过屈服强度,均属于弹性范围。Due to the large cooling rate, the workpiece often produces thermal stress during the high pressure gas quenching process, and even plastic deformation or cracking occur. Therefore, it is particularly important for industrial production to accurately predict the thermal stress distribution of the workpiece during the high pressure gas quenching process. In this study, the numerical heat transfer and turbulence model of an exchange flow type vertical high pressure gas quenching furnace was established using computational fluid dynamics method, to simulate the gas quenching process of a Ti2 AlNb hollow workpiece processed by superplastic forming/diffusion bonding, and the thermal stress distribution of Ti2 AlNb workpiece during gas quenching was calculated by indirect coupling method. The mesh of simplified furnace model was built using finite volume method and the boundary conditions were set according to the actual working conditions. The simulation results show that at the beginning of gas quenching, the edges around the Ti2 AlNb workpiece cool faster than the core. As time increases, the both sides cool faster than the core. The temperature distribution determines the thermal stress distribution. Ti2 AlNb workpiece has a high temperature in the core and low temperature at the edges, which causes the core to be restricted by the edges and cannot expand freely, so the core is under compressive stress. During the gas quenching process, the thermal stress does not exceed the yield strength, which belongs to the elastic range.

关 键 词：高压气淬 计算流体力学 温度场 热应力场 

分 类 号：TG156.34[金属学及工艺—热处理] TG146.23[金属学及工艺—金属学]