GH188合金热蠕变成形过程数值模拟

Numerical simulation for thermal creep forming of GH188 alloy

基于GH188合金高温拉伸和蠕变拉伸试验数据,建立了800℃高温蠕变本构方程;利用有限元软件ABAQUS建立分析模型,对双凸形构件的热蠕变成形过程进行数值模拟,分析了应力应变变化;同时,开展工艺验证试验。结果表明:蠕变应变计算值与试验值吻合较好,本构方程能够用来描述合金的高温蠕变变形;蠕变变形和应力松弛主要发生在成形的前期,优化双凸形构件的成形时间为2 h;构件曲率半径数值模拟结果与试验结果的相对误差低于15.2%,验证了有限元分析模型的合理性和有效性。

Through the high temperature tensile test and creep tensile test,creep constitutive equation of GH188 alloy was established at800 ℃. Based on the finite element analysis（ FEA） model,the thermal creep forming process of biconvex component was simulated by FEA software ABAQUS,the change of stress and strain was analyzed. Meanwhile,the process verification experiment was carried out.According to the results,calculation values and test values of creep strain are in good agreement,which indicates that the creep constitutive equation can be used to describe creep deformation of GH188 alloy under high temperature. Creep deformation and stress relaxation mainly proceed at the early stage of forming process,and the optimization time of forming biconvex component is 2 h. The relative errors of curvature radius are below 15. 2% by comparing calculation results and experimental results,thereby the rationality and the validity of FEA model are verified.