焊接转子热处理过程中残余应力释放行为数值研究

基于ABAQUS有限元分析软件,编写DFLUX、FILM和UEXPAN子程序,建立焊接转子模拟件(M-1)和全尺寸焊接转子(M-2)轴对称有限元模型,实现了采用双椭球移动热源模型和考虑固态相变的转子焊接仿真过程。纳入Norton-Bailey蠕变本构方程研究了热处理过程中残余应力在不同热处理参数下的应力松弛行为。结果表明：焊接转子模拟件能够较为准确地反映全尺寸焊接转子焊接残余应力分布状态；考虑固态相变的焊接仿真结果更接近于实验测量值；热处理参数对残余应力释放行为影响不尽相同,其中热处理温度是决定热处理效果的关键因素。

Numerical study on the welding residual stress relaxation behavior in welded rotor during PWHT

Based on the ABAQUS commercial finite analysis software, the subroutines of DFLUX, FILM and UEXPAN were complied, and two axisymmetric finite element models including the experiment pipe model (the M-1 model) and the whole welded rotor model (the M-2 model) were employed to simulate the welding process subjected to a moving double ellipsoid heat source; Besides, the post-weld heat treatment (PWHT) processes with different parameters by considering Norton-Bailey creep constitutive equation were conducted to investigate the welding residual stress relaxation behavior. The results show that: the distribution of welding residual stress in the M-1 model is similar to that in the M-2 model; and the distribution of welding residual stress considering solid-state phase transformation is more consistent with the experimental data; the residual stress relaxation behaviors during different stages in PWHT are also different, and the PWHT temperature has an obvious influence on the final distribution of residual stress.