哈氏合金C276管道焊接残余应力与变形的有限元分析

Finite Element Analysis of the Residual Stress and Distortion of the Welding of Hastelloy-C276 Alloy Pipes

针对哈氏合金C276焊接特点,运用有限元分析软件ABAQUS,对哈氏合金C276管道多道焊残余应力进行了有限元模拟。利用单元生死技术,模拟焊缝金属的形成;利用FORTRAN语言编写子程序DFLUX,实现了移动的高斯分布热源;考虑对流、传导、辐射以及高温下的材料性能,获得了残余应力和变形的分布规律。计算结果表明,在焊缝及热影响区,轴向拉应力对内壁裂纹的产生有主要的影响,环向拉应力对外壁裂纹的产生有主要的影响。线能量对温度和变形的影响较大,而对残余应力影响不大。

A finite element simulation was performed of the multi-pass welding residual stress of Hastelloy-C276 alloy pipes using ABAQUS software based on the welding characteristics of Hastelloy C276 alloy. The form of metal in weld seam was simulated using the unit birth-death technique; the subroutine DFLUX was compiled using FORTRAN language and the removable Gaussian distribution heat source was realized; the distribution laws of the residual stress and distortion were obtained by considering convection, conduction, radiation, and material performance under high temperature conditions. The calculation result shows that the axial tensile stress had a major influence on the generation of the internal wall cracks, and the hoop tensile stress had an influence on the generation of external wall cracks. The linear energy had a great influence on temperature and distribution, and had a little influence on residual stress.