双相不锈钢管道焊接残余应力参数的数值模拟

焊接残余应力一直为人们所关注，其大小和分布与焊接热源、接头形式和材料性能等多种因素有关，作者利用热弹塑性理论为基础的有限元数值模拟技术，对SAF2205双相不锈铜管道接头环焊缝残余应力进行有限元数值模拟，得到了管道内外表面残余应力的分布规律，即，在管道的焊缝及近缝区，内表面轴向残余应力是拉伸应力，外表面轴向残余应力是压缩应力，而内外表面环向残余应力都是拉应力；研究了不同的焊接线能量、管内径与壁厚比值R1／d和多层焊对焊接残余应力的影响，结果表明，残余应力受焊接能量变化的影响不大，外表面残余应力和内表面轴向残余应力部随着壁厚增大而增大，多层焊的残余应力有不同程度降低。

Numerical Simulation of Parameter of Residual Stresses on Butt-Welded Duplex Stainless Steel Pipes

The problem of the welding residual stresses always draw wide attention.The distribution and magnitude of residual stresses relate to several factors such as thermal source,joint shape and material property,etc.In this paper,circumferential bett-welding of SAF2205 duplex stainless steel pipe was simulated numerically based on a non-linear thermo-mechanical finite element-analysis.The residual stress distributions were obtained.The axial and the hoop residual stresses at the weld and weld vicinity on inner surface of pipes are tensile,while those on outer surface of pipes are compressive and the hoop one is tensil.Effects of weld line energy,ratio of inner radius to wall thickness and multi-pass weld on residual stresses were further investigated.The results show that the line energy has small influence upon the residual stresses within practical applications.The thicker walled pipes have more residual axial stress and a larger zone of tensile stress.Compared with single pass,the peak value of residual stress by multi-pass welding decreases to different extent.