焊接工艺对Inconel 718镍铬基合金管结构环焊缝残余应力和变形影响的有限元分析

FE Analysis on Residual Stress and Deformation of Inconel 718 Ni-Cr Based Alloy Tube Structure Girth Weld Beam Under different Welding Process

采用等离子束焊(PBW)和钨极惰性气体保护焊(TIG)方法对大口径镍铬合金石油管道环焊缝进行打底焊接,采用数值模拟方法分析了两种打底焊接工艺下,焊缝及其邻近区域的温度场、残余变形和残余应力的分布。数值模拟时,根据两种焊接工艺的热源特点,选用不同的热源模型进行计算;同时考虑了材料热物理性能与温度的非线性关系,以及相变潜热对温度场的影响。结果表明,采用PBW能够得到深而窄的焊缝截面,残余应力和残余变形都比TIG打底焊缝小。

A large diameter nickel-chromium alloy oil tube was backing welded by plasma beam welding （PBW） and tungsten inert gas welding （TIG） method. The temperature field, residual deformation and residual stress distribution of the weld and its neighboring region caused by the two backing welding process were numerically simulated. During the numerical simulation, based on the characteristics of the heat source of the two welding processes, different heat source model for calculation was choosed. The nonlinear relationship of thermal physical properties and the temperature, as well as the effects of latent heat on the temperature field were studied. The results show that the deep and narrow weld cross-section can be obtained by PBW method, and the residual stress and residual deformation in PBW weld is smaller than that in TIG backing weld.