以Inconel 625镍基合金管道的焊接接头为研究对象，建立了热-力学耦合的三维有限元模型，采用ANSYS软件对该合金管道环焊缝对称焊的残余应力进行了数值模拟，分析了管道外表面轴向和环向残余应力分布，并进行了试验验证；此外，还分析了预热温度对管道残余应力的影响。结果表明：该合金管道焊后外表面轴向与环向残余应力的模拟结果与试验结果在数值和分布趋势上均比较吻合，证明了模型的准确性；在焊缝及近焊缝区的管道外表面形成了轴向压应力和环向拉应力，随着距焊缝中心距离的增加，轴向压应力逐渐变为拉应力，而环向拉应力逐渐转变为压应力，并最终趋向于0；随着预热温度的升高，管道外表面轴向和环向残余应力均降低。

Based on the butt joint of Inconel 625 nickel-based alloy tube, the three-dimensional thermal and mechanical finite element model was established. The ANSYS software was used to simulate the residual stress of the nickel-based alloy tube after girth welded by the symmetry welding method, and the simulated distribution of axial and hoop residual stress on outer surface of the tube were analyzed and verified by experiment. In addition, the effect of the preheating temperatures on the residual stresses was investigated. The results show that the axial and hoop residual stress distribution on outer surface of the tube obtained by simulation coincided well with the experimental results, indicating the accuracy of the simulation model. The axial residual compressive stresses and hoop residual tensile stresses formed on outer surface of the weld and near weld zone. With the increase of the distance from the weld center line, the axial compressive stress gradually turned to tensile stress and hoop tensile stress to compressive stress, and then tended to zero. The axial and hoop residual stresses both decreased with the increase of the preheating temperature.