Finite element analysis of modeling residual stress distribution in all-position duplex stainless steel welded pipe

On the basis of the thermal-elastic-plastic theory, a three-dimensional finite element numerical simulation is performed on the girth welded residual stress of the duplex stainless steel pipe with ANSYS nonlinear finite element program for the first time. Three-dimensional FEM using mobile heat source for the analysis of transient temperature field and welding stress field in the circumferential joint of pipes is founded. Distributions of axial and hoop residual stresses of the joint are investigated. The axial and hoop residual stresses at the weld and weld vicinity on the inner surface of pipes are tensile, and they are gradually transferred into compressive with the increase of the departure from the weld. The axial residual stresses at the weld and weld vicinity on the outer surface of pipes are compressive while the hoop one is tensile. The distributions of residual stresses in positive-circle compared with negative-circle show distinct symmetry. These results provide the theoretical knowledge for the optimization of process and the control of welding residual stresses.