Effect of welding sequence on residual stress distribution in a multipass welded piping branch junction

This paper presents a validated three-dimensional thermomechanical model to investigate the effect of the welding sequence on weld induced residual stress distributions in a multipass welded piping branch junction. Three possible symmetrical welding sequences, i.e. one-welder, two-welder and four-welder sequence, which were expected to generate the least adverse stress distributions in actual welding circumstances, were proposed and evaluated. It is shown that the variations of the predicted maximum stresses along the fusion lines are not large for the three proposed welding sequences, although at both the branch and run cross section, the four-welder model predicts the highest peak residual stresses while the one-welder model gives the lowest values. As would be expected, the stress distributions predicted by the four-welder and two-welder models show more symmetrical features than those by the one-welder model. High residual stress is formed in the vicinity of the weld region irrespective of the sequence of the welding.

► We studied welding sequences for fabricating a thick-walled piping branch junction.
► We investigated welding sequence effect on residual stress in the above component.
► Geometrical restraint governs residual stress profiles in the component.
► Welding sequence has less effect on the maximum residual stress than cooling rate.
► We report weak dependence of residual stress on welding sequence for the component.