Estimation of residual stresses in an 800 mm thick steel submerged arc weldment

Abstract Assuming plane strain conditions and taking phase transformations into account, finite element analysis was carried out using a bead-by-bead deposition model as well as two different lumped models. The effects of post-weld heat treatment at 600 °C were also studied. Predicted residual stresses were verified using X-ray diffraction method. While both bead-by-bead and lumped models were found to overestimate the maximum residual stress in as-welded condition, the latter facilitated a safer upper-bound estimate of the residual stress. The net tensile stress in the weld metal was found to decrease as a result of solid-state transformation of austenite to ferrite. Further, a significant part of stress relief was found to occur in the first half hour of the holding time during post-weld heat treatment. A formula was developed for estimating the maximum residual stress in post-weld heat treated condition.