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

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.