A study of residual stresses in multi-pass girth-butt welded pipes

Girth-butt welds in pipes have been widely employed in diverse applications, such as boiling water reactor piping systems, oil pipe transport systems and steam piping systems. Owing to localized heating by the welding process and subsequent rapid cooling, residual stresses can arise in the inner surfaces of the girth welded pipes. The association of residual stresses with intergranular stress corrosion cracking poses significant problems in the accurate fabrication of pipes. In this work we predict the residual stresses during multi-pass are welding in steel pipes using finite element techniques. The effects of pipe diameter and wall thickness on weld residual stresses are also discussed.