Measurements and Simulations of Weld Residual Stresses for Feeder Dissimilar Metal Welds

Abstract

In CANDU nuclear power plants, dissimilar metal welds (DMWs) are present in some of the feeders. PWR operating experience and research suggest that such dissimilar metal welds on outlet feeders may be susceptible to primary water stress corrosion cracking (PWSCC) especially at the welding start/stop locations. In this paper, a finite element method (FEM) approach has been developed through an ABAQUS user subroutine to predict welding residual stress (WRS) in DMWs. Measurement results from the X-ray diffraction and the contour methods are adopted to validate the WRS prediction. Sensitivity studies on the effect of work hardening and annealing on WRS prediction are also investigated. The predicted WRS will be applied as inputs to the natural crack growth analysis to demonstrate the crack stability in the near future.