Residual stress characterization of welded specimens by non-destructive activation technique

Welded specimens consisting of Type 304L stainless steel and/or Alloy EP-823 were tested for evaluations of the extent and nature of resultant residual stress in terms of line-shape parameters based on the activation technique associated with positron annihilation spectroscopy. A maximum residual stress was estimated near the welded region of specimens of similar and dissimilar materials. It is suggested that the compressive residual stress in the vicinity of the fusion line of Alloy EP-823 side of the welded specimen may be attributed to the volume increase and plastic strain developed during its rapid cooling and solidification.