Residual stress measurements in a P92 steel-In625 superalloy metal weldment in the as-welded and after post weld heat treated conditions

• Work on dissimilar weldment of a P92 steel pipe using an In625 weld filler.
• Residual stress measurements using DHD and ND techniques in dissimilar metal welds.
• DHD-ND residual stress measurements and R6 assessment profiles comparison.
• High residual stresses found in the AW condition of the welded pipe.
• Relatively high residual stresses remain after PWHT.

Residual stress measurements have been undertaken in a multi-pass circumferential double J butt-weld made from a P92 martensitic steel pipe using an In625 superalloy weld metal. Stresses were evaluated in the as welded condition and after post weld heat treatment. The deep hole drilling and neutron diffraction techniques were used to provide through thickness measurements for the parent, weld metal and heat affected region for the as-welded and the post weld heat treated conditions. The use of multiple residual stress measurement techniques provides an understanding of the stress distributions as well as increasing confidence in the reliability of the measurements. The results presented are discussed with respect to the residual stress magnitude and location as well as with respect to the effectiveness of the post weld heat treatment procedure.