Measuring and modelling residual stresses in a butt-welded P91 steel pipe

Residual stresses in a circumferentially butt-welded steel pipe have been measured and numerically predicted. The pipe, containing the circumferential weld, has an outer diameter of 290 mm and a wall thickness of 55 mm, typical of components in power generation plants. Residual stresses have been measured using the X-ray diffraction and deep-hole drilling techniques. Good correlation has been demonstrated with the predictions of an axisymmetric thermo-mechanical finite element model. The paper demonstrates that a mixed experimental and numerical approach is useful for determining the residual stress distribution in welded joints.