Study on stress measurement of large scaled welded tube

Suzuki, Hiroshi  ; Katsuyama, Jinya  ; Tobita, Toru; Morii, Yukio

Residual stress distributions near weld line of an austenitic large scaled butt-welded tube (500 mm diameter, 760 mm length and 28 mm wall thickness) were measured using the neutron diffraction technique. Typical residual stress distributions, which agreed well with some previous works using FEM, were measured in as-welded tube. After machining the slit with the size of 30 mm length, 10 mm depth and 0.5 mm width on the inside wall of the tube, the residual stresses in the axial direction were released in the part of the slit. On the other hand, the residual stress distributions after the repair welding on the outside wall were significantly changed like that tensile residual stresses were observed after the repair welding and compressive stresses were disappeared at all positions in all three directions. In this study, we indicated that the neutron diffraction technique is useful and powerful tool for measuring residual stress distribution in the large scaled mechanical components.