X-Ray Study of Residual Stresses in Narrow Groove TIG Weldments. Final Technical Report, September 1979-March 1984

摘要

The residual stresses measured in this project in the plane of the plate rolling surface, in the heat-affected zone, adjacent and in a direction normal to the weld fusion line, are greater than those in a direction parallel to the weld fusion line. This is in contradiction to the observation that in single-pass welds the parallel stresses are greater. The maximum residual stresses observed in the weldment studied were nearly or at the yield strength; this stress level is comparable with that shown in welds from thin plates, but no greater; and was at the weld fusion line, or toe, of the weld. A double peak in the plots of stresses normal to the weld line on traverses normal to the weld on the rolled surface of the original plate was attributed to hardenability variation caused by the thermal cycling during multi-pass welding. The stress field of the narrow groove weldment is less extensive than what was predicted for V groove. Stress relief due to cutting the weldment through a plane normal to the weld line caused relief as far as 40% of the plate thickness. The weld repair caused severe perturbations to residual stress symmetry of the weldment. (ERA citation 10:018645)