Some Experimental Studies to the Residual Stresses of the Welded Pipes

Abstract

We studied the distributions of residual stresses of the seam-welded and circumferentially welded pipes, changing the welding sequence such as shown in Fig. 2. The results of our experiment were shown in Fig. 3-Fig. 6. To compare these results, we adopted the maximum value of the stress, equivalent stress (σ_eq) defined by the eq. (1) and the triaxiality ratio (Tr) defined by the eq. (3). Fig. 11-Fig. 14 show these values of each specimens.
Generally speaking, the residual stress distributions in the seam-welded pipes are nearly the same as in the butt welded plate, but the stress distributions of the circumferentially welded pipes are not the same as in the butt welded plate. As shown in Fig. 9, effects of bending moment can be considered in the latter cases.