Investigation of heterogeneous ratcheting of a GTAW welded joint for primary coolant piping

摘要

Uniaxial tensile and ratcheting tests were performed with a 3D DIC system to investigate the tensile strain evolution and heterogeneous ratcheting of each area in a gas tungsten arc welding (GTAW) welded joint. The results indicated that with increasing applied stress, the strain was initially concentrated in the base metal (BM) owing to its low yield stress, and then extended gradually to the heat affected zones (HAZ) and subsequently to the weld metal (WM) until the occurrence of quasi-shakedown. Furthermore, the most remarkable ratcheting strain and ratcheting rate were obtained in the BM but it manifested lower ratcheting deformation in the BM area of the GTAW welded joint as compared with the pure base metal.