Effect of welding residual stress redistribution on the Charpy absorbed energy

摘要

Small specimens enclosing the welded joint are cut out when inspection for the welded joint is carried out. The cutting, however, always leads to the redistribution of residual stresses developed in the original welded joint. This study investigated the difference between the primary and secondary absorbed energy of the welded joint. The primary absorbed energy is the absorbed energy when as-weld residual stress (RS) is present. The secondary absorbed energy indicates the absorbed energy when as-weld RS in the welded joint was redistributed by the wire-cutting (WC) process. Finite element (FE) simulation of the plate welding, WC, and Charpy V-notch (CVN) test was performed to examine the effect of residual stress redistribution on the absorbed energy. Results showed that the secondary absorbed energy was, on an average, 7.8 % lower than the primary absorbed energy. This difference indicates that the primary absorbed energy of the welded joint has been underestimated from the perspective of an inspector. The difference in primary and secondary absorbed energy may not be negligible when designing large welded structures such as large pipelines.