Local mechanical properties of a dissimilar metal welded joint in nuclear powersystems

In this paper, the local mechanical properties (yield/ultimate strength, ductility as well as stress–strain curves) of an Alloy52M dissimilar metal welded joint (DMWJ) in nuclear power systems were determined by using the mini-sized flat tensile specimens, and the local microstructures in the joint were characterized and analyzed. The results show that there are drastic variations in the local mechanical properties in the interface regions between materials. The heterogeneous mechanical properties are mainly related to the local microstructures of the DMWJ. The complex microstructures in the interface regions between materials were mainly caused by the heat flow and element migration during welding process. The local mechanical properties and their mismatches may have significant effect on crack-tip fracture mechanics parameter, plastic deformation behavior, local fracture resistance and crack growth behavior. Therefore, they need to be obtained and used in the integrity assessment of theDMWJs.