Fracture mechanism of cracks in the weakest location of dissimilar metal welded joint under the interaction effect of in-plane and out-of-plane constraints

This paper systematically studies the fracture mechanism of cracks located in the weakest location of Alloy52M dissimilar metal welded joint (DMWJ) in nuclear power plants under the interaction effect of in-plane and out-of-plane constraints. The J-resistance curves and fracture mechanism of all specimens were analyzed and compared in detail. The results show that for the specimen with low in-plane constraint and low out-of-plane constraint, the fracture mechanism is highly ductile fracture, and the J-resistance curve is high. For the specimen with low in-plane constraint and high out-of-plane constraint, local brittle fracture occurs, but the fracture mechanism is dominated by the ductile fracture, and the J-resistance curve is high. For the specimen with high in-plane constraint and low out-of-plane constraint, the fracture mechanism is mixed brittle and ductile fracture, and the J-resistance curve is low. For the specimen with high in-plane constraint and high out-of-plane constraint, the fracture mechanism is dominated by the brittle fracture, but local ductile fracture is also present, and the J-resistance curve is low.