Abstract Scope |
Nickel (Ni) based alloys are not only widely used structural materials for current light water reactors, but also are important candidate structural materials for future advanced reactors. However, Ni based alloys are susceptible to stress corrosion cracking (SCC) in corrosive environment. During SCC, the preferential corrosion at grain boundaries (GBs) reduces their strength and thus leads to brittle intergranular fracture under tensile loads. In this work, density functional theory (DFT) modeling is used to study how the GB oxidation level, the oxygen incorporation type at GB, and GB character influence the degradation of GB strength. The atomistic modeling results are then used to inform finite-element-method (FEM) based cohesive zone modeling to study how the oxidized GBs impact the intergranular fracture propagation under tensile loads in a polycrystalline Ni. |