Atomistic simulations of stress corrosion cracking

Stress corrosion cracking (SCC) of stainless steels and nickel alloys in pressurised water reactors (PWR) has been studied for many years but the mechanism at atomic scale is still under debate. The purpose of this paper is to use atomistic calculations, molecular statics (MS) to describe the sequence of phenomena occurring at the crack tip of an SCC fracture. MS simulations with EAM potentials have been carried out on Ni bicrystals containing hydrogen. The calculations show that compression force applied on the crack lips with H at the GB causes brittle rupture. A theoretical model of SCC cracking has been proposed which fits particularly SCC of irradiated stainless steels (IASCC).