Modeling of hydrogen embrittlement in single crystal Ni

A large-scale molecular dynamics simulation by the embedded atom method was carried out on hydrogen embrittlement of a single crystal containing 1,021,563 nickel atoms. The details of the deformation in the specimen were identified by a new method of the deformation analysis. Plenty of slip deformation occurred around the crack tip and in the bulk of the hydrogen-free specimen. Hydrogen embrittlement was most serious in the specimen hydrogen-charged in the notched area. Serious embrittlement was also observed in the specimen hydrogen-charged in the slip planes, in which dislocation emission was localized at the crack tip and enhanced on the planes where hydrogen atoms were located. It is considered that the fracture process is due to the hydrogen-enhanced decohesion mechanism.