Hydride corrosion kinetics on metallic surface: a multiphase-field modeling

The hydride growth on metallic surface can cause material failure, which is a significant form of pitting corrosion. A new multiphase-field model constructed to study the corrosion kinetics, in three order parameters are introduced represent passive film, and metal phase, respectively. Coupling with hydrogen concentration field elastic strain field, this not only presents rupture but also reveals diffusion mechanism effect energy process. simulation shows semi-ellipsoidal cerium forms grows near film/cerium interface. During process, film upper side hydrogenated or peeled off, resulting faster transport, turn promotes hydride. formation causes volume expansion, mainly distributed around hydride, inhibits its growth. present contributes understanding at mesoscale, especially kinetics rare earth metals.