Hydrogen Concentration Effect on the Plastic Deformation of α-Fe by Molecular Dynamics Simulation
The effect of hydrogen concentration on plastic deformation inside polycrystalline α-Fe under cycle loading is investigated by molecular dynamics(MD)simulations.Ovito is applied to observe the interaction of hydrogen with dislocations,grain boundaries,and vacancies.The number of vacancies in the model is calculated by the Wigner-Seitz cell method.The results prove that dislocation generation,and emission are enhanced in the { 110}<111>slip system and suppressed in the other slip systems by atomic hydrogen concentration.There is a critical hydrogen concentration below which hydrogen atoms promote plastic deformation,beyond which the plastic deformation is hindered.The number of vacancies and the stress intensity increase with hydrogen concentration and the number of loading cycles.Moreover,the generation of vacancies is less affected by cycle loading than by the hydrogen concentration.It reveals the critical hydrogen concentration that affects the plastic deformation of α-Fe and the effect of hydrogen concentration on the dislocation slip systems and vacancies,which provides insight into the study of hydrogen-induced microscopic defects in metals.