Density functional theory calculations of iron - vanadium carbide interfaces and the effect of hydrogen

According to recent experimental research, vanadium-carbide precipitates can improve hydrogen resistance and hardness in steels. In the present article, density functional theory calculations are performed to study the structure and energetics of iron–vanadium carbide interfaces and how hydrogen interacts with them. A comparison of the solubility of hydrogen in different sites shows that hydrogen will tend to segregate towards the iron–vanadium carbide interface and that carbon vacancies within a vanadium carbide precipitate behave as strong hydrogen traps. Additionally, it is shown that the presence of hydrogen at an iron–vanadium carbide interface does not cause a significant embrittlement of the material.