Hydrogen effects on the migration of nanoscale cavities in iron

Abstract

Accurate knowledge of the influence of hydrogen on the behavior of vacancies and vacancy clusters is crucial for understanding the mechanism of hydrogen embrittlement of α-iron and its alloys. Using in-situ transmission electron microscopy, we examined the effects of hydrogen on the behavior of nanoscale cavities under heating, by comparison between the behaviors of cavities without hydrogen produced upon high-energy electron irradiation and those with hydrogen produced upon electro-deposition. It is revealed that hydrogen promotes the migration of cavities, in contrast to a traditional notion.