Observation of hydrogen diffusion channel and hydrogen trap in 304 austenitic stainless steel

Abstract Hydrogen embrittlement (HE) involves hydrogen-defect interactions at multiple-length scales. However, the challenge of measuring the precise location of hydrogen atoms limits our understanding. We used time of flight-secondary ion mass spectrometer (TOF-SIMS) to observe hydrogen localization in 304 austenitic stainless steel. A large amount of hydrogen observed at grain boundary in cold-rolled steel contains strain-induced α′-martensite provides direct evidence that α′-martensite act as hydrogen diffusion channel and grain boundaries act as trapping sites, which achieves a mechanistic understanding of hydrogen materials interactions and facilitates the development of hydrogen-resistant steels.