Hydrogen effects on deformation-induced γ-ε martensitic transformation were revisited in terms of morphology, number density, and fraction of ε-martensite in strained austenitic steel. Hydrogen charging suppresses the stress-assisted nucleation of the martensite in stress criterion, which is consistent with a previous finding that hydrogen suppresses thermally induced γ-ε martensitic transformation. At an identical strain (e.g., 4%), hydrogen charging decreases the average thickness of ε-martensite plates, but increases their number density. As a result, hydrogen charging promotes deformation-induced γ-ε martensitic transformation when compared at the identical strain. These facts provide the following two conclusions: (1) hydrogen increases the required elastic strain energy for martensite nucleation and (2) hydrogen promotes a dislocation-motion-related nucleation process.
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering