Mugilgeethan Vijendran (Mugilgeethan Vijendrana Department of Mechanical and Electrical Systems Engineering,, Kyoto University) ; Ryosuke Matsumoto (Department of Mechanical and Electrical Systems Engineering, Kyoto University)
Collection
Citation
Description:
(abstract)This study proposes a novel mechanism of intergranular fracture in alpha-iron, focusing on the effects of trapped vacancies, H atoms, and their synergistic interplay under tensile strain. We present a methodology for the introduction of H into grain boundaries (GBs) resulting in a realistic distribution by considering H – H interactions. Accordingly, optimal H concentrations were determined under specific environmental conditions for GBs with and without vacancy-induced segregation under zero and 2% tensile strain, respectively. Subsequently, the reduction in cohesive energy at GBs was evaluated at the optimal H concentration under these conditions. In the case of H segregation without vacancies at zero applied strain, the reduction in the cohesive energy ranged approximately from 15% to 35% for all the GB configurations. Eventually, vacancy segregation increased H concentration at the GBs, defined as vacancy-induced H segregation. The vacancy-induced H segregation resulted in a 60%–117% increase in H concentration and a 70%–80% decrease in cohesive energy at a vacancy concentration of 7.491/nm2 under zero applied strain. The proposed vacancy-induced H-segregation mechanism explained the delayed fracture in steel. Furthermore, the effect of tensile strain on embrittlement was elucidated, with strain-induced vacancy redistribution and vacancy-induced H segregation synergistically promoting GB decohesion, resulting in a 73%–93% reduction in cohesive energy at the same vacancy concentration.
Rights:
Keyword: Intergranular failure, Iron, Tensile behavior, Hydrogen, Vacancy-induced
Date published: 2025-12-31
Publisher: Taylor & Francis
Journal:
- Science and Techonology of Advanced Materials (ISSN: 14686996) vol. 26 2459060
Funding:
Manuscript type: Author's version (Accepted manuscript)
MDR DOI: https://doi.org/10.48505/nims.5322
First published URL: https://doi.org/10.1080/14686996.2025.2459060
Related item:
Other identifier(s):
Contact agent:
Updated at: 2025-02-13 12:30:17 +0900
Published on MDR: 2025-02-13 12:30:18 +0900
| Filename | Size | |||
|---|---|---|---|---|
| Filename |
Interplay between vacancy-induced hydrogen segregation and stress-induced vacancy redistribution causing embrittlement of alpha-iron.pdf
(Thumbnail)
application/pdf |
Size | 6.35 MB | Detail |