| About this Abstract |
| Meeting |
2025 TMS Annual Meeting & Exhibition
|
| Symposium
|
Environmentally Assisted Cracking: Theory and Practice
|
| Presentation Title |
Sub-Stoichiometry and Vacancy Structures in Carbide Precipitates in Steels, and Implications to Hydrogen Embrittlement |
| Author(s) |
Jun Song, Xiaohan Bie |
| On-Site Speaker (Planned) |
Jun Song |
| Abstract Scope |
Employing a cluster expansion approach combined with first-principles calculations, we investigated the sub-stoichiometry induced by C vacancies within V/Nb carbides. Ground-state sub-stoichiometric V/Nb carbide compounds as the C composition varies were predicted, consistent with experimental observations, also supported by the good agreement with experimental measurements. It was demonstrated that C vacancies in the carbides would arrange into particular patterns, with notable preference to specific vacancy pairs and triplets. Such vacancy pattern formation was elucidated to be mainly driven by the elastic interaction between vacancies. The interaction between hydrogen and these vacancy patterns was then examined, showing that the sub-stoichiometry has critical implications to trapping and diffusion of hydrogen in carbides. The findings are critical for accurate understanding of the structures and properties of carbides and their role in hydrogen embrittlement in steels, offer essential inputs for engineering steels of enhanced performance. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Environmental Effects, Modeling and Simulation, Other |