| About this Abstract |
| Meeting |
2024 TMS Annual Meeting & Exhibition
|
| Symposium
|
Phase Stability in Extreme Environments II
|
| Presentation Title |
Effect of Hydrogen on the Phase Stability of Steels |
| Author(s) |
Tilmann Hickel, Ali Tehranchi, Joerg Neugebauer |
| On-Site Speaker (Planned) |
Tilmann Hickel |
| Abstract Scope |
In this work, we studied the role of extreme hydrogen concentrations on the relative stability of the fcc/bcc/hcp phases using the ab initio thermodynamics. The results indicate that at low hydrogen chemical potentials the stability of the fcc phase, which can be representative of retained austenite (RA) in steels, is slightly enhanced by the presence of H atoms. In contrast, at high hydrogen chemical potentials the bcc phase is stabilized by H. Moreover, since the excess volume of the hydrogen-rich bcc phase is significantly larger than that of the fcc phase, the presence of a stress field can change the relative stability of these phases in the coexistence regions of the phase diagram. This feature is particularly important for cyclic loading conditions: during loading cycles forward and reverse phase transformations occur and the H released by these transformations can damage the material. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Environmental Effects, Iron and Steel, Phase Transformations |