About this Abstract |
| Meeting |
2026 TMS Annual Meeting & Exhibition
|
| Symposium
|
Steels in Extreme Conditions
|
| Presentation Title |
Hydrogen-Assisted Twinning Dislocation Reactions in Austenitic Steels |
| Author(s) |
Fernando Daniel León Cázares, Chris San Marchi |
| On-Site Speaker (Planned) |
Fernando Daniel León Cázares |
| Abstract Scope |
Solute hydrogen is known to promote twinning in face-centered cubic metals, including austenitic steels. This behavior, predominantly attributed to a reduction in stacking fault energy, has important implications to material integrity as twins are often linked to damage during hydrogen embrittlement. The current study leverages atomistic simulations and continuum modeling to reveal a novel segregation-assisted dislocation reaction, whereby a 60° dislocation dissociates into a stair-rod dislocation and a Shockley partial that is emitted on a conjugate plane. This is achieved by nucleating a nano-sized hydride at the core of the dislocation, which exerts a force driving the subsequent dissociation as a way to locally increase the tensile hydrostatic stress. In the bulk, this dislocation reaction promotes the formation of extended stacking faults; when on a twin boundary, this mechanism facilitates twin thickening. The results of this work provide new understanding behind the reported increased twinning activity in hydrogen environments. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Iron and Steel, Computational Materials Science & Engineering, Modeling and Simulation |