About this Abstract |
| Meeting |
2026 TMS Annual Meeting & Exhibition
|
| Symposium
|
Environmentally Assisted Cracking: Theory and Practice
|
| Presentation Title |
Grain Boundary–Specific Hydrogen Segregation in Austenitic Alloys Characterized by Cryogenic Atom Probe Tomography |
| Author(s) |
Venkata Bhuvaneswari Vukkum, Semanti Mukhopadhyay, Jack Grimm, Arun Devaraj |
| On-Site Speaker (Planned) |
Arun Devaraj |
| Abstract Scope |
This study advances the mechanistic understanding of grain boundary-mediated hydrogen effects in metallic alloys while establishing an optimized needle preparation and cryogenic transfer protocol for reliable H-quantification using cryogenic focused ion beam (Cryo-FIB) and atom probe tomography (APT). H-segregation at grain boundaries is a critical precursor to hydrogen embrittlement and stress corrosion cracking, yet the influence of specific boundary types on hydrogen trapping remains poorly understood. To address this, we employed APT to quantitatively assess H-distribution in a model austenitic FeCrNi alloy subjected to cathodic electrochemical charging. Cryo-FIB and vacuum-based cryo-transfer were utilized to preserve H-distributions with minimal loss or redistribution. Our analysis reveals distinct segregation behavior at high-angle grain boundaries and Σ3 boundaries, highlighting the microstructure sensitivity of H-trapping. This work demonstrates a robust cryo-APT methodology for investigating hydrogen-assisted degradation and provides critical insight into the role of grain boundary character in influencing hydrogen uptake. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Environmental Effects, Iron and Steel, Characterization |