About this Abstract |
| Meeting |
2026 TMS Annual Meeting & Exhibition
|
| Symposium
|
Environmentally Assisted Cracking: Theory and Practice
|
| Presentation Title |
Imaging the Effect of Hydrogen on Dislocations in Steel With Dark-Field X-Ray Microscopy (DFXM) |
| Author(s) |
Dayeeta Pal, Dorian Luccioni, Can Yildirim, Christopher San-Marchi, Leora Dresselhaus-Marais |
| On-Site Speaker (Planned) |
Dayeeta Pal |
| Abstract Scope |
The fundamental mechanisms of hydrogen (H) embrittlement remain poorly understood. H atoms form a solid solution of interstitial defects in metals, altering dislocation behavior. While dislocations are essential to understand metal plasticity, it is unclear whether H enhances dislocation mobility (Hydrogen Enhanced Localized Plasticity-HELP) or reduces it (Solute Drag Theory-SDT), with no technique being able to image deep subsurface dislocations. DFXM has been developed to study large populations of subsurface dislocations in metals. Our work uses DFXM to generate 3D dislocation maps in uncharged and H-pre-charged single crystal FCC-austenitic stainless steel. We compare how H influences the packing of dislocations into distinct structures and generates a higher geometrically necessary dislocation density. These changes in dislocation features observed in 3D-DFXM microscopy alter lattice rotations and indicate stress hotspots that we predict are conducive to crack initiation in hydrogen-charged samples, providing direct measurements of hydrogen's role in altering dislocations in austenitic steel. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Iron and Steel, Mechanical Properties, Other |