About this Abstract |
| Meeting |
2026 TMS Annual Meeting & Exhibition
|
| Symposium
|
Interrelated Extremes in Materials Degradation for Fission and Fusion Environments
|
| Presentation Title |
Dislocation effects on high temperature He embrittlement in iron-based alloys |
| Author(s) |
Zehui Qi, Miguel L. Crespillo, Steven John Zinkle |
| On-Site Speaker (Planned) |
Zehui Qi |
| Abstract Scope |
For fusion reactor and Gen IV reactor concepts, the higher operating temperatures and radiation doses represent new materials challenges. High-temperature helium embrittlement (HTHE) may be one mechanism that limits the lifetime of potential structural materials. Previous in-situ creep tests have shown that tensile stress can significantly enhance HTHE. However, our observations suggest that elastic stress alone, without a threshold dislocation density, does not induce noticeable stress-enhanced HTHE effects. In this study, 316L stainless steel and Fe-9%Cr alloys with varying pre-existing dislocation densities were helium-implanted to a peak concentration of ~1800 appm, both with and without an initial elastic stress of ~100 MPa at 750 °C. The size and number density of cavities (both in the matrix and at grain boundaries) were characterized by TEM to investigate cavity behavior in relation to applied stress and dislocation density. The results indicate that plastic deformation (dislocations) plays an important role in HTHE. |
| Proceedings Inclusion? |
Planned: |