About this Abstract |
| Meeting |
2026 TMS Annual Meeting & Exhibition
|
| Symposium
|
Accelerated Qualification Methods for Nuclear Reactor Structural Materials
|
| Presentation Title |
Understanding the Effect of Nitrogen on Cavity Formation and Precipitate Stability Using Correlative STEM-APT Technique |
| Author(s) |
Xingyu Liu, Xing Wang |
| On-Site Speaker (Planned) |
Xingyu Liu |
| Abstract Scope |
Ferritic-martensitic (FM) steels are promising structural materials for advanced nuclear reactors. Previous studies have shown that nitrogen addition in HT9 FM steel can significantly improve swelling resistance and suppress G-phase growth in the alloy. Characterizing nitrogen distribution may shed light upon the mechanisms behind these phenomena. However, such characterization is challenging due to the small sizes of nitrogen clusters or nitrides, limitations of two-dimensional projection in scanning transmission electron microscope (STEM), and peak overlap between 14N+ and 28Si2+ in atom probe tomography (APT) spectrum. To investigate the nitrogen impact on cavity formation, G-phase formation, and MX precipitate stability, HT9 was first implanted with 2MeV 15N isotope and then irradiated with 9MeV Fe and 3.42MeV energy-degraded He ions. By using correlative STEM-APT, significant nitrogen segregation was found in G-phase precipitates, dislocations, and grain boundaries. No nitrogen segregation was observed near cavities. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Nuclear Materials, Characterization, Iron and Steel |