About this Abstract |
| Meeting |
Materials in Nuclear Energy Systems (MiNES) 2025
|
| Symposium
|
Materials in Nuclear Energy Systems (MiNES) 2025
|
| Presentation Title |
Proton Irradiated Microstructure Evolution of δ-Ferrite in an Austenitic Stainless Steel Weld: Effect of Pre-Existed Precipitate |
| Author(s) |
Byeong Seo Kong, Ji Ho Shin, Chaewon Jeong, Changheui Jang |
| On-Site Speaker (Planned) |
Byeong Seo Kong |
| Abstract Scope |
The irradiation-induced microstructure evolution of δ-ferrite in an austenitic stainless steel weld was investigated to understand the degradation mechanism related to irradiation embrittlement. To simulate the long-term service environment of light water reactors (LWRs), accelerated thermal aging was conducted at 400 for up to 30,000 hours. Proton irradiation was then performed on both as-welded and thermally aged specimens up to 1 dpa. In the aged condition, phase decomposition into Cr-rich α′ phase and G-phase precipitation was evident. However, following irradiation, the pre-existing Cr-rich phase was significantly diminished, while G-phase precipitates increased notably. In contrast, the as-welded samples exhibited clear formation of Cr-rich α′ phase through irradiation-induced spinodal decomposition, with relatively limited G-phase development. This discrepancy in microstructural evolution between aged and unaged conditions is attributed to differences in initial microstructure, particularly the presence of pre-existing α′ phases and their lower irradiation stability compared to G-phase. The findings suggest that the initial state of δ-ferrite plays a critical role in determining the irradiation response and long-term embrittlement behavior of stainless steel welds in nuclear reactor environments. Understanding these mechanisms contributes to improved prediction of microstructural stability and mechanical performance under extended service conditions. |
| Proceedings Inclusion? |
Undecided |