About this Abstract |
| Meeting |
Materials in Nuclear Energy Systems (MiNES) 2025
|
| Symposium
|
Materials in Nuclear Energy Systems (MiNES) 2025
|
| Presentation Title |
PM-HIP Processing Delays Irradiation-Induced Cu Clustering and Embrittlement in Grade 91 Ferritic Steel |
| Author(s) |
Soumita Mondal, Arya Chatterjee, Yu Lu, Yaqiao Wu, Janelle Wharry |
| On-Site Speaker (Planned) |
Soumita Mondal |
| Abstract Scope |
In this study we show that powder metallurgy with hot isostatic pressing (PM-HIP) processing can limit irradiation embrittlement associated with Cu-rich precipitates (CRPs) in Grade 91 ferritic steel. Grade 91 steel fabricated via PM-HIP and casting, which have nearly identical bulk compositions, are neutron irradiated at ~360°C to 1 and 3 dpa. Uniaxial tensile tests show the PM-HIP material exhibits extended yielding, while the cast material shows higher embrittlement. Atom probe tomography (APT) reveals that the cast material nucleates significantly more and larger CRPs than the PM-HIP material, enabling Mn-Ni-Si co-precipitation (MNSP) as appendages. CRP formation in the casting is attributed to rapid radiation enhanced diffusion (RED), with CRP-MNSP co-clusters as early as 1 dpa. On the contrary, PM-HIP processing suppresses CRP formation and decouples MNSPs from CRPs. Rapid Si segregation to dislocations in the PM-HIP material delays RED of Cu and depletes availability of Si for formation of MNSPs. The higher dislocation density associated with PM-HIP processing presents a novel route toward suppression of irradiation-induced nanoprecipitation and the extension of yielding and ductility. |
| Proceedings Inclusion? |
Undecided |