About this Abstract |
| Meeting |
Materials in Nuclear Energy Systems (MiNES) 2025
|
| Symposium
|
Materials in Nuclear Energy Systems (MiNES) 2025
|
| Presentation Title |
The Effect of Fe3+/He+ Ion Beam Irradiations on Local Deformation Behavior in Tempered Martensitic Steels |
| Author(s) |
Sumin Lee, Diancheng Geng, Minha Park, Yasuyuki Ogino, Hao Yu, Sosuke Kondo, Ryuta Kasada |
| On-Site Speaker (Planned) |
Sumin Lee |
| Abstract Scope |
Tempered martensitic steels (TMS) have been developed as candidate of cladding/structural materials for fast reactors and fusion reactors due to their excellent material properties and irradiation resistance. However, irradiation-induced embrittlement followed by loss-of-elongation in TMS is a critical issue for their long-term usage. In our preceding study [Sumin Lee et al., to be submitted], it was demonstrated that the lath-martensite structure in TMS steels, such as F82H and ARAA reduced activation ferritic steels for fusion reactor structural material, exerts a considerable impact on their local deformation heterogeneity at sub-micron to micron scale even after low-dose proton irradiation up to 0.2 dpa. This is associated with the loss-of-elongation in TMS steels. Here, the present study investigates the effects of higher displacement damage up to 20 dpa and co-implantation of He+ ion on the local deformation behavior of F82H TMS. Nanoindentation testing was conducted to investigate the mechanisms underlying localized deformation before and after irradiations. The deformed microstructure of TMS after nanoindentation was observed by electron back scattering diffraction (EBSD) and scanning transmission electron microscopy (STEM). EBSD analysis revealed slip bands and pile-up features aligned along the prior martensitic lath structures surrounding indentation imprints. STEM observations confirmed formations of irradiation induced defects acting as barriers to dislocation motion and then localized deformation at slip bands. This study offers critical insight of loss-of-elongation phenomenon at macroscale tensile deformation through quantitative evaluation of microscale deformation behavior under nanoindentation. |
| Proceedings Inclusion? |
Undecided |