**5. Conclusions**

After ion irradiation of 316L austenitic steel, the LMC behavior was studied for self-ion irradiations, followed by the corrosion tests in LBE with different oxygen concentrations. The 316L specimens were irradiated by 10.5 MeV-Fe3+ ions at a temperature of 450 ◦C, up to 8 dpa at the surface. After conducting the corrosion test at 450 ◦C in LBE with low oxygen concentration, a surface of the nonirradiated area was not oxidized, but corrosive morphology appeared, whereas an iron/chromium oxide layer covered the irradiated area. In the case of a high oxygen concentration in LBE, the surface of the nonirradiated area was oxidized to an iron oxide layer, whereas the irradiated area was covered by the duplex layers of iron and iron/chromium oxides. It is suggested that irradiation can advance the oxide layer formation because of the enhancement of Fe and/or oxygen diffusion induced by the radiation defects in the 316L steel.

**Author Contributions:** Conceptualization, N.O.; SEM observation, Y.F. and M.T.; formal analysis, N.O.; investigation, N.O.; writing—original draft preparation, N.O. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research received no external funding.

**Acknowledgments:** These ion irradiation experiments were performed under the Shared Use Program of QST Facilities. The authors are grateful to S. Ukai for useful comments.

**Conflicts of Interest:** The authors declare no conflict of interest.
