[1A01-06] Liquid Metal and Functional Materials

[1A01] Formation behavior and adhesion strength of protective oxide layer on FeCrAl-ODS alloys

*Yoshiki Kitamura¹, Naoko Oono², Yoshimitsu Hishinuma³, Masatoshi Kondo¹ (1. Tokyo Tech, 2. Yokohama Natl. Univ., 3. NIFS)

Keywords:Oxide layer, FeCrAl alloy, Micro-scratch test, Adhesion strength

The chemical compatibility of structural materials with liquid metals is one of the critical issues for the development of liquid metal-based energy power plants. FeCrAl alloys revealed excellent corrosion resistance because of the formation of a protective α-Al₂O₃ layer by pre-oxidation treatment. The treatment condition should be optimized since layer properties depend on the temperature and the duration. In the present study, FeCrAl alloys were pre-oxidized at 1273K and 1373K. The adhesion strengths and the microstructure of α-Al₂O₃ layers were investigated by micro-scratch test and STEM/EDS analysis. The enrichment of the reactive elements (Ti, Y, Zr) contained in ODS alloys was recognized along the grain boundaries of α-Al₂O₃ layers and contributed to their growth as a diffusion path of oxygen.