Effect of pre-oxidation on the corrosion behavior of Al-containing ODS steel in oxygen- saturated static LBE at 600 and 700°C

• Published in: Journal of nuclear materials Vol. 600; p. 155298
• Main Authors: Li, Xinle, Bao, Feiyang, Zhang, Jiarong, Wang, Qitao, Li, Yaozhi, Yin, Mengjie, Yan, Wei, Li, Yanfen
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.11.2024
• Subjects: Corrosion; lead-bismuth eutectic (LBE); Oxide dispersion strengthened steel (ODS); Pre-oxidation; lead-bismuth eutectic (LBE); Oxide dispersion strengthened steel (ODS); Corrosion; Pre-oxidation
• ISSN: 0022-3115
• DOI: 10.1016/j.jnucmat.2024.155298

•The effects of pre-oxidation heat treatment on corrosion behavior of Al-containing ODS steel in static liquid Pb-Bi at 600 °C and 700 °C was studied.•Optimized pre-oxidation treatment can effectively improve the corrosion resistance of Al-containing ODS steel at 600 °C by the formation of a protective Al2O3.•Corrosion behavior of Al-containing ODS steel was different when exposed to liquid Pb-Bi at 700 °C compared with that at 600 °C.•Some oxide nodules were emerged in localized surface during exposure at 700 °C for 500 h, which may lead to the decrease in corrosion resistance. The corrosion behavior of an Al-containing oxide dispersion strengthened (ODS) steel at 600 and 700°C oxygen-saturated static Pb-Bi eutectic was investigated with and without a pre-oxidation heat treatment. Without pre-oxidation, the ODS steel formed a multilayer oxide scale consisting of outer Pb-Fe-O/magnetite and inner Fe-Cr-Al spinel/Cr(Al)-rich film on the surface during the corrosion exposure at 600°C up to 3100 h. In contrast, the pre-oxidized ODS samples was covered by a thin, dense and continuous pre-formed Al2O3 scale, which effectively improved the corrosion resistance. Although the Al2O3 scale was gradually reacted with Pb-O clusters to form Pb-Al-O compound with the prolonged exposure time to 3100 h, the total thickness of oxide layers was still less than about 1 μm. Exposed to elevated temperature of 700 °C, the corrosion mode changed significantly. Both ODS samples spontaneously formed an external Al2O3 during the exposure for 100 h. However, with prolonged exposure time to 500 h at 700 °C, the integrity of the protective Al2O3 scale gradually destructed. Small nodule-like oxides emerged from localized areas in the pre-oxidized samples, while more thicker oxide layer was form in the as-received samples. which intensified corrosion by the aggressive LBE melt. The results suggest that optimized pre-oxidation treatment can effectively to improve the corrosion resistance of Al-containing ODS steel.