Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Kondo, Masatoshi*; Kitamura, Yoshiki*; Kawarai, Atsushi*; Saito, Shigeru; Obayashi, Hironari
Corrosion Science, 262, p.113646_1 - 113646_14, 2026/04
Times Cited Count：0 Percentile：0.00(Materials Science, Multidisciplinary)The corrosion resistance of FeCrAl alloy APMT (Fe-21Cr-5Al-3Mo) in flowing lead-bismuth eutectic (LBE) was investigated by corrosion tests performed at 723 K using a non-isothermal forced convection loop. The oxygen concentration in flowing LBE was controlled at 1
10
wt%. No severe corrosion or erosion was detected on the specimens exposed to flowing LBE for 2000 h and 4000 h. Multiple oxide layers consisting of Fe-rich, Cr-rich and Al-rich sub-layers were formed in situ on the surface of APMT during the corrosion tests, which effectively suppressed corrosion and erosion. The oxide layers were intentionally removed by gentle abrasion prior to re-immersion and the specimens were then re-immersed in flowing LBE for an additional 2000 h. The oxide layers were spontaneously re-formed in situ on the abraded surface. This behavior indicates a self-healing capability. The results of micro-scratch tests indicated that the in-situ formed multiple oxide layers exhibited high adhesion strength in the shear direction after the 2000 h corrosion test.
Kawarai, Atsushi*; Obayashi, Hironari; Saito, Shigeru; Sasa, Toshinobu; Kondo, Masatoshi*
no journal, ,
FeCrAl alloys are promising structural materials for liquid metal blankets of fusion reactor because they form a self-healing alumina film on the surface and exhibit excellent coexistence with liquid metal. The purpose of this study is to clarify the formation and repair behavior of the oxide film in liquid metal. The corrosion tests were performed using the high temperature lead-bismuth flow corrosion test loop (OLLOCHI) for accelerator-driven system research at JAEA. Test conditions were lead-bismuth temperature of 450/350
C and oxygen concentration of 10wt%. The specimens were strips of APMT with and without pre-oxidation. Pre-oxidation treatment formed an alumina film of about 400 nm on the surface of the specimens, and no corrosion was observed after 2,000 hours of corrosion testing. On the other hand, the specimen without pre-oxidation formed an alumina film of about 37 nm on the surface after corrosion testing, and no corrosion was observed. To further evaluate the self-healing behavior of the oxide film, the specimens were artificially damaged by grinding to a width of 2 mm and subjected to 2,000-hour corrosion test. As a result, it was found that an oxide film of about 30 nm thickness was re-formed in the damaged area of the specimen. This is almost the same thickness as the undamaged area, and no corrosion was observed. It was found that APMT steel, with or without pre-oxidation, exhibited excellent coexistence in liquid LBE by self-forming and repairing a highly corrosion-resistant film.
Kitamura, Yoshiki*; Kawarai, Atsushi*; Kondo, Masatoshi*; Saito, Shigeru; Obayashi, Hironari
no journal, ,
FeCrAl alloys are promising structural materials for accelerator driven systems (ADSs) and lead cooled fast reactors (LFRs). The corrosion tests of APMT (Fe-21Cr-5Al-3Mo) were performed in flowing lead bismuth eutectic (LBE) for 2000 
4000 hours at temperature of 450 C, oxygen concentrations of 10-4-10-6 wt.% and flow velocity of 1 m/s by OLLOCHI loop (JAEA/J-PARC). The in-situ self-healing behavior of the oxide layer in flowing LBE was clarified by means of the corrosion test with the specimen in which the protective oxide layer was artificially removed in the middle of the corrosion test. The relationship between the adhesion in the shear direction and the roughness of the layer-substrate interface was also clarified.
