Effect of Co addition on the high-temperature oxidation behavior of oxide-dispersion-strengthened FeCrAl alloys. (15th May 2021)

• Record Type: Journal Article
• Authors: Zhang, Shenghua; Hayashi, Shigenari; Ukai, Shigeharu; Oono, Naoko Hori
• Is Part Of: Corrosion science. Volume 184(2021)
• Publication Date: 2021-05-15
• Subjects: FeCrAl-ODS -- Co addition -- Reactive element -- Oxidation behavior; Corrosion and anti-corrosives -- Periodicals; 620.11223
• DOI: 10.1016/j.corsci.2021.109391
• Languages: English
• ISSNs: 0010-938X

Abstract

Highlights: 5 wt.% of Al is sufficient for forming exclusive α-Al2 O3 scales on the surfaces of ferritic and austenitic FeCrAlCo alloys at 1000 °C in air. Co addition decreased the solute Y in oxide dispersion strengthened FeCrAl alloy substrate resulting in the suppression of Y segregation at grain boundaries of Al2 O3 scale. The weakened Y segregation caused Al2 O3 grain size coarsening. Co addition decreased the oxidation kinetics of oxide dispersion strengthened FeCrAl alloy at 1000 °C. Abstract: The effect of Co addition on the high-temperature oxidation behavior of oxide dispersion-strengthened (ODS) FeCrAl alloys was investigated at 1000 °C in air. Exclusively α-Al2 O3 scale formed on the surfaces of alloys containing 5 wt.% Al, and Y segregation was observed at the grain boundaries of Al2 O3 scale. The solute Y in the Fe12Cr5Al-ODS (wt.%) alloy substrate was decreased by Co addition, thus limiting Y segregation at grain boundaries of the Al2 O3 scale. The diminished Y segregation was inferred to cause grain size coarsening, which accounted for the slower oxidation kinetics of 5Al alloys with Co addition.