Influence of Ni content on the oxidation behavior of alumina-forming Co-based oxide dispersion strengthened superalloys at 900 °C. (March 2023)

• Record Type: Journal Article
• Authors: Yu, Hao; Kondo, Sosuke; Kasada, Ryuta; Ukai, Shigeharu
• Is Part Of: Corrosion science. Volume 212(2023)
• Publication Date: 2023-03
• Subjects: Co-based superalloys -- ODS -- Alumina -- TEM; Corrosion and anti-corrosives -- Periodicals; 620.11223
• DOI: 10.1016/j.corsci.2022.110933
• Languages: English
• ISSNs: 0010-938X

Abstract

Abstract: This work systematically investigated the effect of Ni additions of 10, 20 and 30 at% on the oxidation behavior of oxide dispersion-strengthened (ODS) Co-20Cr-15Al (at%) superalloys at 900 °C in air. Alumina scale with a duplex structure consisting of outer θ-alumina and inner α-alumina was formed on all tested Co-based ODS superalloys. Ni addition reduced the oxidation rate by inhibiting the growth of the outer θ-alumina during initial oxidation and the inner α-alumina during prolonged exposure. Cr2 O3 formation between the interface of the θ- and α-alumina layers was confirmed with the increase of Ni content. Highlights: Ni effect on oxidation behavior of alumina-forming Co-based ODS superalloys has been investigated at 900 ºC for 225 h. Ni addition decreased the overall growth rate of the multi-component alumina scales. Ni addition promoted the formation of Cr2 O3 during the initial oxidation stage.