Steam oxidation of Cr-coated Sn-containing Zircaloy solid rod at 1000 °C. (September 2021)

• Record Type: Journal Article
• Authors: Liu, Junkai; Cui, Zhexin; Hao, Zhe; Ma, Dayan; Lu, Junqiang; Cui, Yanguang; Li, Chong; Liu, Wenbo; Xie, Shijing; Hu, Pengfei; Huang, Ping; Bai, Guanghai; Yun, Di
• Is Part Of: Corrosion science. Volume 190(2021)
• Publication Date: 2021-09
• Subjects: Cr coating -- High-temperature steam oxidation -- Precipitate -- Interface void -- Amorphous structures; Corrosion and anti-corrosives -- Periodicals; 620.11223
• DOI: 10.1016/j.corsci.2021.109682
• Languages: English
• ISSNs: 0010-938X

Abstract

Highlights: Sn precipitated in Cr2 O3 layer after steam oxidation of Cr-coated Zry-4 at 1000 ℃. The outward diffusion and selective oxidation of Zr in Cr layer were studied. Larger outward mass flow caused in Kirkendall cavities close to Zr/ZrCr2 interface. Voids formed at oxide/metal interface of coating due to vacancy condensation. Amorphization of Cr2 O3 was observed which due to the decomposition of Cr2 O3 grains. Abstract: In this study, the steam oxidation behavior of Cr-coated Zry-4 alloy at 1000 °C and the various interesting phenomena observed during the oxidation process were investigated. During oxidation, Sn in the Zry-4 substrate diffused into the coating and precipitated in the Cr2 O3 scale. The Kirkendall effect of these Sn-containing precipitates then generated microcavities. Furthermore, the outward diffusion behavior of Zr and the selective oxidation mechanism of the Zr particles were studied. Voids detected at the Cr2 O3 /Cr interface result mainly from vacancy condensation. The amorphization of Cr2 O3 was also observed adjacent to the voids, and the amorphization mechanism was discussed.