Atomistic modeling of oxide-carbide growth on FeCr alloy surface in high-temperature CO2. (1st August 2022)

• Record Type: Journal Article
• Authors: Qi, Jing; Sheng, Ganwen; Liu, Chenhan; Wang, Yuwei; Xu, Hong; Lu, Ping; Peng, Xianyong
• Is Part Of: Corrosion science. Volume 204(2022)
• Publication Date: 2022-08-01
• Subjects: High-temperature CO2 -- FeCr alloy -- Oxidation -- Carbonization -- Molecular dynamics; Corrosion and anti-corrosives -- Periodicals; 620.11223
• DOI: 10.1016/j.corsci.2022.110391
• Languages: English
• ISSNs: 0010-938X

Abstract

Abstract: This study investigates the atomistic mechanism of oxide-carbide growth on FeCr alloy surface. Simulation results demonstrate that Cr atoms segregate outward and form chain-like oxide above the surface initially. Afterward, more C atoms and O atoms penetrate into the alloy, leading to the growth of inner oxide and interior carbide. Meanwhile, driven by the oxidation-induced internal stress, Fe atoms in the inner oxide move outward and form Fe-rich outer oxide. Interestingly, the oxide-carbide growth is strongly affected by the temperature but not sensitive to the CO2 concentration at the initial stage. These results coincide with experimental and DFT study. Highlights: At the initial stage, Cr atoms in the alloy surface segregate outward and form chain-like oxide above the surface initially. C atoms and O atoms penetrate into the alloy, leading to the growth of inner oxide and interior carbide. Driven by the oxidation-induced internal stress, Fe atoms in the inner oxide move outward and form Fe-rich outer oxide. The oxide-carbide growth is strongly affected by the temperature but not sensitive to the CO2 concentration at the initial stage.