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High-Temperature Oxidation Behavior of Fe–10Cr Steel under Different Atmospheres

Authors :
Lei Cheng
Bin Sun
Chongyang Du
Wei Gao
Guangming Cao
Source :
Materials, Vol 14, Iss 13, p 3453 (2021)
Publication Year :
2021
Publisher :
MDPI AG, 2021.

Abstract

Using a thermogravimetric analyzer (TGA), Fe–10Cr steel was oxidized in dry air and in a mixed atmosphere of air and water vapor at a relative humidity of 50% and a temperature of 800–1200 °C for 1 h. The oxidation weight gain curves under the two atmospheres were drawn, the oxidation activation energy was calculated, and the phase and cross-sectional morphology of the iron oxide scales were analyzed and observed by X-ray diffractometry (XRD) and optical microscopy (OM). The results showed that when the oxidation temperature was 800 °C, the spheroidization of Fe–10Cr steel occurred, and the oxidation kinetics conformed to the linear law. At 900–1200 °C, the oxidation kinetics followed a linear law in the preliminary stage and a parabolic law in the middle and late stages. In an air atmosphere, when the oxidation temperature reached 1200 °C, Cr2O3 in the inner oxide layer was partially ruptured. In an atmosphere with a water vapor content of 50%, Cr2O3 at the interface reacted with H2O to generate volatile CrO2(OH)2, resulting in a large consumption of Cr at the interface. At the same time, a large number of voids and microcracks appeared in the iron oxide layer, which accelerated the entry of water molecules into the substrate, as well as the oxidation of Fe–10Cr steel, and caused the iron oxide scales to fall off. Due to the volatilization of Cr2O3 and the conversion from internal oxidation to external oxidation, the internal oxidation zone (IOZ) of Fe–10Cr steel under water vapor atmosphere decreased or even disappeared.

Details

Language :
English
ISSN :
19961944
Volume :
14
Issue :
13
Database :
Directory of Open Access Journals
Journal :
Materials
Publication Type :
Academic Journal
Accession number :
edsdoj.31cad91fc0bd47c299e7b258a22d7a08
Document Type :
article
Full Text :
https://doi.org/10.3390/ma14133453