Abstract
The high-temperature oxidation behavior of coarse-grained (CG) and ultrafine-grained (UFG) 9 %Cr ferritic-martensitic steel in air at 923 K up to 500 h was investigated. The UFG sample showed considerably greater oxidation resistance than the CG sample due to the fact that the outward diffusion of Mn was enhanced and the formation of Mn-rich oxide favored in the former. A duplex-layered scale structure consisting of an outer Fe-rich (Fe, Cr)2O3 layer and an inner Cr-rich (Fe, Cr)2O3 layer was identified on the CG sample, while a thin compact scale with a mixture of (Fe, Cr)2O3, MnCr2O4 and Mn2O3 oxides developed on the UFG sample. A continuous and stable scale composed of Cr-rich (Fe, Cr)2O3 and MnCr2O4 on the UFG sample in the early stage served as a protective barrier between the matrix and environment. With increased oxidation time, formation of Mn2O3 with low growth rate improved the compactness of oxide scale.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
