Effects of Si Content on the Oxidation Behavior of Fe–Si Alloys in Air

Abstract:

The oxidation behavior of Fe–Si alloys at 1073K in air was investigated. The oxidation kinetics described by the parabolic rate law of diffusion controlled oxidation and the oxidation rate decrease with the increasing Si content. Fe-Si alloys were oxidized for different times at 1073K to obtain the same scale thickness of approximately 30μm. Observations of scale cross-sections indicated the structure of oxide scale and elemental distribution in oxide scales strongly depends on Si content. The oxide scale on Fe-Si alloys with low Si content consisted of three layers with an outer Fe₂O₃, an intermediate Fe₃O₄ and an inner FeO and some voids were formed in Fe₃O₄ and FeO layers. The Si-rich oxide layer was formed at the scale/alloy interface of Fe-Si alloys with high Si content. Furthermore, the amount of internal oxidation zone increased with the increasing Si content. Observations of scale cross-sections indicated that the structure of oxide scale and elemental distribution in oxide scale strongly depend on Si content.

• Periodical: Materials Science Forum (Volume 696)
• Pages: 126-131
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.696.126
• Online since: September 2011
• Authors: Takumi Nishimoto, Kazuhiko Honda, Yasumitsu Kondo, Kenichi Uemura
• Keywords: Electron Backscatter Diffraction (EBSD), Fe₂O₃, Fe₂SiO₄, Fe₃O₄, FeO, Fe-Si Alloys, High Temperature Oxidation, Scale Structure

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