Characterization of high-temperature oxide films on dysprosium-doped Fe-20Cr alloys by electrochemical techniques
来源期刊：Journal of Rare Earths2012年第11期
论文作者：郭平义 曾潮流 邵勇 秦泽尚
文章页码：1150 - 1157
摘 要：The oxidation properties of Fe-20Cr,Fe-20Cr-0.2Dy and Fe-20Cr-1Dy alloys were studied using gravimetric and electrochemical techniques.The high-temperature oxide films of Dy-doped Fe-20Cr alloys were prepared in air at 900 oC for 24,48 and 100 h,respectively.The electrochemical experiment was performed by a three-electrode electrochemical cell and in 0.1 mol/L Na2SO4 aqueous solution.Proper models were built for describing electrochemical impedance spectroscopy of the different oxide layers and the spectra were interpreted in terms of a two-layer model of the films.The results revealed that the oxide films of Dy-doped Fe-20Cr alloys became compacter than that of undoped alloys and retained their good protective ability for a relatively long time.With increasing content of Dy,the protection of the oxide films slightly decreased.Mott-Schottky curves indicated that all the oxides were n-type semi-conductors,and the Nd value of oxide film on Fe-20Cr was much larger than that of Dy-doped Fe-20Cr alloys.The results of kinetic curves and SEM were in agreement with electro-chemical impedance spectroscopy and Mott-Schottky data.
郭平义1,2，曾潮流3，邵勇2，秦泽尚2
1. State Key Laboratory for Corrosion and Protection,Institute of Metal Research,Chinese Academy of Sciences,Shenyang 1100162. Jiangsu Provincial Key Laboratory of Advanced Welding Technology,Jiangsu University of Science and Technology3. State Key Laboratory for Corrosion and Protection,Institute of Metal Research,Chinese Academy of Sciences
摘 要：The oxidation properties of Fe-20Cr,Fe-20Cr-0.2Dy and Fe-20Cr-1Dy alloys were studied using gravimetric and electrochemical techniques.The high-temperature oxide films of Dy-doped Fe-20Cr alloys were prepared in air at 900 oC for 24,48 and 100 h,respectively.The electrochemical experiment was performed by a three-electrode electrochemical cell and in 0.1 mol/L Na2SO4 aqueous solution.Proper models were built for describing electrochemical impedance spectroscopy of the different oxide layers and the spectra were interpreted in terms of a two-layer model of the films.The results revealed that the oxide films of Dy-doped Fe-20Cr alloys became compacter than that of undoped alloys and retained their good protective ability for a relatively long time.With increasing content of Dy,the protection of the oxide films slightly decreased.Mott-Schottky curves indicated that all the oxides were n-type semi-conductors,and the Nd value of oxide film on Fe-20Cr was much larger than that of Dy-doped Fe-20Cr alloys.The results of kinetic curves and SEM were in agreement with electro-chemical impedance spectroscopy and Mott-Schottky data.
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