1 State Key Laboratory of Advanced Metallurgy, University of Science and Technology Beijing, Beijing 100083, China 2 School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China 3 Collaborative Innovation Center of Steel Technology, University of Science and Technology Beijing, Beijing 100083, China
Oxidation resistance, thermal expansion and area specific resistance of Fe-Cr alloy interconnector for solid oxide fuel cell
1 State Key Laboratory of Advanced Metallurgy, University of Science and Technology Beijing, Beijing 100083, China 2 School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China 3 Collaborative Innovation Center of Steel Technology, University of Science and Technology Beijing, Beijing 100083, China
ժҪ It is promising for metal especially ferritic stainless steel (FSS) to be used as interconnector when the solid oxide fuel cell (SOFC) is operated at temperature lower than 800 ��C. However, there are many challenges for FSS such as anti-oxidant, poisoning to cathode and high area specific resistance (ASR) when using as SOFC interconnector. The effect of Cr content (12-30 mass%) in Fe-Cr alloys on thermal expansion coefficient (TEC), oxidation resistance, microstructure of oxidation scale and ASR was investigated by thermo-gravimetry, scanning electron microscopy, energy dispersive spectroscopy and four-probe DC technique. The TEC of Fe-Cr alloys is (11-13)��10-6 K-1, which excellently matches with other SOFC components. Alloys have excellent oxidation resistance when Cr content exceeds 22 mass% because of the formation of chromium on the surface of alloy. The oxidation rate constants kd and ks decrease rapidly with increasing the Cr content and then increase slowly when the Cr content is higher than 22 mass%. The kinetic results indicate that Cr evaporation must be considered at high temperature for Fe-Cr alloys. After the alloys were oxidized in air at 800��C for 500 h, log(ASR/T) (T is the absolute temperature) presents linear relationship with 1/T and the conduct activation energy is 0.6-0.8 eV (Cr16-30). Optimal Cr content is 22-26 mass% considering the oxidation resistance and ASR.
Abstract��It is promising for metal especially ferritic stainless steel (FSS) to be used as interconnector when the solid oxide fuel cell (SOFC) is operated at temperature lower than 800 ��C. However, there are many challenges for FSS such as anti-oxidant, poisoning to cathode and high area specific resistance (ASR) when using as SOFC interconnector. The effect of Cr content (12-30 mass%) in Fe-Cr alloys on thermal expansion coefficient (TEC), oxidation resistance, microstructure of oxidation scale and ASR was investigated by thermo-gravimetry, scanning electron microscopy, energy dispersive spectroscopy and four-probe DC technique. The TEC of Fe-Cr alloys is (11-13)��10-6 K-1, which excellently matches with other SOFC components. Alloys have excellent oxidation resistance when Cr content exceeds 22 mass% because of the formation of chromium on the surface of alloy. The oxidation rate constants kd and ks decrease rapidly with increasing the Cr content and then increase slowly when the Cr content is higher than 22 mass%. The kinetic results indicate that Cr evaporation must be considered at high temperature for Fe-Cr alloys. After the alloys were oxidized in air at 800��C for 500 h, log(ASR/T) (T is the absolute temperature) presents linear relationship with 1/T and the conduct activation energy is 0.6-0.8 eV (Cr16-30). Optimal Cr content is 22-26 mass% considering the oxidation resistance and ASR.
��������:Ministry of Science and Technology of China
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E-mail: lijunwang@ustb.edu.cn
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Liu-zhen Bian,Zhi-yuan Chen,,Li-jun Wang,*,Fu-shen Li,Kuo-chih Chou. Oxidation resistance, thermal expansion and area specific resistance of Fe-Cr alloy interconnector for solid oxide fuel cell[J]. �й������ڿ���, 2017, 24(1): 77-83.
Liu-zhen Bian,Zhi-yuan Chen,,Li-jun Wang,*,Fu-shen Li,Kuo-chih Chou. Oxidation resistance, thermal expansion and area specific resistance of Fe-Cr alloy interconnector for solid oxide fuel cell. Chinese Journal of Iron and Steel, 2017, 24(1): 77-83.
2017, Vol. 24 
