Microstructural Characteristics of Oxide Films Grown on Zr–0.7Sn–1Nb–0.03Fe–0.2Ge Alloy Corroded in Lithiated Water at 360 °C
The corrosion resistance of a Zr–0.7Sn–1Nb–0.03Fe–0.2Ge (wt%) alloy was investigated by autoclave test in lithiated water with 0.01 M LiOH at 360 °C under a pressure of 18.6 MPa. The microstructure of the oxide film which formed was examined by TEM and SEM. The results revealed that there were a few micro-cracks and more ZrO2 columnar grains in the oxide film formed after exposure for 190 days. The oxidation of second-phase particles (SPPs) was slower than that of α-Zr matrix. The c-ZrO2 was observed around the [Zr–Nb–Fe–Cr–Ge]O SPPs. The amorphous phase produced around the [Zr–Nb–Fe–Cr–Ge]O SPPs could relax the stress in the oxide film. The addition of Ge can reduce micro-pores and micro-cracks formed in oxide film, and delay the microstructural evolution from columnar grains to equiaxed grains. Therefore, the addition of Ge can improve the corrosion resistance of the Zr–0.7Sn–1Nb–0.03Fe alloy.
KeywordsZirconium alloy Germanium Corrosion resistance Oxide film Microstructure
The authors would like to thank Mr. Weijun Yu, Mr. Yuliang Chu, Mr. Xue Liang and Dr. Pengfei Hu for their helping in the microstructure analysis. This study is partly supported by National Natural Science Foundation of China (No. 51171102) and National Advanced Pressurized Water Reactor Project of China (No. 2011ZX06004-023).
- 2.B. X. Zhou, Q. Li, M. Y. Yao, et al., in Zirconium in the Nuclear Industry: Fifteenth International Symposium (ASTM STP 1505, 2009), p. 360.Google Scholar
- 7.B. X. Zhou, W. J. Zhao, et al., China Nuclear Science and Technology Report, CNIC-01074, SINRE-0066 (China Nuclear Information Center, Atomic Energy Press, 1996) (in Chinese).Google Scholar
- 8.H. Anada, B. J. Herb, K. Nomoto, S. Hagi, R. A. Graham, T. Kuroda, in Zirconium in the Nuclear Industry: Eleventh International Symposium (ASTM STP 1295, 1996), p. 74.Google Scholar
- 10.B. Wadman, Z. Lai, et al., in Zirconium in the Nuclear Industry: Tenth International Symposium (ASTM STP 1245, 1994), p. 579.Google Scholar
- 14.S. L. Li, M. Y. Yao, X. Zhang, J. Q. Geng, J. C. Peng and B. X. Zhou, Acta. Metall. Sin. 47, 2011 (163). (in Chinese).Google Scholar
- 15.W. P. Zhang, M. Y. Yao, L. Zhu, J. L. Zhang, B. X. Zhou and Q. Li, Corros. Prot. 34, 2013 (463). (in Chinese).Google Scholar
- 16.M. Y. Yao, L. H. Zou, X. F. Xie, J. L. Zhang, J. C. Peng and B. X. Zhou, Acta. Metall. Sin. 48, 2012 (1097). (in Chinese).Google Scholar
- 19.X. F. Xie, J. L. Zhang, L. Zhu, M. Y. Yao, B. X. Zhou and J. C. Peng, Acta Metall. Sin. 48, 2012 (1487). (in Chinese).Google Scholar
- 20.J. L. Zhang, X. F. Xie, M. Y. Yao, B. X. Zhou, J. C. Peng and X. Liang, Acta Metall. Sin. 49, 2013 (443). (in Chinese).Google Scholar
- 23.B. X. Zhou, Q. Li, W. Q. Liu, et al., Rare Met. Mater. Eng. 35, (7), 2006 (1009). (in Chinese).Google Scholar