Correlation between the oxide impedance and corrosion behavior of Zr−Nb−Sn−Fe−Cu alloys

• Published in: Metals and materials international Vol. 10; no. 6; pp. 541 - 548
• Main Authors: Park, Sang-Yoon, Lee, Myung-Ho, Jeong, Yong-Hwan, Jung, Youn-Ho
• Format: Journal Article
• Language: English
• Published: Seoul Springer Nature B.V 01.12.2004; 대한금속·재료학회
• Subjects: Alloys; Aqueous solutions; Copper; Copper base alloys; Correlation; Corrosion; Corrosion resistance; Corrosion tests; Equivalent circuits; Impedance; Iron; Niobium; Oxides; Room temperature; Sulfuric acid; Tin; Zirconium; Zirconium base alloys; 재료공학
• ISSN: 1598-9623; 2005-4149; 1234-4320
• DOI: 10.1007/BF03027416

The correlation between the oxide impedance and corrosion behavior of two series of Zr−Nb−Sn−Fe−Cu alloys was evaluated. Corrosion tests were performed in a 70 ppm LiOH aqueous solution at 360°C for 300 days. The results of the corrosion tests revealed that the corrosion behavior of the alloys depended on the Nb and Sn content. The impedance characteristics for the pre- and post-transition oxide layers formed on the surface of the alloys were investigated in sulfuric acid at room temperature. From the results, a pertinent equivalent circuit model was preferably established, explaining the properties of double oxide layers. The impedance of the oxide layers correlated with the corrosion behavior; better corrosion resistance always showed higher electric resistance for the inner layers. It is thus concluded that a pertinent equivalent circuit model would be useful for evaluating the long-term corrosion behavior of Zr−Nb−Sn−Fe−Cu alloys.