The effect of chromium-based coatings on corrosion behavior of alloy Zr1Nb in 70ppm Li+ water environment

Recent research indicates that one of the leading candidates for Accident Tolerant Fuels (ATF) are chromium-based coatings deposited on the commercially used zirconium alloys. The chromium-based coatings seem to improve the corrosion kinetics of underlying zirconium in both primary water and steam, where zirconium fails to meet the safety requirements. It is well known that the corrosion kinetics of zirconium can be negatively influenced by high concentrations of lithium ions. To evaluate the effect of chromium-based coatings on corrosion behavior of zirconium alloys in water containing elevated concentrations of lithium, Cr and CrN/Cr multilayer coated Zr1Nb alloy was tested in high temperature water containing 70 mg/l Li+. Using Electrochemical Impedance Spectroscopy (EIS), Scanning Electron Microscopy (SEM) and Energy-dispersive X-ray Spectroscopy (EDX), we have found that the chromium coating could have a positive effect on the underlying material as it behaves as a good diffusion barrier for oxygen and Li+ ions. On the other hand, CrN/Cr coating, due to not sufficient structural integrity of the multilayer, showed non-protective behavior to the Zr1Nb alloy. Our results suggest that certain chromium coatings can significantly enhance corrosion resistance in lithium containing water environments.

NOVAK Michal;  NOVOTNY Radek;  VALTR Jaromir;  DASEK David;  CVRČEK Ladislav;  KREJČÍ Jakub;  VRTÍLKOVÁ Vera;  MACAK Jan; 

2024-12-12

ELSEVIER

JRC136839

0022-3115 (online),   

https://www.sciencedirect.com/science/article/pii/S0022311524003477?via%3Dihub,    https://publications.jrc.ec.europa.eu/repository/handle/JRC136839,   

10.1016/j.jnucmat.2024.155245 (online),