Mechanisms Investigation Of Cathodic-Anodic Coupling Reaction Of Zr-H2o At 360 Degrees C By Long-Term In-Situ Electrochemical Polarization Analyses

Long-term on-line monitoring of in-situ electrochemical polarization curves were conducted on two zirconium claddings during corrosion in 360 degrees C water. Results suggest that cathodic reaction is activation-controlled, while anodic reaction is diffusion-controlled. Cathodic Tafel constants match well with the value predicted by Tafel kinetics and different hydrogen evolution reaction mechanisms of alloys with corrosion time are observed. Generally, recombination of hydrogen atoms becomes harder with time and is even harder in one of the alloys, which is proposed to increase the diffusion probability of hydrogen atoms into zirconium matrix. This proposal is in good agreement with experimental data.