On the fate of hydrogen during zirconium oxidation by water: effect of oxygen dissolution in α-Zr
Abstract
Zirconium oxidation by water is accompanied by hydrogen conversion, either H2 is released or hydrogen is picked up by the alloy. Strategies are sought to mitigate the detrimental hydrogen uptake into the metal. The corrosion phenomenon is subdivided into anode and cathode processes caused by electron release upon O2− oxidation at the metal/oxide interface in the case of the former and electron–proton recombination resulting in hydrogen pick-up or H2 evolution in the case of the latter. In a previous study, the additive dependence of the cathodic hydrogen evolution reaction was analysed. The present study examines the oxygen concentration dependence of the anode potential, presents the impact of oxygen concentration on the co-absorption of hydrogen and merges the anode and cathode processes. The computational model is validated by semi-quantitatively reproducing the experimental solubility limit for oxygen in α-Zr. The impact of the emerging conceptual understanding for material development is discussed.