Research progress on zirconium alloys: applications, development trend, and degradation mechanism in nuclear environment

Abstract In this paper, the research progress of zirconium (Zr) alloys is critically reviewed from the aspects of application, development status, and degradation mechanism in a nuclear environment. The review focused on the application of Zr alloys in the nuclear industry, which are widely used due to their low thermal neutron absorption, good corrosion resistance, and excellent mechanical properties. However, with the increasing requirements in the chemical and medical fields, the application of Zr alloys in these non-nuclear fields is growing due to their excellent properties like good corrosion resistance and low thermal expansion coefficient, as summarized in this review. Additionally, the degradation mechanisms of Zr alloy exposed to a corrosive environment, i.e., corrosion and hydrogen uptake, and the role of alloying selection in minimizing these two phenomena is considered in this review, based on pretransition kinetics and the loss of oxide protectiveness at transition. This is corroborated by the discussion on alloying elements with beneficial and detrimental effects on the corrosion performance of Zr alloys, as well as elements with contradicting effects on Zr alloys corrosion performance owing to the discrepancies in literature. Overall, this review can be leveraged in future alloy design to further improve Zr alloys corrosion resistance in nuclear applications, thus ultimately improving their integrity.