Research progress on corrosion and protection of zirconium alloys

Abstract

Zirconium alloys are widely used as structural materials in civil power reactors, nuclear-powered aircraft carriers, nuclear submarines and space vehicles as well as medical materials due to their excellent nuclear properties and biocompatibility. Zirconium alloys serving in harsh environments are also facing the risk of corrosion failure. Due to the special characteristics of the service environment of the material itself, it is more difficult to simulate and test zirconium alloy corrosion, and to get effective answers to many questions. The corrosion of zirconium alloys includes uniform corrosion, nodular corrosion, stress corrosion and microbial corrosion. Its corrosion is also affected by the material composition, heat treatment process, surface roughness, oxide film composition, pH value of the solution, irradiation, thermal and hydro chemical environments as well as temperature, and other factors, and the protective measures include coatings and corrosion inhibitors and other ways. To further improve the corrosion resistance of zirconium alloys, it is suggested that in the future the study should be conducted in the following aspects: 1) The concentration of solid-solution elements in the zirconium alloy matrix; 2) The type of second-phase elements, grain size and distribution; 3) The growth mechanism of the oxide film; 4) The mode of bacterial attachment and the growth behaviors of the biofilm.

Keywords

• metallic material; zirconium alloy; nuclear industry; seawater corrosion; microbiologically influenced corrosion; protective measures