In-situ Raman Spectroscopy Investigation of Surface Films Formed on New Zirconium Alloys in High-temperature and High-pressure Water

Corrosion test and in-situ Raman spectroscopy, characterization test for SZA-4, SZA-6 and ZIRLO alloys were carried out using the established high temperature and high pressure circulating water corrosion test system, in situ observation autoclave and Raman spectroscopy characterization system. The corrosion test solution was an aqueous solution containing 1 200 mg/L H₃BO₃ + 2 mg/L LiOH. The results show that the Raman spectrum peaks of the three alloys were located near 350,390,486,644,700,750,770 cm^-1. And Raman peaks were derived from oxides formed on the surface of zirconium alloy:cubic zirconium dioxide (c-ZrO₂), tetragonal zirconium dioxide (t-ZrO₂), monoclinic zirconium dioxide (m-ZrO₂) and non-crystal oxide. The time of occurrence of m-ZrO₂ in the surface oxide film of the three alloys was different, m-ZrO₂ was first appeared in the surface oxide film of ZIRLO alloy, followed by SZA-6 alloy, and the latest was SZA-4 alloy.