Phase transformation of oxide film in zirconium alloy in high temperature hydrogenated water

• Published in: Corrosion science 2015-10, Vol.99, p.134-144
• Main Authors: Kim, Taeho, Kim, Jongjin, Choi, Kyoung Joon, Yoo, Seung Chang, Kim, Seunghyun, Kim, Ji Hyun
• Format: Article
• Language: English
• Subjects: A. Alloy; A. Zirconium; B. Raman spectroscopy; B. TEM; C. Oxidation
• ISSN: 0010-938X; 1879-0496
• DOI: 10.1016/j.corsci.2015.06.034

•Zirconium alloy, ZIRLO was used for the oxide characterization in PWR primary water.•Dissolved hydrogen concentration was changed to see the effect on the oxide formation.•Changes of oxide chemistry and phase were analyzed by in-situ Raman spectroscopy.•Oxide phase stability was affected by the change of dissolved hydrogen concentration.•Stresses due to OH− concentration change mainly cause the oxide phase transformation. The effect of the variation of the dissolved hydrogen concentration on the oxide phase transformation under high-temperature hydrogenated water conditions was investigated using in situ Raman spectroscopy. The Raman spectrum in 50cm3/kg of dissolved hydrogen concentration indicated the formation of monoclinic and tetragonal zirconium oxide at the water–substrate interface. As the dissolved hydrogen concentration decreased to 30cm3/kg, the Raman peaks corresponding to the zirconium oxide phase changed, indicating an oxide phase transformation. And, the results of SEM and TEM analyses were compared with those of in situ analyses obtained for the oxide structure formed on the zirconium alloy.