Investigation of oxide layers formed on Zircaloy-4 coarse-grained specimens corroded at 360°C in lithiated aqueous solution

Oxide Layers on (0001) Plane of Zircaloy-4 After Corrosion at 360 °C in Lithiated Aqueous Solution

“…The undulating wavy O/M interface can be found in Fig. 1, and the growth of the oxide layers is in a manner of alternating forward [17]. Figure 3 shows the inner surface of the oxide layers formed on the grain surface with an orientation near (0001) after 70 days exposure.…”

“…In this study, coarse grains can be grown by annealing the specimens at 800°C in the high-temperature alpha-phase region after water quenching from b-phase region. The details of the specimen preparation technique are described elsewhere [7,17]. Specimens with coarse grains of 0.2-0.8 mm in diameter were obtained finally.…”

“…As a part of the systematic investigation, the current study only aimed to address the microstructure and crystal structure of oxide layers at the O/M interface formed on a coarse grain surface with (0001) orientation during corrosion tests in autoclave at 360°C and under 18.6 MPa in 0.01 mol/L LiOH aqueous solution. The study of (10 " 10) orientation has been reported in previous paper [17].…”

Influence of γ-irradiation on the transport kinetics of hydrogen in pre-transition oxidized Zircaloy-4 at room temperature

“…The pre-oxidation in representative PWR primary water has been performed by exposition of the specimen to synthetic PWR primary water (2 ppm Li (LiOH), 1000 ppm B (HBO 3 ), 35 cc/kg H 2 , less than 5 ppb O 2 ) at 184 bars and 633 K for 54 days [8,20,21], in order to reach an oxide thickness in the range 1300e1700 nm, with an oxide structure representative of the pre-transitory regime. Oxide thicknesses were estimated thanks to weight gain measurements, presented in Table 1, and are in good agreement with literature [8,20,21,41]. The oxide was characterized by SEM and TEM observations (see Section 3).…”

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

“…However, the Fukushima accident demonstrates the importance of understanding the oxidation behavior of zirconium alloys, as they shield the radioactive materials (i.e., uranium, fission gas) and the degradation of the zirconium cladding directly contributes to severe accidents in nuclear power plants. Furthermore, zirconium oxide forms at the water-metal interface, and its structure and phase determine its mechanical properties [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. Therefore, to ensure the safety of the nuclear power reactors, the corrosion mechanism and sustainability of the zirconium based alloy materials must be understood.…”