Microstructural evolution of intermetallic phase precipitates in Cr-coated Zirconium alloy cladding in high-temperature steam oxidation up to 1400 °C

Abstract

The steam oxidation on the Cr-coated Zry cladding was studied up to 1400 °C to understand the oxidation behavior under the accidental conditions. The double-sided oxidation test showed that Cr coating can protect Zry cladding till 1200 °C/5 min. However, at T ≥ 1300 °C/5 min, Cr coating can no longer protect Zry cladding and the intermetallic phase of the Zr(Cr, Fe)2 phase that precipitated within the Zry formed as globule microstructures. In addition, the transition of the intermetallic phase within the Zry substrate from the solid to liquid phases was observed, where it was determined at 1400 °C/30 min within the ZrO2 phase.