Effect of Cr on corrosion behavior of Zr-0.3Cu alloy in 360 °C/18.6 MPa/ 0.01 M LiOH aqueous solution

Abstract:

Zr-0.3Cu-xCr (x=0.2, 0.5, 1.0, wt.%) alloys were prepared to investigate the effect of Cr on the corrosion behavior of Zr-0.3Cu alloy in 360 ℃/18.6 MPa/0.01 M LiOH aqueous solution. The results showed that with the increase of Cr content, the number of ZrCr2 secondary phase particles (SPPs) increased, while the number of Zr2Cu SPPs were nearly unchanged. After exposure to the aqueous solution, the corrosion resistance of Zr-0.3Cu-0.2Cr alloy was relatively high compared to other alloys probably due to the thick ZrO transition layer at the oxide/matrix interface. When the Cr content was higher than 0.5 wt.%, the number of SPPs increased, which can generate more defects like micropores and microcracks during oxidation, and consequently, accelerate the corrosion of Zr-0.3Cu-xCr alloys.

Key words:zirconium alloy, Cr addition, microstructure, corrosion resistance, secondary phase particle