A superior corrosion behavior of Zircaloy-4 in lithiated water at 360 °C/18.6 MPa by β-quenching

Abstract

To further understand the mechanism on the heat-treatment effect on corrosion behavior of Zircaloy-4, β-quenched and recrystallized specimens are corroded in an autoclave with 0.01 M LiOH aqueous solution at 360 °C/18.6 MPa. Results show that the β-quenched specimen possesses excellent corrosion resistance, the weight gain of which is consistently comparable to that of ZIRLO and N18 alloys during 529 days exposure, while the recrystallized specimen exhibits accelerated corrosion rate after 100 days exposure. The increase of the supersaturated solid solution contents of Fe and Cr in α-Zr matrix is responsible for the improvement of corrosion resistance by β-quenching treatment. The fracture surface and inner surface morphology of oxide films indicates that β-quenching treatment significantly slow down the development of pores to cracks in oxide films and reduces the uneven growing tendency of the oxide, which is related to the corrosion behavior.