Influence of Cr and Al contents on the corrosion resistance of FeCrAl coatings on Zry-4 under simulated pressurized water reactor conditions

Abstract

This study explores the impact of Cr (13 wt%, 23 wt%) and Al (3 wt%, 5 wt%, 7 wt%) content on the corrosion resistance of FeCrAl coatings deposited on Zry-4 substrates via magnetron sputtering, under simulated pressurized water reactor (PWR) conditions (360 °C, 18.6 MPa). The findings reveal that increasing Cr and Al content enhances the density and mechanical strength of the coatings, with Cr playing a more dominant role in corrosion resistance. Coatings with 23 wt% Cr exhibited significantly better corrosion resistance than those with 13 wt% Cr, primarily due to reduced Fe₂O₃ formation and the development of a denser FeFe_2-x-yCr_xAl_yO₄ spinel layer, which effectively blocks the outward diffusion of Fe and the penetration of corrosive medium. The first principles simulation of H₂O adsorption on FeCrAl surface further verified the excellent stability and corrosion resistance of chrome-rich coating in aqueous environment. This study underscores the critical importance of Cr in optimizing FeCrAl coatings for PWR conditions, offering valuable insights for their application in nuclear systems.