Corrosion Behavior of New Type Zirconium Alloys in Superheated Steam

The microstructure and corrosion behaviors of Zr-xFe-yCr alloys have been investigated in the superheated steam of 500℃/10.3 MPa. The results show that the composition of Zr-Fe-Cr alloy after vacuum melting, β quenching, vacuum covered hot and cold rolling, and vacuum annealing are α-Zr base and dispersed Zr（Cr, Fe）2 particles. A nodular corrosion takes place on the Zr-4 and Zr-0.2Fe-0.1Cr specimens, but uniform corrosions occur on the Zr-Fe-Cr alloys with appropriate Fe and Cr, in the 500℃ and 10.3 MPa superheated steam. The Zr-1.0Fe-0.6Cr specimens have the best corrosion resistance, and its corrosion resistance in the superheated steam is better than that of N18 and Zr-4 alloys. The alloy specimens with different contents of Fe and Cr are with quite different corrosion resistances, which indicates that the composition of zirconium alloys is the key factor to improve the corrosion resistance in 500℃/10.3 MPa.