Effect of microstructure on the corrosion resistance of Zr-Sn-Nb-Fe zirconium alloy

After being treated in different ways, Zr-Sn-Nb-Fe alloy specimens were exposed in 0.01mol·L -1 LiOH aqueous solution at 350℃, 16.8MPa. The examination of microstructures and second phase particles (SPPs) of these specimens was carried out by high-resolution transmission electron microscopy (HR-TEM). The specimens treated at 800℃ for 1 h before the final cold rolling have better corrosion resistance than that treated at 680℃ for 5 h, and the specimens treated at 500℃ for 30 h after the final cold rolling have better corrosion resistance than that treated at 560℃ for 10 h. TEM examination shows that the SPPs existing in the 800℃/500℃ treated specimen, which has the best corrosion resistance for 10 h, contain much more Nb element,and result in the reduction of niobium content in αZr solid solution.