Corrosion and microstructural characteristics of Zr–Nb alloys with different Nb contents

To improve their corrosion resistance and mechanical properties, Nb is added to most of the advanced Zr-based alloys. So, in this study, a systematic investigation was performed on Zr–xNb alloys (x = 0.1–2.0 wt%) to establish the optimized Nb content and annealing temperatures which were applied during manufacturing process. A corrosion resistance of Nb-containing Zr alloys was considerably affected by the Nb content as well as annealing temperature. The good corrosion resistance was obtained when the Nb content was controlled to be 0.2–0.3 wt% and the annealing temperature of the high Nb-containing alloys during the manufacturing process was performed at 570 °C. From the microstructural investigations by using TEM/EDS, the corrosion resistance was controlled by the Nb solubility in alpha Zr and the type of β-phases which were determined by the annealing temperature.