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 degrees 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 beta-phases which were determined by the annealing temperature. (C) 2007 Elsevier B.V. All rights reserved.