Microstructure and Corrosion Behavior with Nb/Fe Ratio of Zr-based Alloys

摘要

The effect of Nb and Fe addition ratio on the microstructure, corrosion behavior of Zr-based alloys has been performed. The Nb/Fe ratio was controlled to be 0.6 to 7.0 maintaining the same Nb + Fe content in each alloy. The microstructural analysis oil the grain size and the precipitate properity such as area fraction, mean diameter and crystal structure was used for interpreting the corrosion kinetics. The grain size and the precipitate area fraction were not largely affected by the Nb/Fe ratio, but the precipitate mean diameter and the precipitate crystal structure were changed with those of ratios. The corrosion resistance of ternary Zr-Nb-Fe alloys was improved when the Nb/ Fe ratio that controlled the precipitate crystal structure was lower than 1.0. Therefore, it seems that the corrosion behavior was largely affected by the crystal structure of precipitate among the various microstructural characteristics.