Improved Characterization of Aqueous Corrosion Kinetics of Zircaloy-4

摘要

In the analysis of the posttransition corrosion regime of zircaloys in a water environment it has typically been assumed that the cycles occurring after the first cycle (pretransition) could be approximated by a constant rate. Recently, long-term testing of Zircaloy-4 has shown this assumption to be nonconservative. Posttransition rates are seen to increase with increasing weight gain or time until a steady state posttransition rate is achieved. The corrosion of Zircaloy-4 in a water environment is, therefore, now seen to have a transitory regime in addition to the pre-transition and steady state posttransition regimes. The mathematical description of this transitory regime is presented. (ERA citation 07:050863)