In this report Dr Massih presents correlations for creep in different phases of zirconium alloys and also presents a general solution to the difficulty of accurately describing the material properties in phase transition for several zirconium alloys. Based upon superplasticity relations, models are adapted to fit with experimental data for materials in transition regions. The creep models are developed for both previous generations of zirconium alloys (Ziracaloy-2 and Zircaloy-4) and upgraded to fit for Zr1%Nb materials. The adaptations are successful since a good agreement between experimental data and model computation has been reached, based on a better understanding of the physical phenomena acting in the materials.
