Abstract
Wide applications of zircaloys, stainless steels and their interactions in nuclear reactors
require the knowledge on phase stability and thermodynamic property of the Fe-Cr-Zr system.
This knowledge is also important to develop new Zr-contained Fe-Cr ferritic steels. This work
aims at developing thermodynamic models for describing phase stability and thermodynamic
property of the Fe-Cr-Zr system using the Calphad approach coupled with experimental study.
Thermodynamic descriptions of the Fe-Cr and Cr-Zr systems were either directly adopted or
slightly modified from literature. The Fe-Zr system has been remodeled to accommodate recent
ab-initio calculation of formation enthalpies of various Fe-Zr compounds. Reliable ternary
experimental data and thermodynamic models were mainly available in the Zr-rich region.
Therefore, selected ternary alloys located in the vicinity of the eutectic valley of β(Fe,Cr,Zr) and
(Fe,Cr)2Zr laves phase in the Fe-rich region have been experimentally investigated in this study.
Microstructure has been examined by using scanning electron microscope, energy-dispersive Xray
spectroscopy and X-ray diffraction. These experimental results, along with the literature data
were then used to develop thermodynamic models for phases in the Fe-Cr-Zr system. Calculated
phase equilibria and thermodynamic properties of the ternary system yield satisfactory
agreements with available experimental data, which gives the confidence to use these models as
building blocks for developing a Zr, Fe and Cr contained multicomponent thermodynamic
database for broader applications in nuclear reactors.
