An improved thermodynamic modeling of the Fe-Cr system down to zero kelvin coupled with key experiments

► We present a possible way to bridge CALPHAD and ab initio calculations. ► Thermodynamic modeling of the Fe-Cr system is performed down to 0 K. ► A sign change of magnetic ordering energy of mixing rather than enthalpy of mixing is found in bcc alloys at 0 K. ► Phase separation in the Fe-Cr alloys is studied by atom probe tomography. ► Reasonable chemical spinodal curve of the Fe-Cr system is predicted.