The Cr-Fe-Nb ternary system: Experimental isothermal sections at 700 degrees C, 1050 degrees C and 1350 degrees C

The Cr-Fe-Nb system is an important constituent system in the development of Laves-phase reinforced steels. It contains two Laves-phase polytypes, i.e. C-14-Fe2Nb and C-15-Cr2Nb. While the first forms a substantial ternary solid solution with Cr, the latter only shows a limited solubility for Fe. The phase equilibria in the Cr-Fe-Nb system are shown in three isothermal sections at 700, 1050 and 1350 degrees C. Scanning electron microscopy coupled with energy dispersive X-ray analysis (SEM/EDX), X-ray diffraction (XRD) and electron back scatter diffraction (EBSD) were used to determine the phase equilibria from which the isothermal sections were constructed.