Experimental determination of phase equilibria in the Fe–Nb–V ternary system

The phase equilibria in the Fe–Nb–V ternary system were investigated by means of optical microscopy, electron probe microanalysis and X-ray diffraction. Four isothermal sections in the Fe–Nb–V ternary system at 1000 °C, 1100 °C, 1200 °C and 1300 °C were firstly experimentally established. Present experimental results indicate that: (1) there is a large (Nb, V) continuous bcc solid solution; (2) there are the larger solubilities of V in the FeNb and Fe2Nb phases. The newly determined phase equilibria in this system will provide important support for the development of hydrogen storage materials and microalloyed steels.