Abstract: Crystallization kinetics of Fe₅₂Cr₁₈Mo₇B₁₆C₄Nb₃ alloy was evaluated by X-ray diffraction (XRD), differential
scanning calorimetric (DSC) tests and transmission electron microscopy (TEM) observations in this research
work. In effect, crystallization and growth mechanism were investigated by using DSC tests at four different
heating rates (10, 20, 30, 40 K/min). Results showed that a two-step crystallization process occurred in
the alloy in which α-Fe and Fe₃B phases were crystallized, respectively in the structure after heat treatment.
Activation energy for the first step of crystallization, i.e. α-Fe was measured to be 421 and 442 kJ/mol
according to Kissinger-Starink and Ozawa models, respectively. Further, Avrami exponent calculated from
DSC curves was 1.6 and a two-dimensional diffusion controlled growth mechanism with decreasing nucleation
rate was observed in the alloy. Moreover, it was known from the TEM observations that crystalline α-Fe phase
nucleated in the structure of the alloy in an average size of 10 nm and completely mottled morphology.

Key words: Bulk metallic glasses (BMGs), Structural amorphous steels (SASs), Avrami exponent, Crystallization and kinetic models