In this paper a DSC study is reported of the behavior of Fe40Ni40P14B6 alloy produced by rapid quenching. The experimental results show that relaxation phenomena can be studied directly from the DSC curves. From these experiments, the spread of the Ec values in the literature is attributed to differences in the quenching rates and the presence of variable number of quenched-in nuclei. It is also shown that the microstructure (number and size of crystals) of the non-isothermally devitrified metallic alloy changes with the heating rate; this is a consequence of the shift of crystallization temperatures and, therefore, of the change of the ratio of nucleation and crystal growth rates.