Effects of gaseous hydrogenation on crystallization behavior of melt-spun Mg63Pr15Ni22 amorphous ribbons have been investigated. The crystallization peak temperature Tp1 shifted to higher temperature with increasing heating rate for the un-hydrogenated Mg63Ni22Pr15 metallic glass, however, it is nearly unchanged for the hydrogenated sample. The present work indicates that the crystallization
is a nucleation-and-growth process for the un-hydrogenated Mg63Ni22Pr15 metallic glass. However, the crystallization of hydrogenated sample begins with nucleation and then diffusion-controlled
growth takes place.