In situ synchrotron radiation diffraction study of low carbon steer duringion nitriding

The volume close to the surface of materials subjected to ion implantation or ion diffusion exhibits structural transformations that are usually studi ed by x-ray diffraction. In order to characterize the kinetic aspects oft s tructural transformations in law carbon AISI 1010 steel during ion nitridin g, an in situ synchrotron radiation diffraction study was performed. An exp erimental set-up, a specially designed reactor, was constructed for x-ray m easurements in real time. The variation in the lattice parameter with time of the initial FE-alpha phase was attributed to the heating effect produced by the action of an electric discharge during the first stages of the proc ess. The analysis of the x-ray diffraction patterns indicates the formation of several iron nitrides. The Fe3N phase exhibits a progressive decrease i n the interplanar distances, which is clearly a different behaviour with re spect to the other observed phases, even considering a phase with nearly th e same stoichiometry.