Self-diffusion of iron in α-phase of iron and Fe-Cr alloys

In the present paper the self-diffusion coefficients of iron in α-iron and in Fe-Cr alloys in the temperature range 660–890°C and in the concentration interval 0–11.8 wt.% Cr were determined. The residual activity method has been applied using the isotope 59Fe. Special attention was payed to the close neighbourhood of the Curie temperature. The obtained data confirmed the effect of ferromagnetic ordering on the iron self-diffus ion in pure Fe and in all the investigated Fe-Cr alloys. An empiric relation was found between the excess free activation enthalpy of diffusion and the spontaneous magnetization that yields a picture about the magnetic ordering of the used materials.