Effect of aluminum and oxygen content on diffusivity of aluminum in molten iron

Abstract

The diffusivity of aluminum in molten iron has been obtained with the capillary reservoir method. It is given as D(m2/s) = (1.00±0.11)×10-6 exp(-81 500/RT) 1 823 to 1 923 K at lower oxygen content than 0.025mass% and lower aluminum content than 1.4mass%. If the oxygen content is higher, the diffusivity decreases apparently with the oxygen content. The effect of oxygen on aluminum diffusion is well interpreted by the counter current diffusion model. The effect of aluminum content is well expressed by the Darken's equation. D=(NAlDFes+NFeDAls)(1 + d In γAl/d In NAl) The self diffusivities of Fe and Al in the equation are obtained, respectively as DFes(m2/s)=9.48×10-4 exp(-145 000/RT) DAls(m2/s) =1.54×10-6 exp(-96 000/RT).