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(-81500/RT )   1823 to 1923 K

at lower oxygen content than 0.025 mass% and lower aluminum content than 1.4 mass%. 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 =(N_AlD_Fe^S+N_FeD_Al^S)(1+_{d lnNAl}^{d lnγ_Al})

The self diffusivities of Fe and Al in the equation are obtained, respectively as

D_Fe^S(m²/s)=9.48×10^-4 exp(-145000/RT )
D_Al^S(m²/s)=1.54×10^-6 exp(-96000/RT )