EFFECT OF ALUMINUM AND OXYGEN-CONTENT ON DIFFUSIVITY OF ALUMINUM IN MOLTEN IRON

The diffusivity of aluminum in molten iron has been obtained with the capillary reservoir method. It is given as D(m(2)/s)=(1.00+/-0.11) x 1 0(-6) exp(-81 500/RT) 1 823 to 1 923 K at lower oxygen content than 0. 025 mass% and lower aluminum content than 1.4 mass%. If the oxygen con tent is higher, the diffusivity decreases apparently with the oxygen c ontent. The effect of oxygen on aluminum diffusion is well interpreted by the counter current diffusion model. The effect of aluminum conten t is well expressed by the Darken's equation. D=(NAlDFes+NFeDAls)(1+ d ln gamma(Al)/dlnN(Al)) The self diffusivities of Fe and Al in the equa tion are obtained, respectively as D-Fe(s) (m(2)/s)=9.48 x 10(-4) exp( -145 000/RT) D-Al(s) (m(2)/s)=1.54 x 10(-6) exp(-96 000/RT).