A kinetic study has been made on the reaction between a silica-containing alumina graphite refractory and low carbon molten steel by measuring mass loss of the refractory heated at 1100-1600°C and Si content of the molten steel at 1600°C where the refractory was immersed.
The results are summarized as follows:
(1) The reaction in the refractory is controlled by the diffusion of SiO gas and CO gas through the pores in the refractory.
(2) The rate of reaction between the refractory and the molten steel is controlled by diffusion of the SiO gas and CO gas through the pores of oxide film formed at the refractory-molten steel interface.
(3) The rate of the reaction between the refractory and the molten steel is faster in the Ti-killed molten steel than in the Al-killed molten steel sand exhibits steel grade dependence. This steel grade dependence can be ascribed to the differences in the gas permeability through the oxide film formed at the refractory-molten steel interface between the Al-killed molten steel and the Ti-killed molten steel.