OXIDATION OF ALUMINUM IN MOLTEN IRON BY I MPURITY OXYGEN IN ARGON

Oxidation rate of aluminum in molten iron by impurity oxygen in argon is observed in order to take information on evolving nonmetallic inclu sion as well as nozzle blocking of continuous casting apparatus. The a luminum is oxidized by argon containing oxygen above 10(-14) Pa in oxy gen partial pressure. Rate determining step of the oxidation in the ca se of no convection is diffusion process in an oxide layer generated a t the surface of the molten iron. In the case of specimen with convect ion, the step is chemical reaction process. The rate is expressed as a second order reaction for aluminum content. Apparent activation energ y of the reaction is -1224 KJ/mol. It is discussed that the apparent a ctivation energy corresponds to enthalpy change of the oxidation react ion.