RATE OF DECARBURIZATION OF FE-CSAT MELTS BY H2O AT 1523 AND 1873-K

The rate of decarburization of carbon-saturated iron by H2O gas at 1523 and 1873 K was measured as a function of sulfur content. The measurements were made under conditions for which the gas phase mass transfer is negligible or a reasonable correction for its effect can be made. The measured rates are consistent, with the rate-controlling reaction being the dissociation of H2O on the surface. Sulfur was found to significantly decrease the rate. The rate constant for the dissociation of H2O on iron is considerably higher than those for the dissociation of CO2 and N2 on liquid iron; about 2 to 3 times higher than CO2 and 300 to 600 times higher than for N2 at 1873 K. The practical significance of the present results relevant to steel ladle processing and iron bath smelting is briefly discussed.