Rate of decarburization of iron-carbon melts: Part I. experimental determination of the effect of sulfur

Abstract

The kinetics of decarburization of iron-carbon melts with CO-CO2 gas mixtures were investigated at 1700 ° using the levitation technique. The influences of different experimental variables on the decarburization kinetics were determined. It was found that sulfur has a clear and reproducible retarding effect on the decarburization of iron-carbon melts; and this effect is most pronounced at sulfur concentrations in the range of 0 to 0.05 wt pct. The initial carbon concentration has no discernible effect on the decarburization kinetics. Melts containing 2.48 wt pct C and 0.92 wt pct C initially were found to decarburize at virtually identical rates until a substantial portion of the carbon was removed. The decarburization rate of a melt with a specified initial carbon content was found to remain essentially constant until the carbon content fell to a characteristic level below which the rate tended to level off. The partial pressure of CO2 of the gas mixture has a marked effect on the decarburization kinetics. The flow-rate of the gas mixture has a small but finite effect on the rate of decarburization.