Decarburization of ultra-low carbon steel by vacuum levitation

Vacuum levitation experiments have been conducted to study the decarburization kinetics of levitated steel droplets in order to determine the factors and relationships which control the rate of decarburization especially at C levels below 30 ppm. It was found from the experiments that (1) vacuum chamber pressure had a significant effect on the rate of decarburization when the carbon content was below 35 ppm; (2) sulfur did not show any significant effect on the rate of decarburization due to the strong stirring inside the droplet caused by magnetic levitation field; (3) the rate of decarburization of levitated droplets was 3 ppm/sec at (C) = 30 ppm which was 40 times higher than the overall rate of decarburization in the RH process at (C) 30 ppm; (4) high initial oxygen contents improved the rate of decarburization at high carbon contents.The following suggestions are made: (1) increase the amount of liquid steel droplets without increasing the size of the droplets; (2) increase the fraction of the amount of decarburization reaction inside the molten steel by gas and powder injection; (3) further reduce the partial pressure of CO and CO$ sb2$ gas in the gas phase. (Abstract shortened by UMI.