Chemically induced solidification : a new way to produce thin solid-near- net shapes

In-situ observation of the solidification of high carbon steel (4 wt% C) through decarburization has been carried out as a feasibility study into reducing high power usage and high CO2 production involved in steel making. Decarburization has been carried out under both air and pure N2 atmospheres at temperature of 1573K (1300 °C) and 1673K (1400 °C). A solidified shell of around 500μm was formed with carbon concentrations reduced down to 1% in as short as 18s

Decarburization of Levitated Fe-Cr-C Droplets by Carbon Dioxide

Experiments have been conducted at 1873K (1600°C) to study the kinetics of decarburization of Fe-Cr-C levitated droplets containing 10, 17 and 20 wt pct Cr using argon-carbon dioxide gas mixtures containing up to 30 pct CO2, at flow rates of 100, 1000, 3000 and 12200 mL per min. It was found that chromium did not have a strong influence on the kinetics of decarburization while showing only minor effects on the extent of carbon removal. The results indicate that, for high carbon concentrations in the melt, the decarburization rates were controlled by mass transfer in the gas phase. Conventional formulation of governing mass transport numbers did not adequately describe the experimental observations made in this work. The observed rates are consistently higher than the values predicted using either the Ranz-Marshall correlation or the Steinberger-Treybal equation. A new correlation has been proposed to express the decarburization kinetics of levitated droplets for gas-flows in the range of Reynolds numbers between 2 and 100. The experimentally-derived model was found to be in excellent agreement with rate data derived from studies conducted by other researchers using levitated droplets.Appreciation is expressed to the Natural Sciences and Engineering Research Council of Canada who provided funding in support of this project