The Decarburization Mechanism for Stainless Steel Melt by Ar-O2 Ascending Gas Bubble
1977 Volume 63 Issue 13 Pages 2100-2109
Details
1977 Volume 63 Issue 13 Pages 2100-2109
The decarburization mechanism for stainless steel melt by Ar-O2 ascending gas bubbles was studied under atmospheric and reduced pressures in a laboratory-scale induction furnace. Experimental results are summarized as follows:
(1) The rate of decarburization is divided into two stages. In the first stage the rate is constant, being independent of the carbon content, and in the second stage it gradually decreases with the lowering of the carbon content in the bath.
(2) In this experiment, the critical carbon content at 1600°C is higher than the C-Cr equilibrium point that is determined by the Pco, and the cridcal carbon content at 1700°C is slightly higher than the carbon content at which the rate controlling step varies from the gas phase control into the carbon diffusion control at the gas bubble-metal interface.
(3) Regarding chromium yield the submersion depth is a very important factor for reduction of chromium oxide which is formed by Ar-O2 gas bubbling. The temperature of the melt and Ar/O2 ratio are also important opperational factors for effective decarburizing without an excessive chromium loss.
(4) Ar-O2 gas bubbling under reduced pressure is a very effective method for decarburizing to extra low carbon content (C<0.004%) without an excessive chromium loss.
