1994 年 34 巻 8 号 p. 657-662
A kinetic study has been made on decarburization reaction of molten iron of low carbon and oxygen concentrations with solid oxides. A new degassing method, namely Vacuum Suction Degassing (VSD) method, was applied to decarburize molten iron to an ultra-low carbon concentration. A porous oxide tube, the inside of which was evacuated, was immersed into molten iron. The initial carbon concentration was varied between 30 and 110 ppm. The initial oxygen concentration was below 50 ppm. The experiments were performed under Ar atmosphere (1.01×105 Pa). The experimental temperature was 1853 K.
The VSD method can greatly increase the rate of decarburization of molten iron and the carbon concentration decreases to a very low value of a few ppm. The rate of decarburization with an Al2O3-SiO2 tube is higher than that with an Al2O3 tube. Increase in gas permeability of a porous tube enhances the decarburization reaction. The apparent rate constant of decarburization at the porous tube-molten iron interface with evacuation in the porous tube is about 10 times larger than that without evacuation.
