C-O反応を伴う溶鉄の窒素吸収について

Abstract

The effect of carbon-oxygen reactions on the rate of nitrogen absorption in liquid iron were studied under N2-O2 and N2-CO2 gas mixtures.It was confirmed that the experimental results on the decarburization of liquid iron agreed well with those obtained by several investigators.On the other hand, the simultaneous absorption of nitrogen in liquid iron shows a peculiar behavior as compared with the absorption without carbon -oxygen reaction at the interface. Namely, it was observed that the nitrogen concentration in liquid iron does not reach to equilibrium with nitrog en partial pressure in bulk gas phase, although the rate of nitrogen absorption in the initial period is rather rapid. This may be resulted from the decrease of nitrogen partial pressure at g as-metal interface due to the evolution of carbon monoxide from liquid iron. In this case, the nitrogen absorption may be controlled mainly by the transfer of nitrogen in liquid iron and also in gas phase.When the oxygen concentration of gas phase becomes nearly 30 percent, the effect of the absorbed oxygen at the gas-metal interface becomes more predominant in nitrogen absorption than that of d ecrease of nitrogen partial pressure at interface. When liquid iron contains sulphur, the effect of the adsorbed sulphur at the interface may also be predominant similarly to the case of 30% O2-N2 gasmixture.