Activity of Carbon and Oxygen in Liquid Iron

Abstract

The equilibrium of CO-CO2 gas mixture with carbon and oxygen dissolved in liquid iron was studied in the range from a dilute solution to a concentration with 2·5% carbon at 1460, 1560, 1660 and 1760°CThe results obtained gave the following equatians:C+CO2=2CO…… (1)logK1 (=Pcoco2/Pcoco2·aC) =-7, 558/T+6·765ΔF°1=34, 580-30·95TO+CO=CO2…… (2)logK2 (=Pcoco2/Pcoao) =8, 718/T-4·762ΔF°2=-39, 880+21·78TC+O=CO…… (3)logK3 (=Pco/ac·ao) =1, 160/T+2·00ΔF°3=-5, 310-9·16TThe relationship between the activity coefficient of carbon or oxygen, and the concentration of carbon was expressed by the following equations, where the mole fration of carbon was below 0·09Nc:logγ (c) c=6·40Nc……<0·09Nclogf (c) o=-9·05Nc……<0·09NcFrom these results activity coefficient of carbon in liquid iron was evaluated over the whole range of carbon of the Fe-C alloy.