Measurement on interaction parameter between CO and Al in molten high Al steel

Nowadays Al is commonly used as deoxidizer and sometimes alloying element. On the other hand, due to the increase in scrap addition, suppress in the concentration of tramp element in molten steel during refining process becomes more important than ever. Co is one of the tramp elements in steel scrap and its content is increasing due to the increase in the production of Co materials world widely. As fundamentals to understand the thermodynamic behaviors of Co in the molten steel containing high Al, the interaction parameter between Co and Al has been measured in this study through a chemical equilibrium method. From the equilibrium composition of the Fe–Co–Al alloy and Ag, the interaction parameter between Co and Al in molten Fe–Co–Al alloy was determined as follows, Al εCo = 7.3±0.9 at 1 823 K, 0< XAl ^Fe < 0.14 By converting the temperature and the reference state, the following values were also obtained, ε_Co ^Al = 6.9±0.8 at 1 823 K e_Co ^Al = 0.060±0.007 at 1 873 K e_Al ^Co = 0.030±0.004 at 1 873 K