EQUILIBRIUM BETWEEN YTTRIUM AND OXYGEN IN LIQUID-IRON AND NICKEL

In order to investigate the equilibrium between yttrium and oxygen in liquid iron and nickel, the deoxidation of yttrium in liquid iron and nickel saturated with yttria has been measured at the temperature ranges from 1600-degrees-C to 1700-degrees-C using the sampling technique. The effect of temperature on the equilibrium constant of the deoxidation reaction in liquid iron was found to be: log K(Y(Fe)) (= a(Y)2.a(O)3) = -36160/T+7.33 while the deoxidation product of iron, log K(Y)(Fe))' (= [%Y]2[%O]3), was expressed as follows: log K(Y(Fe))' = log K(Y(Fe)) - (-17350/T+3.14) (3[%Y] + 11.1[%O]) 0.02< [%Y]<0.11 by the use of the interaction parameter, e(O)(Fe))Y = - 17350/T+3.14. The temperature dependence of the equilibrium constant for the deoxidation of nickel, log K(Y(Ni)), was given by the expression: log K(Y(Ni))' = -36250/T+6.36 Besides, the deoxidation product of nickel was represented to be: log K(Y(Ni))' = log K(Y(Ni))+6.47(3[%Y]+11.1[%O]) 0.01< [%Y]<0.11 with the interaction parameter, e(O(Ni))Y = -6.47.