Effects of Boron, Chromium, Molybdenum, Niobium, Tantalum, and Tungsten on the Activity Coefficient of Manganese in Liquid Iron Alloys

Abstract

The effect of alloying elements on the activity coefficient of manganese in liquid iron alloys has been measured using a closed chamber method with an alumina capsule. The results obtained are summarized as follows:
(1) The results of interaction parameter e_Mn(^X) in liquid iron alloys at 1570°C are given by
(2) Enthalpy coefficient h_Mn(^X) and entropy coefficient S_Mn(^X) are obtained for X=B, Nb, and W as follows:
(3) A linear relation with the correlation coefficient -0.83 is observed between ε_Mn(^X) and n_{X, eff.}.
(4) The relations η _Mn(^X)=120ε_Mn(^X) and σ_Mn(^X)=63.1ε_Mn(^X) obtained in the present work yield the quantitatine relation between ε_Mn(^X) and temperature, the very low characteristic temperature of the solution, and the value Tσ_Mn(^X)/η_Mn(X) being close to unity. These relations and quantities are very different in magnitude from those of ε_N(^X) or ε_H(^X).