Effects of Carbon, Cobalt, Nickel, Silicon, Titanium, and Vanadium on the Activity Coefficient of Manganese in Liquid Iron Alloy

Abstract

A modified closed chamber method has been applied to determine the effect of the alloying element on the activity coefficient of manganese in liquid iron alloy. The results obtained are summarised as follows:
(1) Interaction parameter e_Mn^(X) in liquid iron alloy at 1570°C:
The value of e_Mn^(C) is in fairly good agreement with those of previous investigators obtained by a different method.
(2) Enthalpy coefficient h_Mn^(X) and entropy coefficient s_Mn^(X) defined by Chipman et al. are obtained for X=C and Si as follows:
(3) In consideration of the large discrepancy in e_Mn^(SI)'s of the present authors and previous investigators, it is shown that H₂-H₂O method has a possibility of making considerable errors by the effects of hydrogen, oxygen, and SiO in determination of e_O^(O), e_SI^(SI), and e_O^(SI), which were used to obtain e_SI^(Mn) by the previous investigators.
(4) A regular periodic relation is found between the interaction parameter ε_Mn^(X) and atomic number of the alloying element X.
(5) The interaction parameter εe_Mn^(X) shows a tendency to decrease with increasing the effective number of free electron n_{x, eff} of the alloying element X.