溶融Fe-Mn-C合金の熱力学的活量

抄録

High carbon ferro-manganese alloys are used to produce high manganese steels for non-magnetic materials. During the decarburization of the high manganese hot metal, oxidation loss of manganese occurs concurrently. To minimize the oxidation loss of manganese and to establish an optimum dacarburization process, it is important to know the thermodynamic properties of the liquid Fe-Mn-C alloys with high Mn concentration and wide concentration range of carbon.
In the present study, measurements were carried out of the activity of Mn in liquid Fe-C-Mn alloys. Distribution equilibrium of Mn between Fe-Mn-C alloys of different C concentration via a liquid Ag-Mn alloy bath was employed to determine the activity of Mn.
The experimental concentration range of Mn was from 0 to 45 mol% and that of C was 0 to saturation and the experimental temperatures were 1736, 1773 and 1823K. The activity coefficient on the base of lattice ratio of manganese was found to be expressed properly with up to the second order terms by the use of lattice fraction as the concentration of solute elements. The interaction of Mn and C of liquid Fe-C-Mn ternary alloys were given as the functions of temperature and composition of the alloy.
The activity coefficient of C was also derived from the obtained parameters.