THERMODYNAMIC PROPERTIES OF ALUMINA-SATURATED IRON-CARBON-BISMUTH ALLOYS

Using direct and indirect equilibration methods, the solubilities of i ron in molten bismuth and those of bismuth in molten iron-carbon alloy s have been measured over the temperature range 1473-1873 K. The Henri an behaviour of bismuth in molten ferrous alloys allows the calculatio n of its activity coefficient, which in turn facilitates modelling as a function of temperature and carbon content, using the unified intera ction parameter formalism developed by Pelton and Bale. The modelling results generate the expression: ln gamma(Bi) = (15830/T - 1.578) + (- 1.124.105/T + 74.762)X-C + (7.823/T + 3.69)X-C(2). A model has also be en developed expressing bismuth content in molten iron-carbon alloys a s a function of temperature and composition: log(%Bi) = (-2624.5/T + 0 .066) + (22522/T - 9.59)(%Bi) + (-2269.5/T + 1.494)(%C) + (846/T - 0.5 4)(%C)(2).