Fe-C-S和Fe-C-P三元熔体中组元的活度

ACTIVITY OF COMPONENTS IN Fe-C-S and Fe-C-P TERNARY MELTS

通过实验测定了Fe-C-P熔体中碳溶解度和磷浓度间的关系,得到1350℃ Xc=0.1908-0.761xp1400℃ Xc=0.1912-0.750xp 应用前人的研究结果,换算出了Fe-C-S熔体中类似于Fe-C-P系的结果,即1350℃ Xc=0.1890-0.851xs 依据上述关系式和已知Fe-j熔体的性质,在碳等活度(饱和状态)条件下,建立了三元熔休中碳活度系数的ε表达式,并求出相应的一、二阶活度相互作用系数值。 再根据三元系中两溶质元素相互作用系数间的倒易关系,求出溶质元素浓度较高的Fe-C-P和Fe-C-S三元熔体中,硫、磷活度系数和组成间的二次方程式(铁水预处理温度1300～1450℃):lnyp = lny_p~°+ 9.50xy - 4.75x_p^2 + 13.38xc-4.28x_c^2 - 41.18XcXplnys = lny_s~°- 4.20Xs + 2.10x_s^2 + 15.23xc-4.29x_c^2 - 68.

In this paper, the solubility of carbon :was studied as a function of the concentrations of phosphorus and sulphur in Fe-C-P and Fe-C-S melts respectively. For phosphorus, this was done experimentally in a MoSi2 resistance furnace. The following results were obtained:at 1350 ℃ xC=0.1908-0.761·xP at 1400 ℃ xC=0.1912-0.750·xPThe carbon solubility as a function of the sulphur content in Fe-C-S melts had already been investigated by others and was available in the literature.By using the relations mentioned above and already known coefficients for Fe-C-P and Fe-C-S melts, relations between the activity coefficient of carbon and the concentrations of carbon and phosphorus or sulphur could be established.With the knowledge of the interaction coefficients for carbon, interaction coefficients for phosphorus and sulphur can be obtained. They could then be used to establish the following expressions for the activity coefficients for phosphorus and sulphur:lnγP=lnγPo+9.50 xP-4.75 xP2+13.38 xC-4.28 xC2-41.18xCxPlnγS=lnγSo-4.20 xS+2.10 xS2+15.23 xC-4.29 xC2-68.29 xCxS