转炉吹炼中低碳铬铁的热力学分析

利用碳饱和溶解度数据处理的方法,计算了Ｆｅ－Ｃ－Ｃｒ熔体的热力学性质,得到了Ｃｒ对Ｃ的活度相互作用与温度的关系式,并分析了高碳铬铁转炉法吹炼中低碳铬铁时吹氧脱碳的热力学行为。     

碳在纯锰和纯铁熔体中的饱和溶解度及Mn-Fe-C熔体的热力学性质

根据不同温度下Ｃ在纯Ｆｅ和纯Ｍｎ熔体中的饱和溶解度数据,分别得到Ｃ的饱和溶解度与温度的关系式,利用两个关系式可以直接计算Ｆｅ－Ｃ－Ｍｎ和Ｍｎ－Ｃ－Ｆｅ三元熔体组元的热力学性质,同利用Ｃ在这两种熔体中的饱和溶解度实验数据计算出的熔体组元的热力学性质非常接近。     

Fe-C-V三元系熔体中碳与钒的活度相互作用系数

在六孔石墨坩埚中测得1350～1500℃范围内Fe-C-V熔体中碳溶解度为 X_c=0.083+6.57×10_(-5)T—(0.484—5.6×10_(-4)T)X_v由此算出钒对碳的活度相互作用系数是用三元系Gibbs-Duhem方程式求出碳对钒的活度相互作用系数是这些数据符合Lupis和Elliott的倒易关系。     

稀土元素在铁液中热力学参数的研究

本文用稀土元素对碳饱和溶解度法研究Fe-C_(饱和)-RE三元熔体平衡,得到1300～1500℃范围内稀土与碳的相互作用系数与温度的关系:e_(Ce)~C=-9158/T 4.578;e_(La)~C=-8207/T 3.907;e_(Nd)~C=-5888/T 2.818;e_(Sm)~C=-6250/T 2.801;e_y~C=-6164/T 2.963。用铁液-固体脱硫产物直接平衡法研究Fe-C_(饱和)-RE-S四元熔体在1300～1500℃的平衡,得到稀土元素生成RE_2S_3的脱硫常数与温度的关系(K_(RE)=α_(RE)~2α_S~3):1gK_(Ce)=-70025/T 26.000;IgK_(La)=-66114/T 21.833;1gK_(Nd)=-53026/T 17.020;1gK_(Sm)=-54469/T 15.889。并得到稀土与硫的相互作用系数与温度的关系:e_S~(Ce)=-4094/T 0.077,e_S~(La)=-4831/T 1.021,e_S~(Nd)=-6609/T 1.586,e_S~(Sm)=-6512/T 1.681。依据Fe-RE相图计算了Fe-RE二元熔体中稀土元素和铁的活度,得到γ_(EE)~0、e_(RE)~(RE)和ρ_(RE)~(RE)与温度的关系式。     

Fe-C_(sat)-V,Fe-C_(sat)-Nb三元熔体的热力学

根据Fe-C_(aat)-j三元系中a_c=1的性质,通过实验测定1400℃时j元素对碳溶解度的影响关系,结合已知的各一阶活度相互作用系数εf,求得相应的二阶活度相互作用系数。得到结果如下实验。     

含钡二元合金熔体热力学性质的计算

根据Miedema二元合金生成热模型，结合相关热力学数据，对Si-Ca二元合金熔体在1623K时的组元活度进行了计算，计算结果与实测结果吻合较好。并进一步对Ba-Si、Ba-Al和Ba-Ca3种二元含钡合金熔体的生成热△H及1873K时的过剩熵S^E、过剩自由能G^E以及不同温度下各组元的活度等热力学性质进行了计算。结果表明：3种合金的△H、S^E和G^E均为负值，且S^E绝对值的最大值为4．424J／mol，可以近似认为3种合金熔体的S^E为零；Ba-Si和Ba-Al合金熔体的活度相对于理想溶液存在较大负偏差，而Ba-Ca合金熔体的活度与理想溶液偏差较小。     

Fe C N金属熔体作用浓度计算模型

 实验在MoSi2电阻炉内用饱和浓度法测试了Fe C N体系氮的浓度和活度,并根据含化合物的金属熔体结构的共存理论模型,推导了Fe C N金属熔体作用浓度计算模型。实验测得1 485 ℃碳饱和的Fe C N熔体中在氮分压01 MPa时氮的溶解度为0006 5%,并且计算的作用浓度与相应的实测活度相符合,从而证明所得模型可以反映Fe C N金属熔体的结构本质,由模型得出金属熔体高碳含量有利于脱氮。     

Fe－Bi－j三元溶液体系热力学参数的测定与模型计算

利用气液平衡实验方法和三元系液态合金组元间相互作用系数的计算模型，测定和计算了Ｆｅ－Ｂｉ－ｊ三元溶液体系在１８７３Ｋ时第三组元Ｃｒ，Ｃｕ，Ｃ，Ａｌ和Ｓｉ对Ｂｉ的活度相互作用系数以及ｌｎγ~０值。实验值与模型计算值符合良好。     

锰铁熔体中磷和锰的热力学性质

通过１４００℃下Ｆｅ－Ｍｎ－Ｃ－Ｐ系中碳的溶解平衡实验，测定了该熔体中碳的溶解度，应用热力学理论计算出，，，并提出了适用于锰铁熔体中磷和锰的活度系数计算式     

金属钇在碳饱和铁水中脱硫的热力学研究

用直接法首次研究了1300℃～1500℃碳饱和铁水中[Y]-[S]平衡关系。测得了钇的脱硫常数与温度的关系:lgK_(YS)=-22663/T+ 7.9;得到Fe-C(饱和)体系钇的表观脱硫常数与温度的关系:lgK_(YS)=-3487/T-1.1,硫化钇在碳饱和铁水中标准生成自由能与温度的关系:△G_(YS)=-103680+36.14T(卡/摩尔钇)=-433800+151.21T(焦耳/摩尔钇);得到钇在碳饱和铁水中的溶解自由能与温度的关系:△G_Y(e)→[Y]=18820-21.91T(卡/摩尔钇)=78740-91.67T(焦耳/摩尔钇);得到相互作用系数e_S~Y与温度的关系:e_S~Y=-47072/T+19.5。碳对钇和硫的相互作用系数正负相反影响,随温度升高逐渐减小,在1600℃时接近抵消。本实验为钇用于铁水脱硫提供了有用的热力学数据。     

Thermodynamic Properties of Fe-C-N and Fe-C-B-N Melts

The saturated solubility of carbon and nitrogen in Fe-C-N and Fe-C-B-N melts was measured experimentally at 1 485℃ to obtain the activity interaction coefficients between components in these melts. A new method was used to treat experimental results. Using thermodynamic derivation and calculation, some important interac- tion coefficients between components in these melts were obtained.     

Thermodynamics of Fe-C-j （j=Al, Si, P, S） Melts

Based on a proposed method, the mathematical expressions between carbon solubility in Fe-C-j (j = Al, Si, P, S) melts and temperature were obtained. The expressions show the relation of the affecting factors of component j and temperature on carbon solubility, and the activity interaction coefficient of j upon carbon depends on atomic number, covalent radius and electro-negativity. The affecting factors of four elements on carbon solubility are all negative. There is a linear relationship between covalent radius and electro-negativity.     

Thermodynamic Properties of Mn-C Melts

Carbon solubility in Mn-Fe melts（xMn=0.161-0.706,xFe=0.034-0.633）was measured experimentally at various temperatures.By thermodynamic derivation and calculation,the relationship between activity coefficient of carbon in infinite dilute solution of manganese in Mn-C system and temperature was obtained.Using Gibbs-Duhem relationship,the experimental results of this study,and experimental data reported in references,the relationship between other thermodynamic properties in Mn-C system and temperature were obtained by thermodynamic derivation and calculation.     

Relationship between Thermodynamic Parameters for Mn-Fe Melt and Temperature

The carbon solubility in Mn Fe melts were measured at 1 350℃ , 1 375℃, 1 425℃and 1 450℃, and accordingly the calculated equations were obtained. By thermodynamic derivation and calculation, some relationships between thermodynamic parameters for Mn-Fe melt and temperature were obtained.     

Relationship Between Activity Interaction Parameters in Fe-C System and Temperature

Carbon solubility in Fe-Mn melts (xFe=0.102 3-0. 789 9, xMn=0.055 1-0.638 0) was measured exper-imentally at various temperatures. Using Gibbs-Duhem equation, in combination with the experimental results in this work, quoting experimental data reported in references, and by strict thermodynamic derivation and calculation, the relation equations between the activity interaction parameters in Fe-C system and temperature were obtained. The calculation equation of InγFe> in Fe-C system was also obtained. The calculated results show that these relation equa-tions can be used to calculate the activity coefficients of carbon and iron in Fe-C system and can satisfy the necessary condition to satisfy Gibbs-Duhem equation and the necessary condition to satisfy the stability condition of system at high carbon content. The calculation formula for Inγc in Fe-Mn-C system was also obtained.     

Thermodynamic Properties of Carbon and Manganese in Mn-C and Mn-Fe-C Melts

Carbon solubility in Mn Fe melts （xMn =0. 083-0. 706, XFe =0. 034-0. 715） was measured experimentally at various temperatures. By thermodynamic derivation and calculation, the relationship between activity coefficient of carbon in infinite dilute solution of manganese in Mn-C system and temperature was obtained. Using Gibbs-Duhem relationship, the experimental results of this study, and experimental data obtained by strict thermodynamic derivation and calculation in references, the relationships between other thermodynamic properties （εCC, εCCC, εCFe, εCCFe, and εCFeFe） in Mn-Fe-C system and temperature were obtained.     

Thermodynamics of carbon in liquid manganese and ferromanganese alloys

The thermodynamics of carbon in manganese and ferromanganese melts were studied to predict the refining limit of carbon during the decarburization of molten ferromanganese. The equilibrium carbon content in a Mn-C melt was determined by the C-CO equilibrium in the presence of pure solid MnO at 1673 to 1773 K. The activities of manganese and carbon in the Mn-C melt were then calculated from the experimental results, the equilibrium constant for the reaction, and the Gibbs-Duhem equation integrated by the Belton-Fruehan treatment. The standard free-energy change of carbon dissolution in the manganese melt was determined to be 41,700 — 59.6 T J/g · atom, with the standard state taken as 1 wt pct carbon in solution. The effect of iron on the activity coefficient of carbon in ferromanganese was determined by measuring the carbon solubility in Mn-Fe melts. The first- and second-order interaction parameters between carbon and iron in ferromanganese melts were determined. The activity coefficient of carbon in the ferromanganese alloy melt can be expressed as

Thermodynamic Simulation of the A<Superscript>III</Superscript>–B<Superscript>V</Superscript> Semiconductor Melts

The equilibrium compositions and the thermodynamic characteristics of binary Ga–Sb, Al–Sb, and In–Sb melts are studied by a thermodynamic simulation using the TERRA software package over wide temperature and composition ranges. The temperature dependences of the partial pressures of the components of the gas phase forming above the III–V (III = Ga, In; V = Sb) semiconductor melts are investigated. The concentration dependences of the component activities and the partial and integral characteristics of melt mixing are obtained. All melts under study are shown to exhibit large negative deviations from Raoult’s law, which is caused by the presence of associates and indicates a strong interaction between the melt components. The temperature dependences of the logarithms and the partial pressures of the gas phase components are obtained. These dependences are shown to be linear for the components of the gas phase forming over the Ga–Sb, Al–Sb, and In–Sb melts.