scholarly journals Interaction parameters of oxygen and deoxidants in liquid iron

2016 ◽  
Vol 52 (1) ◽  
pp. 41-46 ◽  
Author(s):  
e Costa
Keyword(s):  
Liquid Iron ◽  
Atomic Number ◽  
Thermodynamic Modeling ◽  
Calphad Method ◽  
Interaction Parameters ◽  
Heats Of Formation ◽  
Dilute Solution ◽  
Dilute Solutions ◽  
Interaction Coefficients ◽  
Computational Tools

During decades before the evolution of more powerful computational tools, simplified formalisms such as the Wagner dilute solution formalism, have been successfully used in the study of deoxidation reactions of steel. This formalism relies on the introduction of interaction coefficients to account from deviations from Henry?s Law. With the evolution of thermodynamic modeling and of the CALPHAD method, the fact that thermodynamic descriptions using these parameters were derived to be used at relatively dilute solution has been sometimes overlooked and the formalism has been criticized for deviating from reality in non-dilute solutions. In this work, it is shown that the interaction parameters used in this formalism correlate with properties of the solutes and of the solvent. The work focuses on the interactions in systems Fe-M-O, where M is a deoxidant. Correlations between interaction coefficients and heats of formation of the corresponding oxides and with the atomic number of the deoxidants are demonstrated. This not only helps supporting the physicochemical soundness of the formalism but also provides a way of checking the consistency of data presented in this formalism.

Thermodynamic Analysis on the Minimum of Oxygen Content in the Deoxidation Equilibrium Curve in Liquid Iron

2016 ◽  
Vol 35 (4) ◽  
pp. 347-351 ◽  
Author(s):  
Pei-Wei Han ◽  
Pei-Xian Chen ◽  
Shao-Jun Chu
Keyword(s):  
Oxygen Content ◽  
Thermodynamic Analysis ◽  
Liquid Iron ◽  
Second Order ◽  
Interaction Parameters ◽  
Equilibrium Curve ◽  
Interaction Coefficients ◽  
First Order ◽  
Deoxidation Equilibrium ◽  
Special Case

AbstractThe minimum of oxygen content in the deoxidation equilibrium in liquid iron was thermodynamically analyzed in the present paper. Two criteria were developed to determine the existence of the minimum. The first criterion was $$0 \le x\gamma _{\rm{M}}^{\rm{M}} + y\gamma _{\rm{O}}^{\rm{M}} \le \min ({x \mathord{\left/{\vphantom {x {4.606[\% {\rm{M}}]_{{\rm{ex}}}^2}}} \right.\kern-\nulldelimiterspace} {4.606[\% {\rm{M}}]_{{\rm{ex}}}^2}},{{{{(xe_{\rm{M}}^{\rm{M}} + ye_{\rm{O}}^{\rm{M}})}^2}} \mathord{\left/{\vphantom {{{{(xe_{\rm{M}}^{\rm{M}} + ye_{\rm{O}}^{\rm{M}})}^2}} {3.474x}}} \right.\kern-\nulldelimiterspace} {3.474x}})$$ with $$xe_{\rm{M}}^{\rm{M}} + ye_{\rm{O}}^{\rm{M}} \lt 0$$, or $$x\gamma _{\rm{M}}^{\rm{M}} + y\gamma _{\rm{O}}^{\rm{M}}{\rm{\lt 0}}$$. And the second criterion was $$(xe_{\rm{M}}^{\rm{O}} + ye_{\rm{O}}^{\rm{O}}) + {y \mathord{\left/{\vphantom {y {2.303{{[\% {\rm{O}}]}_{{\rm{ex}}}}}}} \right.\kern-\nulldelimiterspace} {2.303{{[\% {\rm{O}}]}_{{\rm{ex}}}}}} \gt 0$$. The criteria in terms of first-order activity interaction parameters were the special case of present thermodynamic analysis with neglecting the second-order activity interaction parameters. They were not fit for the case of $$xe_{\rm{M}}^{\rm{M}} + ye_{\rm{O}}^{\rm{M}} \gt 0$$, in which case the criteria in terms of second-order activity interaction parameters should be taken into account to determine the existence of the minimum. The value 0.11 of $$e_{{\rm{Si}}}^{{\rm{Si}}}$$ was smaller based on the existence of the minimum for the Fe-O-Si system. It was guaranteed that the minimum value of oxygen content on the deoxidation equilibrium curve existed at silicon content 20 mass%, when the value 0.32 of $$e_{{\rm{Si}}}^{{\rm{Si}}}$$ was chosen, and the second-order activity interaction coefficients $$\gamma _{{\rm{Si}}}^{{\rm{Si}}}$$ and $$\gamma _{\rm{O}}^{{\rm{Si}}}$$ satisfied the condition $$\gamma _{{\rm{Si}}}^{{\rm{Si}}} + 2\gamma _{\rm{O}}^{{\rm{Si}}} = - 1.54 \times {10^{- 3}}$$.

The use of methyl green as a histochemical reagent

1965 ◽  
Vol s3-106 (73) ◽  
pp. 3-13
Author(s):  
JOHN R. BAKER ◽  
ELIZABETH G. M. WILLIAMS
Keyword(s):  
Connective Tissue ◽  
Malachite Green ◽  
Helix Aspersa ◽  
Common Snail ◽  
Methyl Green ◽  
Dilute Solution ◽  
Dilute Solutions ◽  
The Common ◽  
Snail Helix Aspersa

The cation of methyl green carriea two poaitive charges, that of malachite green only one; but the two dyes behave towards tissue-constituents in almost exactly the same way. These dyes are not specific for chromatin. They colour certain objects that are devoid of DNA, even when they are used in very dilute solution. The granules of cells called Körnchenzellen in the connective tissue of the common snail, Helix aspersa, are strongly coloured by both dyes from very dilute solutions, and thus provide a striking instance of the unspecificity of these dyes. Malachite green, which is stable and free from contamination by metachromstic impurities, can advantageously replace the methyl green commonly used in mixtures with pyronine. It is suggested that pyronine may have a greater capacity for penetrating into close-textured objects, such ss nucleoli and ribosomes, than methyl and malachite greens.

Volume-related interaction parameters for dilute solutions of 1,3-dimethylpropyleneurea in normal and heavy water between 278.15K and 318.15K

2011 ◽  
Vol 513 (1-2) ◽  
pp. 26-32 ◽  
Author(s):  
Evgeniy V. Ivanov ◽  
Elena Yu. Lebedeva ◽  
Vladimir K. Abrosimov
Keyword(s):  
Heavy Water ◽  
Interaction Parameters ◽  
Dilute Solutions

Thermodynamic activity of antimony at dilute solutions in carbon-saturated liquid iron

1993 ◽  
Vol 24 (6) ◽  
pp. 963-973 ◽  
Author(s):  
C. L. Nassaralla ◽  
E. T. Turkdogan
Keyword(s):  
Liquid Iron ◽  
Thermodynamic Activity ◽  
Saturated Liquid ◽  
Dilute Solutions

Thermodynamics of Aluminum Deoxidization Equilibria in GCr18Mo Bearing-Steel

2018 ◽  
Vol 382 ◽  
pp. 80-85 ◽  
Author(s):  
Xin Su ◽  
Shu Qiang Guo ◽  
Meng Ran Qiao ◽  
Hong Yan Zheng ◽  
Li Bin Qin
Keyword(s):  
Bearing Steel ◽  
Second Order ◽  
The Other ◽  
Interaction Parameters ◽  
Interaction Coefficients ◽  
Concentration Region ◽  
Order Interaction ◽  
First Order ◽  
The Relationship ◽  
Reaction Equilibrium

Based on the predecessors of thermodynamic data, the relationship between aluminum contents and oxygen contents of the aluminum deoxidization reaction was calculated. And the influence of activity coefficient to the reaction equilibrium in bearing-steel is analyzed. First-order and second-order interaction coefficients were used to calculate and draw the equilibrium curves, respectively. The effects of different temperature and different interaction parameters on the deoxidization equilibrium curves were studied. And through the curve the influence of the change of aluminum contents to the activity can be known. The trend of the curve with first-order interaction parameters is consistent with the curve with first-order and second-order interaction parameters at the low Al concentration region. And the oxygen contents of curve with first-order interaction parameters are higher than the other curve at the high Al concentration region

Thermodynamic modeling of Mg–Ca–Ce system by combining first-principles and CALPHAD method

2008 ◽  
Vol 463 (1-2) ◽  
pp. 294-301 ◽  
Author(s):  
Hui Zhang ◽  
Yi Wang ◽  
Shunli Shang ◽  
Long-Qing Chen ◽  
Zi-Kui Liu
Keyword(s):  
Thermodynamic Modeling ◽  
First Principles ◽  
Calphad Method

Evaluation of Wagner Interaction Parameter in Fe-Mn-Si-Nb-Ti-V-C System

2005 ◽  
Vol 475-479 ◽  
pp. 3327-3330 ◽  
Author(s):  
Sang Hwan Lee ◽  
Kyung Sub Lee ◽  
Kyung Jong Lee
Keyword(s):  
Gibbs Energy ◽  
Thermodynamic Model ◽  
Lattice Model ◽  
Excess Gibbs Energy ◽  
Chemical Potential ◽  
Solution Model ◽  
Interaction Parameters ◽  
Dilute Solution ◽  
Relationship Of ◽  
The Relationship

The dilute solution model is quite widely used because the chemical potential is more easily defined than that in the sub-lattice model. In the present study, the thermodynamic model for the Fe-Mn-Si-Nb-Ti-V-C system was conducted by evaluating Wagner interaction parameters. The data used in this work was collected and modified by means of TCFE 2000-database in Thermo-Calc and up-to date references. The relationship of interaction parameters(L) in the sub-lattice model and Wagner interaction parameters in the dilute solution model was derived. The composition dependency of reference state and the higher order interaction parameters of the excess Gibbs energy were considered to evaluate Wagner interaction parameters. The equilibrium compositions of austenite and fractions of phases and the dissolution temperature of precipitates(NbC, VC, and TiC) were evaluated by the dilute solution model and compared with the results by the sub-lattice model.

Dynamics of single polyelectrolyte chains in salt-free dilute solutions investigated by analytical ultracentrifugation

2015 ◽  
Vol 17 (24) ◽  
pp. 15896-15902 ◽  
Author(s):  
Zhonglin Cao ◽  
Sha Wu ◽  
Guangzhao Zhang
Keyword(s):  
Analytical Ultracentrifugation ◽  
Complex Dynamics ◽  
Electrostatic Repulsion ◽  
Dilute Solution ◽  
Dilute Solutions

Two concentration regimes are distinguished in polyelectrolyte salt-free dilute solution. The complex dynamics of polyelectrolytes arises due to the interchain electrostatic repulsion.

scholarly journals Thermodynamic modeling of the In-Sc and In-Y systems supported by first-principles calculations

2018 ◽  
Vol 54 (2) ◽  
pp. 161-167 ◽  
Author(s):  
Z. Hu ◽  
C. Huang ◽  
J. Tu ◽  
Y. Huang ◽  
A. Dong
Keyword(s):  
Intermetallic Compounds ◽  
Thermodynamic Modeling ◽  
First Principles ◽  
Regular Solution Model ◽  
Calphad Method ◽  
Enthalpies Of Formation ◽  
Thermodynamic Optimization ◽  
First Principles Calculations ◽  
Self Consistent ◽  
Good Agreement

Based on an assessment of the phase equilibria and thermodynamic data in the literature, the thermodynamic modeling of the In?Sc and In?Y systems was carried out by means of the calculation of phase diagram (CALPHAD) method supported by first-principles calculations. The solution phases, i.e., liquid, (In), (?Sc), (?Sc), (?Y) and (?Y), were modeled with the substitutional regular solution model. Ten intermetallic compounds, including InSc3, InSc2, In4Sc5, InSc, In2Sc, In3Sc, InY2, InY, In5Y3, and In3Y were described as stoichiometric phases, while In3Y5 was modeled with a sublattice model with respect to its homogeneity range. The enthalpies of formation of the intermetallic compounds at 0 K were computed using firstprinciple calculations and were used as input for the thermodynamic optimization. A set of self-consistent thermodynamic parameters for both the In?Sc and In?Y systems were obtained and the calculated phase diagrams are in good agreement with the experimental data.

scholarly journals Thermodynamic description of the C-Ge and C-Mg systems

2010 ◽  
Vol 46 (1) ◽  
pp. 97-103 ◽  
Author(s):  
B. Hu ◽  
Y. Du ◽  
H. Xu ◽  
W. Sun ◽  
W.W. Zhang ◽  
...  
Keyword(s):  
Thermodynamic Parameters ◽  
Enthalpy Of Formation ◽  
Thermodynamic Modeling ◽  
First Principles ◽  
Thermodynamic Description ◽  
Calphad Method ◽  
Thermodynamic Calculations ◽  
First Principles Calculation ◽  
System A ◽  
The Enthalpy Of Formation

The thermodynamic modeling for the C-Ge and C-Mg systems is performed by the CALPHAD method. The enthalpy of formation for Mg2C3, the experimental value of which is not available in the literature, is obtained via first-principles calculation to refine the thermodynamic modeling of the C-Mg system. A comparison of the thermodynamic calculations with the available literature data shows that the presently obtained two sets of thermodynamic parameters for the C-Ge and C-Mg systems can well describe the these two systems.

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