THERMODYNAMIC ANALYSIS OF THE INTERACTION BETWEEN CHROMIUM AND OXYGEN IN THE LIQUID IRON
DOI:
https://doi.org/10.14529/met190301Keywords:
Fe–Cr–O system, thermodynamic modeling, phase equilibriaAbstract
The study of the possibility of the interaction between chromium and oxygen during the production of chromium-containing steels is one of the practically important tasks for the steelmaking. In the present work, thermodynamic modeling of phase equilibria in the temperature range 1600–1800 °C for the Fe–Cr–O system was carried out. Thermodynamic analysis was performed using the method for constructing of the surface solubility of components in a metal, which is a diagram linking changes in the compositions of the liquid metal with changes in the compositions of the resulting interaction products. For the simulation, we used the data on the equilibrium constants of the reactions occurring in the melt, as well as the values of the first-order interaction parameters (according to Wagner) of the components in the liquid iron. In the course of the work, it was found that, in the temperature range 1600–1800 °C, the following products can be formed as interaction products: liquid oxide nonmetallic inclusions of variable composition (FeO, CrO, Cr2O3); solid particles of the ferrochromite FeCr2O4; pure solid chromium oxide Cr2O3; solid particles of the compound Cr3O4. The boundaries of the thermodynamic stability of these oxide phases formed in the melt of the Fe–Cr–O system were also determined. According to the calculation results, the deoxidizing ability of chromium in an oxygen-containing iron-based melt was evaluated. It is determined that the maximum deoxidizing ability of chromium at 1600 °C falls on the equilibrium region of the liquid metal with the solid chromium oxide Cr2O3, while the minimum oxygen concentration is 0.0204 wt. % for 5.31 wt. % chromium. The results obtained in the course of this calculation were compared with the available literature data.References
Mikhailov G.G., Leonovich B.I., Kuznetsov Yu.S. Termodinamika metallurgicheskikh protsessov i sistem [Thermodynamics of Metallurgical Processes and Systems]. Moscow, MISIS Publ., 2009. 520 p.
Samoilova O.V., Makrovets L.A., Mikhailov G.G. Phase Equilibria in Liquid Metal of the Cu–Al–Cr–O System. Russian Journal of Non-Ferrous Metals, 2017, vol. 58, no. 6, pp. 579–585. DOI: 10.3103/S1067821217060116
Hidayat T., Shishin D., Jak E., Decterov S.A. Thermodynamic Reevaluation of the Fe–O System. Calphad, 2015, vol. 48, pp. 131–144. DOI: 10.1016/j.calphad.2014.12.005
Kubaschewski O., Alcock C.B. Metallurgical Thermochemistry. Oxford, Pergamon Press Ltd Publ., 1979. 392 p.
Degterov S., Pelton A.D. Critical Evaluation and Optimization of the Thermodynamic Properties and Phase Diagrams of the CrO–Cr2O3, CrO–Cr2O3–A12O3, and CrO–Cr2O3–CaO Systems. Journal of Phase Equilibria, 1996, vol. 17, no. 6, pp. 476–487. DOI: 10.1007/BF02665994
Samsonov G.V. Fiziko-khimicheskie svoistva okislov [Physico-Chemical Properties of Oxides]. Moscow, Metallurgiya Publ, 1969. 456 p.
Berezhnoy A.S. Mnogokomponentnye sistemy okislov [Multicomponent Oxide Systems]. Kiev, Naukova dumka, 1970. 544 p.
De Villiers J.P.R., Muan A. Liquidus–Solidus Phase Relations in the System CaO–CrO–Cr2O3–SiO2. Journal of the American Ceramic Society, 1992, vol. 75, no. 6, pp. 1333–1341. DOI: 10.1111/j.1151-2916.1992.tb04191.x
Arnout S., Guo M., Jung I.-H., Blanpain B., Wollants P. Experimental Determination of CaO–CrO–Cr2O3–MgO–SiO2 and Thermodynamic Modeling of the CrO–Cr2O3–MgO–SiO2 System. Journal of the American Ceramic Society, 2009, vol. 92, no. 8, pp. 1831–1839. DOI: 10.1111/j.1551-2916.2009.03115.x
Mikhailov G.G. Termodinamicheskie printsipy optimizatsii protsessov raskisleniya stali i modifitsirovaniya nemetallicheskikh vklyucheniy. Diss. dokt. tekhn. nauk [Thermodynamic Principles of Optimization of the Process of Deoxidizing Steel and Modifying Non-Metallic Inclusions. Dr. sci. diss.]: Vol. 2. Chelyabinsk, 1985. 765 p.
Belov B.F., Novohatskiy I.A., Rusakov L.N., Goroh A.V., Savinskaya A.A. Phase Equilibrium Diagram of the FeO–Cr2O3 System. Journal of Physical Chemistry, 1968, vol. XLII, no. 7, pp. 1635–1637. (in Russ.)
Mikhailov G.G., Chernova L.A. [Phase Equilibria Diagrams in the Metal Melts of the Fe–Si–Cr–Mn–O–C System]. Bulletin of the Pryazovskyi State Technical University, 1999, no. 7, pp. 94–105. (in Russ.)
Belov B.F., Novohatskiy I.A. The Interaction of Liquid Iron with Oxide Melts of Variable Composition (nFeO + mCr2O3) (L). Journal of Physical Chemistry, 1974, vol. XLVIII, no. 11, pp. 2860–2864. (in Russ.)
Kulikov I.S. Raskislenie metallov [Deoxidation of Metals]. Moscow, Metallurgiya Publ., 1975. 504 p.
Steelmaking Data Sourcebook, Japan Society for the Promotion of Science, The 19th Committee on Steelmaking. New York, Gordon and Breach Science Publishers, 1988. 325 p.
Ghosh A., Murthy G.V.R. An Assessment of Thermodynamic Parameters for Deoxidation of Molten Iron by Cr, V, Al, Zr and Ti. Transactions ISIJ, 1986, vol. 26, no. 7, pp. 629–637. DOI: 10.2355/isijinternational1966.26.629
Chipman J. Atomic Interaction in Molten Alloy Steels. Journal of the Iron and Steel Institute, 1955, vol. 180, pp. 97–106.
Itoh T., Nagasaka T., Hino M. Equilibrium between Dissolved Chromium and Oxygen in Liquid High Chromium Alloyed Steel Saturated with Pure Cr2O3. ISIJ International, 2000, vol. 40, no. 11, pp. 1051–1058. DOI: 10.2355/isijinternational.40.1051
Arh B., Tehovnik F. The Oxidation and Reduction of Chromium during the Elaboration of Stainless Steels in an Electric Arc Furnace. Materials and Technology, 2007, vol. 41, no. 5, pp. 203–211.
Samoylova O.V., Makrovets L.A. Thermodynamic Modeling of the Phase Diagrams of Oxide Systems FeO–MgO, FeO–Cr2O3, MgO–Cr2O3 and FeO–MgO–Cr2O3. Bulletin of the South Ural State University. Ser. Metallurgy, 2019, vol. 19, no. 1, pp. 18–25. (in Russ.) DOI: 10.14529/met190102
Wang L.J., Liu Y.Q., Wang Q., Chou K.C. Evolution Mechanisms of MgO·Al2O3 Inclusions by Cerium in Spring Steel Used in Fasteners of High-Speed Railway. ISIJ International, 2015, vol. 55, no. 5, pp. 970–975. DOI: 10.2355/isijinternational.55.970
Sigworth G.K., Elliott J.F. The Thermodynamics of Liquid Dilute Iron Alloys. Metal Science, 1974, vol. 8, pp. 298–310.
Hilty D.C., Forgeng W.D., Folkman R.L. Oxygen Solubility and Oxide Phases in the Fe–Cr–O System. Transactions AIME. Journal of Metals, 1955, vol. 203, pp. 253–268.
Fruehan R.J. Activities in the Liquid Fe–Cr–O System. Transactions of the Metallurgical Society of AIME, 1969, vol. 245, pp. 1215–1218.
Janke D., Fischer W.A. Gleichgewichte von Chrom und Mangan mit Sauerstoff in Eisenschmelzen bei 1600 °C. Archiv für das Eisenhüttenwesen, 1976, vol. 47, no. 3, pp. 147–151.
Jung I.-H., Decterov S.A., Pelton A.D. A Thermodynamic Model for Deoxidation Equilibria in Steel. Metallurgical and Materials Transactions B, 2004, vol. 35B, no. 3, pp. 493–507. DOI: 10.1007/s11663-004-0050-4.
