Metallurgical and Materials Transactions B

, Volume 43, Issue 4, pp 830–840 | Cite as

Calcium Modification of Spinel Inclusions in Aluminum-Killed Steel: Reaction Steps

  • Neerav Verma
  • Petrus C. PistoriusEmail author
  • Richard J. Fruehan
  • Michael S. Potter
  • Helmut G. Oltmann
  • Eugene B. Pretorius


Calcium treatment is a well-established way to modify solid alumina inclusions to liquid or partially liquid calcium aluminates. Spinels (Al2O3·xMgO) can also form in liquid steel after aluminum deoxidation. Like alumina, the spinels can be modified readily to liquid inclusions by a calcium treatment. The modification of spinels was studied by observing the transient evolution of inclusions, in laboratory and industrial heats. Spinel modification involves the preferential reduction of MgO from the spinel, with Mg dissolving in the steel, and it proceeds through transient calcium sulfide formation, just like in the case of alumina inclusions. Because magnesium dissolves in steel after the calcium treatment of spinels, the reoxidation of the melt will produce new spinels.


Liquefaction Liquid Steel Magnesium Content Calcium Aluminate Oxide Inclusion 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.



Support of this work by the industrial members of the Center for Iron and Steelmaking Research (CISR) is acknowledged gratefully.


  1. 1.
    K.C. Ahlborg: Fifth Int. Conf. on Clean Steel, OMBKE, Budapest, Hungary, 1997, pp. 151–56.Google Scholar
  2. 2.
    S.R. Story, S.M. Smith, R.J. Fruehan, G.S. Casuccio, M.S. Potter, and T.L. Lersch: Iron Steel Technol., 2005, vol. 2 (9), pp. 41–49.Google Scholar
  3. 3.
    E.B. Pretorius, H.G. Oltmann, and T. Cash: Iron Steel Technol., 2010, vol. 7, no. 7, pp. 31–44.Google Scholar
  4. 4.
    S.R. Story, F.J. Mannion, G.S. Casuccio, and M.S. Potter: Proc. of the Richard J. Fruehan Symposium, Physical Chemistry of Sustainable Metals, AIST, Pittsburgh, PA, 2011, pp. 403–22.Google Scholar
  5. 5.
    N. Verma, M. Lind, P.C. Pistorius, and R.J. Fruehan: Iron Steel Technol., 2010, vol. 7, no. 7, pp. 189–97.Google Scholar
  6. 6.
    P.C. Pistorius, P. Presoly, and K.G. Tshilombo: Sohn Int. Symp., Advanced Process. of Metals and Materials, vol. 2, TMS, Warrendale, PA, 2006, pp. 373–78.Google Scholar
  7. 7.
    S. Yang, J. Li, Z. Wang, J. Li, and L. Lin: Int. J. Miner., Metall. Mater., 2011, vol. 18, pp. 18–23.CrossRefGoogle Scholar
  8. 8.
    N. Verma, P.C. Pistorius, R.J. Fruehan, M. Potter, M. Lind, and S. Story: Metall. Mater. Trans. B, 2011, vol. 42B, pp. 711–19.CrossRefGoogle Scholar
  9. 9.
    P.C. Pistorius and N. Verma: Microsc. Microanal., 2011, vol. 17, pp. 963–71.CrossRefGoogle Scholar
  10. 10.
    C.W. Bale, P. Chartrand, S.A. Degterov, G. Eriksson, K. Hack, R. Ben Mahfoud, J. Melançon, A.D. Pelton, and S. Petersen: CALPHAD: Comput. Coupling Phase Diagrams Thermochem., 2002, vol. 26, pp. 189–228.Google Scholar
  11. 11.
    N. Bannenberg: Steelmaking Conf. Proc., 1995, vol. 78, pp. 457–63.Google Scholar
  12. 12.
    Y. Kang, F. Li, K. Morita, and D. Sichen: Steel Res. Int., 2006, vol. 77, pp. 785–92.Google Scholar
  13. 13.
    N. Verma, P.C. Pistorius, R.J. Fruehan, M. Lind, H. Oltmann, E. Pretorius, and M. Potter: AISTech 2011 Conf. Proc., vol. II, Association for Iron & Steel Technology, Warrendale, PA, 2011, pp. 607–15.Google Scholar
  14. 14.
    J. Gran and D. Sichen: Metall. Mater. Trans. B, 2011, vol. 42B, pp. 921–24.CrossRefGoogle Scholar
  15. 15.
    P. Lorenzino, C. Capurro, C. Cicutti, P. Lardizabal, G. Torga, and F. Fuhr: 17 th IAS Steelmaking Conf., Campana, Buenos Aires, Argentina, 2009, pp. 223–32.Google Scholar
  16. 16.
    N. Verma, P.C. Pistorius, R.J. Fruehan, M. Potter, M. Lind, and S. Story: Metall. Mater. Trans. B, 2011, vol. 42B, pp. 720–29.CrossRefGoogle Scholar
  17. 17.
    S.R. Story, T.J. Piccone, R.J. Fruehan, and M.S. Potter: Iron Steel Technol., 2004, vol. 1, no. 9, pp. 163–69.Google Scholar
  18. 18.
    F. Schamber: Introduction to Automated Particle Analysis by Focused Electron Beam,, 2011.
  19. 19.
    N. Verma, P.C. Pistorius, R.J. Fruehan, and M. Lind: AISTech 2011 Proc., Vol. II, Association for Iron & Steel Technology, Warrendale, PA, 2011, pp. 627–34.Google Scholar
  20. 20.
    F. Salvat, J.A. Escuder, D. Bote, and X. Llovet: Microsc. Microanal., 2007, vol. 13, pp. 1388–89.CrossRefGoogle Scholar
  21. 21.
    J.T. Armstrong and P.R. Buseck: Anal. Chem., 1975, vol. 47, pp. 2178–92.CrossRefGoogle Scholar

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Authors and Affiliations

  • Neerav Verma
    • 1
    • 2
  • Petrus C. Pistorius
    • 1
    Email author
  • Richard J. Fruehan
    • 1
  • Michael S. Potter
    • 3
  • Helmut G. Oltmann
    • 4
  • Eugene B. Pretorius
    • 5
  1. 1.Department of Materials Science and EngineeringCenter for Iron and Steelmaking Research (CISR), Carnegie Mellon UniversityPittsburghUSA
  2. 2.ExxonMobil Upstream Research CompanyHoustonUSA
  3. 3.RJ Lee GroupMonroevilleUSA
  4. 4.Nucor SteelMount PleasantUSA
  5. 5.Steelmaking TechnologyNucor SteelMount PleasantUSA

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