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Metallurgical Transactions A

, Volume 20, Issue 4, pp 689–697 | Cite as

Nucleation kinetics of Ti carbonitride in microalloyed austenite

  • W. J. Liu
  • J. J. Jonas
Transformations

Abstract

Ti(CN) precipitation data determined by stress relaxation are analyzed using the classical theory of diffusion controlled nucleation. For this purpose, the interface energy γ and strain energy ΔG ɛ accompanying nucleus formation are estimated using a new approach, and the driving force for Ti(CN) nucleation is calculated with the aid of a thermodynamic model. The analysis indicates that the critical nucleus is richer in N than the bulk precipitate at equilibrium at a given holding temperature. The results also show that trace amounts of nitrogen dissolved in austenite can significantly increase the chemical driving force for Ti(CN) nucleation and thereby accelerate the rate of precipitation. On the basis of this analysis, a kinetic model is developed for predicting start times (P S) for the strain-induced precipitation of Ti(CN) in austenite. Such predictions are in reasonably good agreement with measuredP S times.

Keywords

Austenite Metallurgical Transaction Critical Nucleus Bulk Precipitate Classical Nucleation Theory 
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.

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References

  1. 1.
    W.J. Liu and J.J. Jonas:Metall. Trans. A, 1988, vol. 19A, pp. 1415–24.Google Scholar
  2. 2.
    W. Kesternich:Phil. Mag., 1985, vol. 52, pp. 533–48.CrossRefGoogle Scholar
  3. 3.
    I. Weiss and J.J. Jonas:Metall. Trans. A, 1980, vol. 11A, pp. 403–10.Google Scholar
  4. 4.
    N.K. Balliger and R.W.K. Honeycombe:Met. Sci., 1980, vol. 14, pp. 121–33.Google Scholar
  5. 5.
    T. Chandra, I. Weiss, and J.J. Jonas:Can. Metall. Quarterly, 1981, vol. 20, pp. 421–28.Google Scholar
  6. 6.
    T. Chandra, I. Weiss, and J.J. Jonas:Met. Sci., 1982, vol. 16, pp. 97–104.CrossRefGoogle Scholar
  7. 7.
    T. Thorvaldsson and G.L. Dunlop:Met. Sci., 1982, vol. 16, pp. 184–90.Google Scholar
  8. 8.
    O.E. Atasoy:Metall. Trans. A, 1983, vol. 14A, pp. 379–98.Google Scholar
  9. 9.
    J. Strid and K.E. Easterling:Acta Metall., 1985, vol. 33, pp. 2057–74.CrossRefGoogle Scholar
  10. 10.
    B. Dutta and C.M. Sellars:Mater. Sci. Technol., 1987, vol. 3, pp. 197–206.Google Scholar
  11. 11.
    W.J. Liu and J.J. Jonas:Metall. Trans. A, 1988, vol. 19A, pp. 1403–13.Google Scholar
  12. 12.
    K.C. Russell:Advances in Colloid and Interface Science, 1980, vol. 13, pp. 205–318.CrossRefGoogle Scholar
  13. 13.
    K.C. Russell:Scripta Metall 1969, vol. 3, pp. 313–36.CrossRefGoogle Scholar
  14. 14.
    H.I. Aaronson and J.K. Lee,Lectures on the Theory of Phase Transformations, H.I. Aaronson, ed. TMS-AIME, New York, NY, 1982, pp. 83–115.Google Scholar
  15. 15.
    W.J. Liu and J.J. Jonas:Mater. Sci. Technol., 1988, vol. 5, pp. 8–12.Google Scholar
  16. 16.
    L.E. Toth:Transition Metal Carbides and Nitrides, Academic Press, New York and London, 1971.Google Scholar
  17. 17.
    W.J. Liu and J.J. Jonas: McGill University, Montreal, Canada, unpublished research, 1988.Google Scholar
  18. 18.
    H.I. Aaronson, K.R. Kinsman, and K.C. Russell:Scripta Metall., 1970, vol. 4, pp. 101–06.CrossRefGoogle Scholar
  19. 19.
    H. Moll and E. Ogilvie:Trans. TMS-AIME 1959, vol. 215, pp. 613–18.Google Scholar
  20. 20.
    W.J. Liu: Ph.D. Thesis, McGill University, Montreal, Canada, 1987.Google Scholar

Copyright information

© The Metallurgical of Society of AIME 1989

Authors and Affiliations

  • W. J. Liu
    • 1
  • J. J. Jonas
    • 1
  1. 1.Department of Metallurgical EngineeringMcGill UniversityMontrealCanada

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