Metals and Materials International

, Volume 20, Issue 5, pp 807–817 | Cite as

Microstructural and precipitation characterization in Nb-Mo microalloyed steels: Estimation of the contributions to the strength

  • N. Isasti
  • D. Jorge-Badiola
  • M. L. Taheri
  • P. Uranga


The influence of coiling temperature on the final microstructure and precipitation has been analyzed in several low carbon Nb and Nb-Mo microalloyed steels. A throughout characterization of the complex microstructures has been performed using electron backscattered diffraction, measuring low and high angle unit sizes, microstructural substructure, as well as quantifying the homogeneity. An important microstructural refinement is observed for all compositions as the coiling temperature decreases. Regarding precipitation, the coiling temperature strongly modifies the size and density of the fine precipitates, being 550 °C the optimal coiling temperature for the Nb-Mo steels. The addition of Mo to Nb steels provides a refinement of the precipitates and, therefore, enhances their contribution to strengthening. Considering all the microstructural and precipitation quantification data, the yield strength was estimated and the contribution of the different mechanisms calculated. The grain size contribution is proven to be the most important factor regarding strengthening, followed by dislocation density and precipitation especially at low coiling temperatures and Nb-Mo steels.


metals thermomechanical processing precipitation electron backscattering diffraction Nb-Mo microalloyed steels 


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  1. 1.
    S. G. Jansto, Proc. New Developments on Metallurgy and Applications of High Strength Steels Conf., p. 1313, John Wiley & Sons, Inc., Buenos Aires, Argentina (2008).Google Scholar
  2. 2.
    D. Bhattacharya, Proc. 6 th Int. Conf. on High Strength Low Alloy Steels, HSLA’2011, The Chinese Society for Metals, Beijing, China (2011).Google Scholar
  3. 3.
    M. Gómez, L. Rancel, and S. F. Medina, Met. Mater. Int. 15, 689 (2009).CrossRefGoogle Scholar
  4. 4.
    H. Mohrbacher, Proc. Int. Seminar on Applications of Mo in Steels, p. 75 (eds. {ieCISRI and IMOA}), Beijing, China (2010).Google Scholar
  5. 5.
    R. D. K. Misra, H. Nathani, J. E. Hartmann, and F. Siciliano, Mater. Sci. Eng. A, 394, 339 (2005).CrossRefGoogle Scholar
  6. 6.
    M. A. Altuna, A. Iza-Mendia, and I. Gutierrez, La Metallurgia Italiana. pp.41–47 (2009).Google Scholar
  7. 7.
    A. J. DeArdo, Int. Mat. Rev. 48, 371 (2003).CrossRefGoogle Scholar
  8. 8.
    V. Thillou, M. Hua, C. I. Garcia, C. Perdrix, and A. J. DeArdo, Mater. Sci. Forum, 284–286, 311 (1998).CrossRefGoogle Scholar
  9. 9.
    A. Iza-Mendia, M. A. Altuna, B. Pereda, and I. Gutierrez, Met. Mater. Trans. A, 43, 4553 (2012).CrossRefGoogle Scholar
  10. 10.
    W. B. Lee, S. G. Hong, C. G. Park, K. H. Kim, and S. H. Park, Scripta Mater., 43, 319 (2000).CrossRefGoogle Scholar
  11. 11.
    W. B. Lee, S. G. Hong, C. G. Park, and S. H. Park, Met. Mater. Trans. A, 33, 1689 (2002).CrossRefGoogle Scholar
  12. 12.
    N. Isasti, D. Jorge-Badiola, M. L. Taheri, B. López, and P. Uranga, Met. Mater. Trans. A, 42, 3729 (2011).CrossRefGoogle Scholar
  13. 13.
    N. Isasti, B. Pereda, B. López, J.M. Rodriguez-Ibabe, and P. Uranga, Nb and Mo Metallurgy for More Sustainable Steels, (ed. H. Mohrbacher), TMS, Warrendale, USA, (2013). (In press).Google Scholar
  14. 14.
    N. Isasti, D. Jorge-Badiola, M. L. Taheri, and P. Uranga, Met. Mat. Trans. A, 44, 3552 (2013).CrossRefGoogle Scholar
  15. 15.
    A. Iza-Mendia and I. Gutiérrez, Mater. Sci. Eng. A, 561, 40 (2013).CrossRefGoogle Scholar
  16. 16.
    M. J. Merwin, C. T. Becker, and D. R. Giansante, Proc. MS&T’09 Conf., p. 956, (eds. {ieACerS, AIST, ASM, TMS}), Pittsburgh, USA (2009).Google Scholar
  17. 17.
    P. Cizek, B. P. Wynne, C. H. J. Davies, B. C. Muddle, and P. D. Hodgson, Met. Mater. Trans. A, 33, 1331 (2002).CrossRefGoogle Scholar
  18. 18.
    D. N. Hanlon, J. Sietsma, and S. van der Zwaag, ISIJ Int. 41, 1028 (2001).CrossRefGoogle Scholar
  19. 19.
    Y. van Leeuwen and J. Sietsma, Mater. Sci. Forum, 539–543, 4572 (2007).CrossRefGoogle Scholar
  20. 20.
    M. Olasolo, P. Uranga, J.M. Rodriguez-Ibabe, and B. López, Mater. Sci. Eng. A, 528, 2559, (2011).CrossRefGoogle Scholar
  21. 21.
    P. Uranga, A. I. Fernández, B. López, and J. M. Rodriguez-Ibabe, Proc. 43 rd Mechanical Working and Steel Processing Conf., p. 511, ISS, Warrendale, USA (2001).Google Scholar
  22. 22.
    N. Isasti, Ph. D. Thesis, University of Navarra, Donostia-San Sebastian, Spain (2013).Google Scholar
  23. 23.
    S. Vervynckt, P. Thibaux, and K. Verbeken, Met. Mater. Int. 18, 37 (2012).CrossRefGoogle Scholar
  24. 24.
    H. Wada and R. D. Pehlke, Met. Trans. B, 16, 815 (1985).CrossRefGoogle Scholar
  25. 25.
    M. G. Akben, B. Bacroix, and J. J. Jonas, Acta Met. 31, 161 (1983).CrossRefGoogle Scholar
  26. 26.
    F. B. Pickering, Physical Metallurgy and the Design of Steels, p. 10, Applied Science Publishers, London, UK (1978).Google Scholar
  27. 27.
    I. A. Yakubtsov, J. D. Boyd, W. J. Liu, and E. Essadiqui, Proc. 42 nd Mechanical Working and Steel Processing Conf., p. 429, ISS, Warrendale, USA (2000).Google Scholar
  28. 28.
    J. Lu, D. Ivey and H. Henein, Iron & Steel Technol. 10, 232 (2013).Google Scholar
  29. 29.
    F. B. Pickering and T. Gladman, Metallurgical Developments in Carbon Steels, Special Report No. 81, Iron and Steel Institute, London, UK (1963).Google Scholar
  30. 30.
    M. Calcagnotto, D. Ponge, E. Demir, and D. Raabe, Mater. Sci. Eng. A, 527, 2738, (2010).CrossRefGoogle Scholar
  31. 31.
    L. P. Kubin and A. Mortensen, Scripta Mater. 48, 119 (2003).CrossRefGoogle Scholar
  32. 32.
    T. Gladman, Mater. Sci. Technol. 15, 30 (1999).CrossRefGoogle Scholar
  33. 33.
    M. F. Ashby and R. Ebeling, AIME Met. Soc. Trans. 236, 1396 (1966).Google Scholar
  34. 34.
    K. Poorhaydari and D. G. Ivey, Can. Met. Quart. 48, 115 (2009).CrossRefGoogle Scholar
  35. 35.
    M. E. Bush and P. M. Kelly, Acta Met. 19, 1363 (1971).CrossRefGoogle Scholar

Copyright information

© The Korean Institute of Metals and Materials and Springer Science+Business Media Dordrecht 2014

Authors and Affiliations

  • N. Isasti
    • 1
  • D. Jorge-Badiola
    • 1
  • M. L. Taheri
    • 2
  • P. Uranga
    • 1
  1. 1.CEIT and TECNUN (University of Navarra)Donostia-San Sebastian, Basque CountrySpain
  2. 2.Department of Materials ScienceDrexel UniversityPhiladelphiaUSA

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