Metallurgical and Materials Transactions A

, Volume 47, Issue 5, pp 1984–1995 | Cite as

Atom Probe Tomography Study of Multi-microalloyed Carbide and Carbo-Nitride Precipitates and the Precipitation Sequence in Nb-Ti HSLA Steels

  • Monica Kapoor
  • Ronald O’Malley
  • Gregory B. Thompson


Composition analysis of carbide and carbo-nitride precipitates was performed for two Nb-Ti microalloyed steels with yield strengths of 750 and 580 MPa using an atom probe study. In the high-Ti 750 MPa steel, Ti-rich (Ti,Nb)(C,N) and Ti-rich (Ti,Nb)(C) precipitates were observed. In the high-Nb 580 MPa steel, a Ti-rich (Ti,Nb)(C,N) precipitate and (Ti,Nb)(C) clusters were noted. These (Ti,Nb)(C) clusters in the high-Nb 580 MPa steel were smaller than the (Ti,Nb)(C) precipitates in high-Ti 750 MPa steel. In general, a larger number of precipitates were found in the high-Ti 750 MPa steel. This difference in the number density of the precipitates between the two steels is attributed to the difference in Ti content. Combining the atom probe tomography results and thermodynamic calculations, the precipitation sequence in these alloys was inferred to be the following: as the temperature decreases, TiN precipitates out of the solution with successive (Ti,Nb)(C,N) layers of varying composition forming on these Ti-rich precipitates. Once N is depleted from the solution, a second set of (Ti,Nb)(C) precipitates in a similar manner in the matrix and also onto the carbo-nitride phase. This observation is consistent with previous observations in high-strength low-alloy steels containing comparable amounts of only Nb. It was noted that the amount of Nb, Nb/(Nb + Ti), in the precipitates decreased from 0.20 to 0.04 with the size of the precipitate. We believe that this is due to the Nb supersaturation in the matrix when these precipitates nucleate.


Atom Probe Large Precipitate Atom Probe Tomography Small Precipitate Precipitation Sequence 
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.



The authors would like to acknowledge the Alabama Innovation Grant for their support. UA’s Central Analytical Facility operated under the Office for Sponsored Research is also acknowledged. Ms. Suzanne Kornegay and Mr. Tyler Kaub are acknowledged for their assistance in obtaining STEM–HAADF images and XRD scans, respectively.

Supplementary material

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Supplementary material 1 (TIFF 1521 kb)
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Supplementary material 2 (TIFF 1522 kb)
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Supplementary material 3 (TIFF 1521 kb)
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Supplementary material 4 (DOCX 10 kb)


  1. 1.
    T. Gladman: The Physical Metallurgy of Microalloyed Steels, Maney, London, 2002.Google Scholar
  2. 2.
    M.P. Rao, V.S. Sarma, S. Sankaran, Materials Science and Engineering: A, 568 (2013) 171-175.CrossRefGoogle Scholar
  3. 3.
    M. Charleux, W.J. Poole, M. Militzer, A. Deschamps, Metallurgical and Materials Transactions A, 32A (2001) 1635-1647.CrossRefGoogle Scholar
  4. 4.
    E. Pereloma, I. Timokhina, K. Russell, M. Miller, Scripta Materialia, 54 (2006) 471-476.CrossRefGoogle Scholar
  5. 5.
    I.B. Timokhina, P.D. Hodgson, S.P. Ringer, R.K. Zheng, E.V. Pereloma, Scripta Materialia, 56 (2007) 601-604.CrossRefGoogle Scholar
  6. 6.
    H.-W. Yen, P.-Y. Chen, C.-Y. Huang, J.-R. Yang, Acta Materialia, 59 (2011) 6264-6274.CrossRefGoogle Scholar
  7. 7.
    R. Misra, K. Tenneti, G. Weatherly, G. Tither, Metallurgical and Materials Transactions A, 34 (2003) 2341-2351.CrossRefGoogle Scholar
  8. 8.
    A. Ruiz-Aparicio. Evolution of Microstructure in Nb-Bearing Microalloyed Steels Produced by the Compact Strip Production Process. Masters Thesis, Material Science and Engineering University of Pittsburgh, 2004, pp. 154.Google Scholar
  9. 9.
    S. Shanmugam, M. Tanniru, R.D.K. Misra, D. Panda, S. Jansto, Materials Science and Technology, 21 (2005) 883-892.CrossRefGoogle Scholar
  10. 10.
    M. Tanniru, S. Shanmugam, R.D.K. Misra, D. Panda, S. Jansto, Materials Science and Technology, 21 (2005) 159-164.CrossRefGoogle Scholar
  11. 11.
    S. Shanmugam, M. Tanniru, R. Misra, D. Panda, S. Jansto, Materials science and technology, 21 (2005) 165-177.CrossRefGoogle Scholar
  12. 12.
    C.P. Reip, S. Shanmugam, R.D.K. Misra, Materials Science and Engineering: A, 424 (2006) 307-317.CrossRefGoogle Scholar
  13. 13.
    Z. Jia, R.D.K. Misra, R. O’Malley, S.J. Jansto, Materials Science and Engineering: A, 528 (2011) 7077-7083.CrossRefGoogle Scholar
  14. 14.
    Y. Li, D.N. Crowther, P.S. Mitchell, T.N. Baker, ISIJ International, 42 (2002) 636-644.CrossRefGoogle Scholar
  15. 15.
    R. Wang, C.I. Garcia, M. Hua, K. Cho, H. Zhang, A.J. DeArdo, ISIJ International, 46 (2006) 1345-1353.CrossRefGoogle Scholar
  16. 16.
    Y. Li, J.A. Wison, D.N. Crowther, P.S. Mitchell, A.J. Craven, T.N. Baker, ISIJ International, 44 (2004) 1093-1102.CrossRefGoogle Scholar
  17. 17.
    K.Y. Xie, L. Yao, C. Zhu, J.M. Cairney, C.R. Killmore, F.J. Barbaro, J.G. Williams, S.P. Ringer, Metallurgical and Materials Transactions A, 42 (2011) 2199-2206.CrossRefGoogle Scholar
  18. 18.
    P.J. Felfer, C.R. Killmore, J.G. Williams, K.R. Carpenter, S.P. Ringer, J.M. Cairney, Acta Materialia, 60 (2012) 5049-5055.CrossRefGoogle Scholar
  19. 19.
    T. Baker, Y. Li, J. Wilson, A. Craven, D. Crowther, Materials Science and Technology, 20 (2004) 720-730.CrossRefGoogle Scholar
  20. 20.
    R.D.K. Misra, H. Nathani, J.E. Hartmann, F. Siciliano, Materials Science and Engineering: A, 394 (2005) 339-352.CrossRefGoogle Scholar
  21. 21.
    M. Perez, E. Courtois, D. Acevedo, T. Epicier, P. Maugis, Philosophical Magazine Letters, 87 (2007) 645-656.CrossRefGoogle Scholar
  22. 22.
    Y. Chen, G. Tang, H. Tian, L. Feipeng, Y. Zhang, L. Wang, Z. Deng, D. Luo, Journal of Materials Science and Technology, 22 (2006) 759-762.CrossRefGoogle Scholar
  23. 23.
    A. Craven, K. He, L. Garvie, T. Baker, Acta Materialia, 48 (2000) 3857-3868.CrossRefGoogle Scholar
  24. 24.
    A. Craven, K. He, L. Garvie, T. Baker, Acta materialia, 48 (2000) 3869-3878.CrossRefGoogle Scholar
  25. 25.
    C.M. Enloe, K.O. Findley, C.M. Parish, M.K. Miller, B.C. De Cooman, J.G. Speer, Scripta Materialia, 68 (2013) 55-58.CrossRefGoogle Scholar
  26. 26.
    F. Danoix, E. Bémont, P. Maugis, D. Blavette, Advanced Engineering Materials, 8 (2006) 1202-1205.CrossRefGoogle Scholar
  27. 27.
    E. Bémont, E. Cadel, P. Maugis, D. Blavette, Surface and Interface Analysis, 36 (2004) 585-588.CrossRefGoogle Scholar
  28. 28.
    S. Mukherjee, I.B. Timokhina, C. Zhu, S.P. Ringer, P.D. Hodgson, Acta Materialia, 61 (2013) 2521-2530.CrossRefGoogle Scholar
  29. 29.
    J. Angseryd, F. Liu, H.O. Andren, S.S. Gerstl, M. Thuvander, Ultramicroscopy, 111 (2011) 609-614.CrossRefGoogle Scholar
  30. 30.
    O.C. Hellman, J.A. Vandenbroucke, J. Rusing, D. Isheim, D.N. Seidman, Microscopy and Microanalysis, 6 (2000) 437-444.Google Scholar
  31. 31.
    M.K. Miller: Atom Probe Tomography: Analysis at the Atomic Level, Springer, New York, 2012.Google Scholar
  32. 32.
    A.J. Breen, K.Y. Xie, M.P. Moody, B. Gault, H.-W. Yen, C.C. Wong, J.M. Cairney, S.P. Ringer, Microscopy and Microanalysis, 20 (2014) 1100-1110.CrossRefGoogle Scholar
  33. 33.
    B. Gault, F. Danoix, K. Hoummada, D. Mangelinck, H. Leitner, Ultramicroscopy, 113 (2012) 182-191.CrossRefGoogle Scholar
  34. 34.
    M. Kapoor, D. Isheim, G. Ghosh, S. Vaynman, M.E. Fine, Y.-W. Chung, Acta Materialia, 73 (2014) 56-74.CrossRefGoogle Scholar
  35. 35.
    M.D. Mulholland, D.N. Seidman, Acta Materialia, 59 (2011) 1881-1897.CrossRefGoogle Scholar
  36. 36.
    J.J. Irani, R.W.K. Honeycombe, Journal of Iron and Steel Institute, 203 (1965) 826-833.Google Scholar
  37. 37.
    D. Raynor, Whiteman J.A., R.W.K. Honeycombe, Journal of Iron and Steel Institute, 204 (1966) 349-354.Google Scholar
  38. 38.
    D.H. Jack, K.H. Jack, Materials Science and Engineering, 11 (1973) 1-27.CrossRefGoogle Scholar
  39. 39.
    J.H. Jang, C.-H. Lee, Y.-U. Heo, D.-W. Suh, Acta Materialia, 60 (2012) 208-217.CrossRefGoogle Scholar
  40. 40.
    W.-B. Lee, S.-G. Hong, C.-G. Park, S.-H. Park, Metallurgical and materials transactions A, 33A (2002) 1689-1698.CrossRefGoogle Scholar
  41. 41.
    K.Y. Xie, T. Zheng, J.M. Cairney, H. Kaul, J.G. Williams, F.J. Barbaro, C.R. Killmore, S.P. Ringer, Scripta Materialia, 66 (2012) 710-713.CrossRefGoogle Scholar
  42. 42.
    F. Vurpillot, A. Bostel, D. Blavette, Applied Physics Letters, 76 (2000) 3127-3129.CrossRefGoogle Scholar

Copyright information

© The Minerals, Metals & Materials Society and ASM International 2016

Authors and Affiliations

  • Monica Kapoor
    • 1
    • 4
  • Ronald O’Malley
    • 2
    • 3
  • Gregory B. Thompson
    • 1
  1. 1.Department of Metallurgical and Materials EngineeringThe University of AlabamaTuscaloosaUSA
  2. 2.Nucor Steel Decatur, LLCTrinityUSA
  3. 3.PSMRC Materials Science & EngineeringMissouri S&TRollaUSA
  4. 4.National Energy Technology LaboratoryAlbanyUSA

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