Advanced Thermo-mechanical Process for Homogenous Hierarchical Microstructures in HSLA Steels

  • Carina Ledermueller
  • Ernst Kozeschnik
  • Richard F. Webster
  • Sophie PrimigEmail author


Engineering microstructures in high-strength low-alloy steels via advanced thermo-mechanical processing is a promising approach to overcome challenges around low work hardenability and toughness in ultrafine-grained mild steels. Recently, multiscale-hierarchical microstructures with ultrafine grains and two populations of precipitates decorating high-angle grain boundaries and dislocation structures were achieved by some of the current authors in a modern Ti-Mo-Nb high-strength low-alloy steel. However, the high-strain rate of 10 s−1 during single-pass plane-strain compression at 600 °C led to the formation of macroscopic shear bands. Here, we propose an optimized advanced multi-hit thermo-mechanical process for achieving homogenous hierarchical microstructures in the same steel without strain localization. This is verified via microscopy and thermo-kinetic modelling, using the software MatCalc. A typical body-centred-cubic rolling texture is achieved in contrast to previous process design. Ultrafine crystallites confined by a mixture of high-angle gain and subgrain boundaries are formed, decorated by two types of precipitates. Large FeMnC-rich cementite particles are found on grain boundaries and smaller TiNbC-rich precipitates on dislocations and subgrain boundaries. It is shown that TiNbC particles transform to a core-shell structure when subjected to direct aging. Thermo-kinetic modelling underpins experimental results concerning the detailed evolution of crystallite size, precipitate morphology and composition, enabling a through-process description of the microstructural evolution.



This research has received funding by the Australian Research Council DECRA scheme (Project Number DE180100440, DECRA S. Primig) and by the UNSW Sydney Scientia Fellowship scheme. The authors thank Drs Simon Hager and Charlie Kong for technical assistance and use of facilities supported by Microscopy Australia at the Electron Microscope Unit at UNSW Sydney. Dr David Miskovic’s help with carrying out the Gleeble experiments is gratefully acknowledged. The steel used in this study was supplied by voestalpine Stahl Linz GmbH (Austria).

Author Contributions

CL designed the study, carried out all experiments and modelling except TEM, and drafted the manuscript. RW carried out TEM investigations and related data analyses. EK guided modelling and helped to revise the manuscript. SP supervised CL, helped to design the study, revised the manuscript and wrote parts of it. All authors approved the final version of the manuscript.

Conflict of interest


Data Availability

Date will be made available upon request.


  1. 1.
  2. 2.
    Worldsteel Association: Steel Markets. Accessed 3 August 2019.
  3. 3.
    A.J. DeArdo, M. Hua, K. Cho, and C.I. Garcia: Mater. Sci. Technol., 2009, vol. 25, pp. 1074–82.CrossRefGoogle Scholar
  4. 4.
    S. Vervynckt, K. Verbeken, B. Lopez, and J.J. Jonas: Int. Mater. Rev., 2012, vol. 57, pp. 187–207.CrossRefGoogle Scholar
  5. 5.
    E.O. Hall: Proc. Phys. Soc. Sect. B, 1951, vol. 64, pp. 747–53.CrossRefGoogle Scholar
  6. 6.
    R. Song, D. Ponge, D. Raabe, J.G. Speer, and D.K. Matlock: Mater. Sci. Eng. A, 2006, vol. 441, pp. 1–17.CrossRefGoogle Scholar
  7. 7.
    A. Ohmori, S. Torizuka, and K. Nagai: ISIJ Int., 2004, vol. 44, pp. 1063–71.CrossRefGoogle Scholar
  8. 8.
    Y. Okitsu, N. Takata, and N. Tsuji: Scr. Mater., 2009, vol. 60, pp. 76–9.CrossRefGoogle Scholar
  9. 9.
    B. Eghbali: Mater. Sci. Eng. A, 2010, vol. 527, pp. 3402–6.CrossRefGoogle Scholar
  10. 10.
    L. Cheng, Y. Chen, Q. Cai, W. Yu, G. Han, E. Dong, and X. Li: Mater. Sci. Eng. A, 2017, vol. 698, pp. 117–25.CrossRefGoogle Scholar
  11. 11.
    R. Song, D. Ponge, and D. Raabe: Acta Mater., 2005, vol. 53, pp. 4881–92.CrossRefGoogle Scholar
  12. 12.
    M. Koyama, Z. Zhang, M. Wang, D. Ponge, D. Raabe, K. Tsuzaki, H. Noguchi, and C.C. Tasan: Science, 2017, vol. 355, pp. 1055–57.CrossRefGoogle Scholar
  13. 13.
    Y.M. Wang, T. Voisin, J.T. McKeown, J. Ye, N.P. Calta, Z. Li, Z. Zeng, Y. Zhang, W. Chen, T.T. Roehling, R.T. Ott, M.K. Santala, P.J. Depond, M.J. Matthews, A. V. Hamza, and T. Zhu: Nat. Mater., 2018, vol. 17, pp. 63–70.CrossRefGoogle Scholar
  14. 14.
    R. Song, D. Ponge, and D. Raabe: Scr. Mater., 2005, vol. 52, pp. 1075–80.CrossRefGoogle Scholar
  15. 15.
    C. Ledermueller, H. Li, and S. Primig: Metall. Mater. Trans. A, 2018, vol. 49, pp. 6337–50.CrossRefGoogle Scholar
  16. 16.
    J. Svoboda, F.D. Fischer, P. Fratzl, and E. Kozeschnik: Mater. Sci. Eng. A, 2004, vol. 385, pp. 166–74.Google Scholar
  17. 17.
    E. Kozeschnik, J. Svoboda, P. Fratzl, and F.D. Fischer: Mater. Sci. Eng. A, 2004, vol. 385, pp. 157–65.Google Scholar
  18. 18.
    H. Buken, P. Sherstnev, and E. Kozeschnik: Model. Simul. Mater. Sci. Eng., 2016, vol. 24, p. 35006.CrossRefGoogle Scholar
  19. 19.
    H. Buken and E. Kozeschnik: Metall. Mater. Trans. A, 2017, vol. 48, pp. 2812–8.CrossRefGoogle Scholar
  20. 20.
    E. Kozeschnik: Metall. Mater. Trans. A, 2000, vol. 31A, pp. 1682–4.CrossRefGoogle Scholar
  21. 21.
    E. Kozeschnik, W. Rindler, and B. Buchmayr: Int. J. Mater. Res., 2007, vol. 98, pp. 826–31.CrossRefGoogle Scholar
  22. 22.
    J. Kreyca and E. Kozeschnik: Int. J. Plast., 2018, vol. 103, pp. 67–80.CrossRefGoogle Scholar
  23. 23.
    Y. Xu, J. Zhang, Y. Bai, and M.A. Meyers: Metall. Mater. Trans. A, 2008, vol. 39A, pp. 811–43.CrossRefGoogle Scholar
  24. 24.
    R. Doherty, D.A. Hughes, F.J. Humphreys, J.J. Jonas, D. Juul-Jensen, M.E. Kassner, W.E. King, T.R. McNelley, H.J. McQueen, A.D. Rollett: Mater. Sci. Eng. A, 1997, vol. 238, pp. 219–74.CrossRefGoogle Scholar
  25. 25.
    R.A. Petković, M.J. Luton, and J.J. Jonas: Can. Metall. Q., 1975, vol. 14, pp. 137–45.CrossRefGoogle Scholar
  26. 26.
    T. Furuhara, K. Kobayashi, and T. Maki: ISIJ Int., 2004, vol. 44, pp. 1937–44.CrossRefGoogle Scholar
  27. 27.
    R.A. Grange, C.R. Hribal, and L.F. Porter: Metall. Trans. A, 1977, vol. 8A, pp. 1775–85.CrossRefGoogle Scholar
  28. 28.
    S. Malekjani, I.B. Timokhina, I. Sabirov, and P.D. Hodgson: Can. Metall. Q., 2009, vol. 48, pp. 229–35.CrossRefGoogle Scholar
  29. 29.
    M. Abbasi, A. Kermanpur, A. Najafizadeh, S. Saeedipour, and Y. Mazaheri: Int. J. ISSI, 2012, vol. 9, pp. 6–10.Google Scholar
  30. 30.
    F. Foroozmehr, A. Najafizadeh, and A. Shafyei: Mater. Sci. Eng. A, 2011, vol. 528, pp. 5754–8.CrossRefGoogle Scholar
  31. 31.
    J. Gallego, A.R. Rodrigues, and L. Montanari: Mater. Res., 2014, vol. 17, pp. 527–34.CrossRefGoogle Scholar
  32. 32.
    S. Gourdet and F. Montheillet: Acta Mater., 2003, vol. 51, pp. 2685–99.CrossRefGoogle Scholar
  33. 33.
    J.M. Rosenberg and H.R. Piehler: Metall. Trans., 1971, vol. 2, pp. 257–9.CrossRefGoogle Scholar
  34. 34.
    S.A. Aksenov, Y.A. Puzino, and I.P. Mazur: in Metal, 2015, p. 170–76.Google Scholar
  35. 35.
    S.H.M. Anijdan, M. Hoseini, and S. Yue: Mater. Sci. Eng. A, 2011, vol. 528, pp. 6788–93.CrossRefGoogle Scholar
  36. 36.
    F.T. Han, Z.C. Wang, C.N. Jing, X.M. Liu, J. Su, and S.Y. Zhang: Appl. Mech. Mater., 2013, vol. 331, pp. 443–7.CrossRefGoogle Scholar
  37. 37.
    M.R. Toroghinejad, A.O. Humphreys, D. Liu, F. Ashrafizadeh, A. Najafizadeh, and J.J. Jonas: Metall. Mater. Trans. A, 2003, vol. 34A, pp. 1163–74.CrossRefGoogle Scholar
  38. 38.
    M.R. Barnett and J.J. Jonas: ISIJ Int., 1997, vol. 37, pp. 706–14.CrossRefGoogle Scholar
  39. 39.
    A.O. Humphreys, D. Liu, M.R. Toroghinejad, and J.J. Jonas: ISIJ Int., 2002, vol. 42, pp. S52–6.CrossRefGoogle Scholar
  40. 40.
    Z. Jia, R.D.K. Misra, R. O’Malley, and S.J. Jansto: Mater. Sci. Eng. A, 2011, vol. 528, pp. 7077–83.CrossRefGoogle Scholar
  41. 41.
    M. Kapoor, R. O’Malley, and G.B. Thompson: Metall. Mater. Trans. A, 2016, vol. 47A, pp. 1984–95.CrossRefGoogle Scholar

Copyright information

© The Minerals, Metals & Materials Society and ASM International 2019

Authors and Affiliations

  • Carina Ledermueller
    • 1
  • Ernst Kozeschnik
    • 2
  • Richard F. Webster
    • 3
  • Sophie Primig
    • 1
    Email author
  1. 1.School of Materials Science & EngineeringUNSW SydneySydneyAustralia
  2. 2.Institute of Materials Science and TechnologyTU WienViennaAustria
  3. 3.Electron Microscopy Unit, Mark Wainwright Analytical CentreUNSW SydneySydneyAustralia

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