Influence of Manganese Content and Finish Rolling Temperature on the Martensitic Transformation of Ultrahigh-Strength Strip Steels

  • Antti Kaijalainen
  • Mahesh SomaniEmail author
  • Mikko Hemmilä
  • Tommi Liimatainen
  • David A. Porter
  • Jukka Kömi
Conference paper
Part of the The Minerals, Metals & Materials Series book series (MMMS)


The effects of manganese content and finish rolling temperature (FRT) on the transformed microstructures and properties of two low-alloyed thermomechanically rolled and direct-quenched (TM-DQ) steels were investigated. The materials were characterized in respect of microstructures and tensile properties. In addition, microhardness measurements were made both at the surface and centerline of the hot-rolled strips to help characterize the phase constituents. Detailed microstructural features were further revealed by laser scanning confocal microscopy (LSCM) and field emission scanning electron microscopy combined with electron backscatter diffraction (FESEM-EBSD). It was apparent that a decrease in the temperature of controlled rolling, i.e., the finish rolling temperature (FRT), resulted in reduced martensite fractions at the surface, as a consequence of strain-induced fine ferrite formation. The centerline of the strip, however, comprised essentially martensite and upper bainite. In contrast, high FRT and higher manganese content resulted in essentially a fully martensitic microstructure due to enhanced hardenability. The paper presents a detailed account of the hot rolling and hardenability aspects of TM-DQ ultra-high-strength strip steels and corresponding microstructures and properties.


Direct quenching Hardenability Microstructure Prior austenite morphology Ultrahigh-strength 



This work was performed as a part of the Breakthrough Steels and Applications program of DIMECC Oy (the Digital, Internet, Materials & Engineering Co-Creation), Finland. The financial support of the Finnish Funding Agency for Technology and Innovation (Tekes) is gratefully acknowledged.


  1. 1.
    Suikkanen PP, Kömi JI (2014) Mater Sci Forum 783–786:246CrossRefGoogle Scholar
  2. 2.
    Kaijalainen AJ, Suikkanen P, Karjalainen LP, Jonas JJ (2014) Metall Mater Trans A 45:1273CrossRefGoogle Scholar
  3. 3.
    Kaijalainen AJ, Suikkanen PP, Limnell TJ, Karjalainen LP, Kömi JI, Porter DA (2013) J Alloys Compd 577:S642CrossRefGoogle Scholar
  4. 4.
    Asahi H, Tsuru E, Hara T, Sugiyama M, Terada Y, Shinada H, Ohkita S, Morimoto H, Doi N, Murata M, Miyazaki H, Yamashita E, Yoshida T, Ayukawa N, Akasaki H, Macia ML, Petersen CW, Koo JY, Bangaru NV, Luton MJ (2004) Int J Offshore Polar Eng 14:36Google Scholar
  5. 5.
    Hemmilä M, Laitinen R, Liimatainen T, Porter DA (2005) Proceedings of 1st international conference on “Super-High Strength Steels”. Associazone Italiana di Metallurgica – AIM, RomeGoogle Scholar
  6. 6.
    Kaijalainen AJ, Suikkanen PP, Karjalainen LP, Porter DA (2016) Mater Sci Eng A 654:151CrossRefGoogle Scholar
  7. 7.
    Kozasu I (1997) In: Chandra T, Sakai T (eds) International conference on thermomechanical processing of steel and other materials. The Minerals, Metals & Materials Society, Wollongong, pp 47–55Google Scholar
  8. 8.
    Steven W, Haynes AG (1956) J Iron Steel Inst 183:349Google Scholar
  9. 9.
    Pickering FB (1977) In: Korchysky M (ed) Microalloying ’75. Union Carbide Corporation, Washington DC, pp 9–31Google Scholar
  10. 10.
    Stuhlmann W (1954) Härterei Tech Mitteilungen 6:31Google Scholar
  11. 11.
    Wang GD, Wang ZD, Qu JB, Jiang ZY, Liu XH (1997) In: Chandra T, Sakai T (eds) International conference on thermomechanical processing of steel and other materials. The Minerals, Metals & Materials Society, Wollongong, pp 717–723Google Scholar
  12. 12.
    Boratto F, Barbosa R, Yue S, Jonas JJ (1988) In: Tamura I (ed) THERMEC-88. Iron and Steel Institute of Japan, Tokyo, pp 383–390Google Scholar
  13. 13.
    Brownrigg A, Curcio P, Boelen R (1975) Metallography 8:529CrossRefGoogle Scholar
  14. 14.
    Higginson RL, Sellars CM (2003) Worked examples in quantitative metallography. Maney, LondonGoogle Scholar
  15. 15.
    Krauss G (2015) Steels—processing, structure, and performance, 2nd edn. ASM International, Materials ParkGoogle Scholar
  16. 16.
    Pyykkönen J, Suikkanen P, Somani MC, Porter DA (2012) Matériaux Tech 100:S1Google Scholar
  17. 17.
    Kaijalainen AJ, Liimatainen M, Kesti V, Heikkala J, Liimatainen T, Porter DA (2016) Metall Mater Trans A 47:4175CrossRefGoogle Scholar

Copyright information

© The Minerals, Metals & Materials Society 2018

Authors and Affiliations

  • Antti Kaijalainen
    • 1
  • Mahesh Somani
    • 1
    Email author
  • Mikko Hemmilä
    • 2
  • Tommi Liimatainen
    • 2
  • David A. Porter
    • 1
  • Jukka Kömi
    • 1
  1. 1.Materials and Production EngineeringUniversity of OuluOuluFinland
  2. 2.SSAB Europe OyRaaheFinland

Personalised recommendations