Effect of molybdenum and chromium on hardenability of low-carbon boron-added steels

  • Futao Han
  • Byoungchul HwangEmail author
  • Dong-Woo Suh
  • Zuocheng Wang
  • Duk Lak Lee
  • Sung-Joon Kim


The hardenability of low-carbon boron-added steels containing molybdenum or chromium was studied using dilatometry, thermodynamic calculations, and secondary ion mass spectroscopy (SIMS). The combined addition of boron and molybdenum was found to be more effective than that of boron and chromium in enhancing the hardenability of boron-added steels. In particular, the addition of 0.5 wt.% molybdenum to the boron-added steel almost completely suppressed the formation of polygonal ferrite even at a slow cooling rate of 0.5°C/s. The synergistic effect of the combined addition of molybdenum and boron is thought to be due to both the suppression of M23(C,B)6 precipitation resulting from the deterioration of phase stability and the reduction of carbon diffusivity by the molybdenum addition.


hardenability molybdenum chromium boron-added steel 


  1. 1.
    Ph. Maitrepierre, D. Thivellier, and R. Tricot,Metall. Trans. A 6, 287 (1975).CrossRefGoogle Scholar
  2. 2.
    D. McLean,Grain Boundaries in Metals, Clarendon Press, Oxford (1957).Google Scholar
  3. 3.
    D. V. Doane and J. S. Kirkaldy,Hardenability Concepts with Application to Steel, AIME, Warrendale, PA (1978).Google Scholar
  4. 4.
    S. K. Banerji and J. E. Morral,Proc. Int. Symp. Boron in Steels, TMS-AIME, Warrendale, PA (1979).Google Scholar
  5. 5.
    D. H. Werner,Boron and Boron Containing Steels, Stahleisen, Germany (1995).Google Scholar
  6. 6.
    Front of Research on Behavior of Boron in Steels, ISIJ, Tokyo (2003).Google Scholar
  7. 7.
    Y.-S. Choi, S.-J. Kim, I.-M. Park, K.-W. Kwon, and I.-S. Yoo,Met. Mater.-Int. 3, 118 (1997).Google Scholar
  8. 8.
    D.-H. Seo, N.-H. Heo, and H.-C. Lee,Met. Mater.-Int. 3, 118 (1997).Google Scholar
  9. 9.
    R. A. Grange and J. B. Mitchell,Trans. Am. Soc. Met. 53, 157 (1961).Google Scholar
  10. 10.
    G. F. Melloy, P. R. Slimmon, and P. P. Podgursky,Metall. Trans. 4, 2279 (1973).CrossRefGoogle Scholar
  11. 11.
    M. Ueno and K. Itoh,Tetsu-to-Hagane 74, 1073 (1988).Google Scholar
  12. 12.
    L. Karlsson and H. Norden,Acta metall. 36, 35 (1988).CrossRefGoogle Scholar
  13. 13.
    X. L. He, Y. Y. Chu, and J. J. Jonas,Acta metall. 37, 147 (1989).CrossRefGoogle Scholar
  14. 14.
    K. A. Taylor,Metall. Trans. A 23, 107 (1992).CrossRefGoogle Scholar
  15. 15.
    H. Asahi,ISIJ Int. 42, 1150 (2002).CrossRefADSGoogle Scholar
  16. 16.
    Atlas for Bainitic Microstructures, Vol. 1, ISIJ, Tokyo (1992).Google Scholar
  17. 17.
    S.-J. Lee, M. T. Lusk, and Y.-K. Lee,Acta mater. 55, 875 (2007).CrossRefGoogle Scholar
  18. 18.
    ASTM A255-02 Standard Test Method for Determining Hardenability of Steel (2002).Google Scholar
  19. 19.
    P. Cizek, B. P. Wynne, C. H. J. Davies, B. C. Muddle, and P. D. Hodgson,Metall. Trans. A 33, 1331 (2002).CrossRefGoogle Scholar
  20. 20.
    T. Hara, H. Asahi, R. Uemoro, and H. Tamehiro,ISIJ Int. 44, 1431 (2004).CrossRefGoogle Scholar
  21. 21.
    X. Tingdong and S. Shenhua,Acta metall. 37, 2499 (1989).CrossRefGoogle Scholar
  22. 22.
    B.-J. Lee,Private communication, POSTECH (2007).Google Scholar

Copyright information

© Springer 2008

Authors and Affiliations

  • Futao Han
    • 1
    • 2
  • Byoungchul Hwang
    • 1
    Email author
  • Dong-Woo Suh
    • 1
  • Zuocheng Wang
    • 2
  • Duk Lak Lee
    • 3
  • Sung-Joon Kim
    • 1
  1. 1.Department of Advanced Metallic MaterialsKorea Institute of Materials ScienceChangwon, GyeongnamKorea
  2. 2.School of Materials Science and EngineeringShandong UniversityJinanChina
  3. 3.Wire and Rod Research Group, Technical Research LaboratoriesPOSCOPohang, GyeongbukKorea

Personalised recommendations