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Journal of Materials Science

, Volume 29, Issue 10, pp 2605–2610 | Cite as

Effect of bainitic transformation on microstructure of Si-Mn steel

  • Yoshiyuki Tomita
Papers

Abstract

Several Si-Mn steels with similar Si and Mn levels and carbon contents, ranging from 0.25 to 0.75 wt %, were studied to determine the effect of bainitic transformation on the microstructure of Si-Mn steel. The microstructure was categorized by optical metallography, scanning and transmission electron microscopy, and X-ray diffraction. The results showed the existence of an optimum transformation time to produce the maximum content of retained austenite, though the retention of a large amount of retained austenite was encouraged as a result of bainitic transformation. The microstructure consisted of carbon-free upper bainite whose individual ferrite was separated by the ‘thin-film’ type of retained austenite, while the ‘blocky’ type of austenite was also found. The results also showed that carbide precipitation occurred in the residual austenite after the optimum time, which decreased the retained austenite content. The retained austenite stability is discussed in relation to the carbon content and morphology of the retained austenite.

Keywords

Microstructure Transmission Electron Microscopy Carbide Ferrite Austenite 
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.

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References

  1. 1.
    S. J. Matas and R. F. Hehemann, Trans. AIME 221 (1961) 179.Google Scholar
  2. 2.
    H. K. D. H. Bhadeshia and D. V. Edmonds, Metall. Trans. 10A (1979) 895.CrossRefGoogle Scholar
  3. 3.
    Idem, Acta Metall. 28 (1980) 1265.CrossRefGoogle Scholar
  4. 4.
    B. P. J. Sandvic, Metall. Trans. 13A (1982) 777.CrossRefGoogle Scholar
  5. 5.
    H. K. D. H. Bhadeshia and D. V. Edmonds, Met. Sci. 17 (1983) 411.CrossRefGoogle Scholar
  6. 6.
    Idem, ibid., 17 (1983) 420.CrossRefGoogle Scholar
  7. 7.
    V. T. T. Miihkinen and D. V. Edmonds, Mater. Sci. Technol. 3 (1987) 432.CrossRefGoogle Scholar
  8. 8.
    Idem, ibid., 3 (1987) 441.CrossRefGoogle Scholar
  9. 9.
    R. L. Miller, Trans. ASM 61 (1968) 592.Google Scholar
  10. 10.
    N. Ridley, H. Stuart, and L. Zwell, Trans. AIME 245 (1961) 1834.Google Scholar
  11. 11.
    A. J. Baker and P. M. Kelly, in “Electron Microscopy and Strength of Crystals” edited by G. Thomas and J. Washburn (Interscience, New York, London, 1963) p. 899.Google Scholar
  12. 12.
    O. Matumura, Y. Sakuma and H. Takechi, J. Iron Steel Inst. Jpn 77 (1991) 658.Google Scholar
  13. 13.
    S. A. Khan and H. K. D. H. Bhadeshia, Metall. Trans. 21A (1990) 859.CrossRefGoogle Scholar

Copyright information

© Chapman & Hall 1994

Authors and Affiliations

  • Yoshiyuki Tomita
    • 1
  1. 1.Department of Metallurgy and Materials Science, College of EngineeringUniversity of Osaka PrefectureOsakaJapan

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