Metal Science and Heat Treatment

, Volume 21, Issue 2, pp 104–109 | Cite as

Mechanism of grain boundary strengthening of steels

  • M. I. Gol'dshtein
  • B. M. Bronfin
  • A. Z. Shifman
  • V. V. Osipov
Theory

Conclusions

  1. 1.

    The mechanism of grain boundary strengthening depends on several factors, above all the grain size and the condition of the grain boundaries.

     
  2. 2.

    In fine-grained steels the effect of the barrier mechanism of grain boundary strengthening is negligible, while the effect of grain boundaries on resistance to deformation described by the Hall—Petch equation is manifest indirectly through the effect of strain hardening with a more rapid increase of dislocation density.

     
  3. 3.

    With decreasing relative length of grain boundaries (large grains) or enrichment of grain boundaries in impurities and precipitates of second phase the number of potential dislocation sources near grain boundaries decreases. In this case the fulfillment of the Hall—Petch relationship indicates the barrier mechanism of grain boundary strengthening.

     
  4. 4.

    The barrier effect of cell boundaries is evident in austenitic steels with large deformations, which leads to deviation of σf=f(d−1/2) from linear.

     

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Literature cited

  1. 1.
    R. W. Honeycomb, Plastic Deformation of Metals, St. Martin (1968).Google Scholar
  2. 2.
    R. Armstrong et al., Phil. Mag.,7, No. 73, 45 (1962).Google Scholar
  3. 3.
    H. Conrad, "Model of strain hardening to explain the effect of grain size on the flow stress of metals," in: Ultrafine Grains in Metals [Russian translation], Metallurgiya, Moscow (1973), p. 206.Google Scholar
  4. 4.
    M. Holzmann and J. Man, J. Iron Steel Inst.,204, 230 (1966).Google Scholar
  5. 5.
    J. Evans and R. Rawlings, J. Met. Sci.,2, 221 (1968).Google Scholar
  6. 6.
    D. Blucher, D. Grozner, and D. Enrietto, "Strength and toughness of hot rolled ferritic-pearlitic steels," in: Fracture [Russian translation], Vol. 6, Mir, Moscow (1976), p. 246.Google Scholar
  7. 7.
    K. Irvin, T. Gladman, and F. Pickering, J. Iron Steel Inst.,207, 1017 (1969).Google Scholar
  8. 8.
    M. Marienkowski and R. Fisher, Trans. Met. Soc. AIME,233, 293 (1965).Google Scholar
  9. 9.
    D. March, Phil. Mag.,21, 95 (1970).Google Scholar
  10. 10.
    D. Michel, J. Moteff, and A. Lovell, Acta Met.,21, 1269 (1973).Google Scholar
  11. 11.
    A. A. Popov and V. M. Farber, "Effect of deformation on the fine structure of austenitic steels with carbide hardening," Izv. Vyssh. Uchebn. Zaved., Metall. No. 10, 107 (1975).Google Scholar
  12. 12.
    E. V. Belik et al., "Structural changes and brittleness of molybdenum during deformation," Fiz. Met. Metalloved.,24, 535 (1967).Google Scholar
  13. 13.
    L. K. Gordienko, Substructural Hardening of Metals and Alloys [in Russian], Nauka, Moscow (1973).Google Scholar
  14. 14.
    M. I. Gol'dshtein et al., "Precipitation hardening of austenitic steel with vanadium," Fiz. Met. Metalloved.,41, 165 (1976).Google Scholar

Copyright information

© Plenum Publishing Corporation 1979

Authors and Affiliations

  • M. I. Gol'dshtein
  • B. M. Bronfin
  • A. Z. Shifman
  • V. V. Osipov

There are no affiliations available

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