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Metal Science and Heat Treatment

, Volume 16, Issue 3, pp 210–216 | Cite as

The fine structure of nitrided steels

  • A. V. Gavrilova
  • S. A. Gerasimov
  • G. F. Kosolapov
  • Yu. D. Tyapkin
Fifty Years of Nitriding
  • 29 Downloads

Conclusions

  1. 1.

    The structures formed in the process of nitriding are similar to those observed in aging alloys (Cu−Be and Ni−Be alloys, for example) during decomposition of supersaturated solid solutions.

     
  2. 2.

    It was found that the nitride phase precipitated in binary Fe−Al, Fe−Cr, and Fe−Mo alloys and steels 40Kh and 38KhMYuA have a B1 structure (NaCl type).

     
  3. 3.

    The high strength of the nitrided case on steel 38KhMYuA is due to a considerable extent to distortion of the matrix (α phase) resulting from the formation of finely dispersed nitrides completely or partially coherent with the matrix. The maximum hardness is reached in the initial stage of nitride formation when then thin (single layer of nitrogen atoms) lamellar nuclei are completely coherent with the matrix.

     
  4. 4.

    The high hardness of the nitride case is due mainly to aluminum. The addition of chromium and molybdenum to steel 38KhMYuA makes it possible to obtain (at a sufficiently high nitriding temperature) nitrides with a structure corresponding to the early stages of their formation, which favors a fairly large case depth and high hardness.

     

Keywords

Molybdenum Nitride Nitrogen Atom High Hardness Considerable Extent 
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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Literature cited

  1. 1.
    Yu. M. Lakhtin, Physical Basis of the Nitriding Process [in Russian], Mashgiz, Moscow (1948).Google Scholar
  2. 2.
    A. N. Minkevich, Chemicothermal Treatment of Metals and Alloys [in Russian], Mashinostroenie, Moscow (1965).Google Scholar
  3. 3.
    A. P. Gulyaev, Metal Science [in Russian], Metallurgiya, Moscow (1966).Google Scholar
  4. 4.
    A. V. Gavrilova and Yu. D. Tyapkin, "Change in crystal structure during aging of Ni−Be and Cu−Be alloys," in: Problems of Metal Science and Physics of Metals [in Russian], Moscow (1964), pp. 326–354.Google Scholar
  5. 5.
    G. F. Kosolapov and S. A. Gerasimov, "Structure of α phase in the nitrided case on steels 38KhMYuA and 1Kh13," Metal. i Term. Obrabotka Metal., 5, 71 (1973).Google Scholar

Copyright information

© Consultants Bureau, a division of Plenum Publishing Corporation 1974

Authors and Affiliations

  • A. V. Gavrilova
  • S. A. Gerasimov
  • G. F. Kosolapov
  • Yu. D. Tyapkin

There are no affiliations available

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