The Dilatometric and Thermomagnetic Analysis of Tempering Process of Quenched Fe-N Alloys

  • Ignacy Wierszyllowski
  • Leszek Maldzinski
  • Marek Hrebeniak


The majority of published studies concerning tempering of quenched Fe-N alloys were performed by means of the TEM and X-ray methods1–6, In addition, microhardness5–7 and resistivity5 were also studied, Incomplete thermomagnetic investigations were presented in two papers8 and one can find fragmentary dilatometric investigations in a few other papers7,8. Considerations concerning thermal effects accompanying the tempering of quenched Fe-N alloys were presented in one paper7. On the basis of previous studies, the tempering process of quenched Fe-N alloys can be described in the following way:
  • In the first stage of tempering till about 200°C the tetragonal ordered α” (Fe16N2) phase precipitates2,5,6. Precipitation of α” can appear as early as after one week tempering at room temperature7,9. Simultaneously, the content of nitrogen in the matrix decreases. Most authors call the tempered matrix ferrite2,5,6. The precipitation is accompanied by a significant thermal effect7.

  • In the next stage of tempering, which begins at temperatures slightly lower than 200°C, a” progressively disappears and is replaced progressively by γ’ (Fe4N)2,5,6. During this stage of tempering the hardness suddenly decreases7. In dilatometric diagrams significant contraction is visible7,8, thermal effects are small7, and magnetic effects are difficult to interpret unambiguously8. In the case of the presence of residual austenite (RA) after quenching, its transformation begins at a tempering temperature of the order of 230°C2,8. The RA transformation is connected with an increase of magnetization8 and with liberation of heat.7


Magnetic Force Residual Austenite Retain Austenite Isochronal Tempering Iron Nitride 
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.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    K.H. Jack “The iron-nitrogen system: the preparation and the crystal structures of nitrogen-austenite and nitrogen-martensite” Proc. Roy. Soc. A/208, 1951.Google Scholar
  2. 2.
    K.H. Jack “The occurance and the crystal structure of “-iron nitride; a new type of interstitial alloy formed during the tempering of nitrogen martensite”, Proc. Roy. Soc. A/208 1951, p. 216–224.Google Scholar
  3. 3.
    M.G. A. Biswas and I. Codd “An electron transmission study of iron-nitrogen martensite” Journal of The Iron and Steel Institute, 1968, p. 494–497.Google Scholar
  4. 4.
    T.Bell and W.S. Owen “Martensite in iron-nitrogen alloys” Journal of The Iron and Steel Institute, 1967, p. 428–434.Google Scholar
  5. 5.
    T. Bell and D. Brough “The Tempering of Iron-Nitrogen Massive Martensite” Metal Science Journal, 1970, Vol. 4, p. 171–177.CrossRefGoogle Scholar
  6. 6.
    R.D. Garwood and G. Thomas “The Tempering of Martensite in an Fe-1.5 pct. N. Alloy” Metallurgical Transactions.Google Scholar
  7. 7.
    E.I. Mittemeijer, M. Van Rooyen, I. Wierszyllowskl, H.C.F. Rozendaal and P.F. Colijn “Tempering of Iron-Nitrogen Marten-site” Zeitschrift für Metallkunde Bd. 74, 1983, H7, p. 473–483.Google Scholar
  8. 8.
    M.W. Belous, W.T. Czerepin and M.A. Wasiliew “Prevraszczenia pri otpuskie stali” Metallurgija 1973, Moskva, p. 91–100.Google Scholar
  9. 9.
    L. Maldzinski, I. Wierszyllowskl and J. Putniewicz “Production of homogenous martensitic Fe-N alloys” (in Polish) Inzynieria Materialowa, No. 3 (26), 1985, p. 82–86.Google Scholar
  10. 10.
    I. Wierszyllowskl, L. Maldzinski and M. Hrebeniak “Efekty dylatometryczne i magnetyczne podczas odpuszczania stopow Fe-N”. Materialy konferencyjne “Wegliki, Azotki, Borki” Poznan-Kolobrzeg 1984, p. 68–79.Google Scholar
  11. 11.
    I. Wierszyllowskl and J. Jakubowski “The Influence of Transformation Progress on Activation Energy Changes During Low-Temperature Tempering of Quenched Steel” Scripta Metallurgica 20, 1986, p. 49–54.CrossRefGoogle Scholar
  12. 12.
    C.S. Roberts, B.L. Averbach and M. Cohen “The Mechanism and Kinetics of the First Stage of Tempering” Transactions American Society for Metals, Vol. 45, 1953, p. 576.Google Scholar
  13. 13.
    B.A. Fuller and R.D. Garwood “Initial Tempering of Iron-Manganese-Nitrogen Mattensite” Metal Science 1975, Vol. 9, p. 213–216.CrossRefGoogle Scholar
  14. 14.
    M.A. Krishtal “Diffusion Processes in Iron Alloys” (in Russian), Metallurgizdat. 1963, Moskva.Google Scholar
  15. 15.
    H. Schmalzried “Solid State Reactions” Verlag Chemie, GmbH, Weinheim/Berystr. 1974, p. 162.Google Scholar
  16. 16.
    K.M. Vedula and R.W. Heckel “Spheroidization of Binaary Fe-C Alloys over a Range of Temperatures” Metallurgical Transactions 1970, p. 9–18.Google Scholar

Copyright information

© Plenum Press, New York 1987

Authors and Affiliations

  • Ignacy Wierszyllowski
    • 1
  • Leszek Maldzinski
    • 1
  • Marek Hrebeniak
    • 1
  1. 1.Institute of MetallurgyPoznan Technical UniversityPoznanPoland

Personalised recommendations