Skip to main content
Log in

Simulation of the growth of austenite during continuous heating in low carbon iron alloys

  • Original Paper
  • Published:
Journal of Materials Science Aims and scope Submit manuscript

Abstract

The growth of austenite from martensite or carbon-supersaturated ferrite matrix during continuous heating, which accompanies carbon diffusion in the growing austenite, was studied by DICTRA and linearized gradient approximation extended to include soft impingement of diffusion fields in the matrix. While the austenite growth is controlled by carbon diffusion in ferrite at an early stage, it is controlled by diffusion in austenite at the intermediate and late stages. At a low heating rate, the austenite-finish temperature Af is almost equal to the Ae3 temperature of the alloy, whereas at a high heating rate, Af exceeds the Ae3 to a progressively larger extent with the increasing heating rate and matrix grain size. At a very high heating rate, i.e., 105–106 °C/s, the mobility of α/γ interface is likely to have a significant influence on the growth of austenite, and the untransformed ferrite matrix is transformed in a massive mode. These results are in accordance with the earlier observation of austenite formation during rapid heating in a low carbon iron alloy.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9
Fig. 10
Fig. 11
Fig. 12

Similar content being viewed by others

References

  1. Takechi H (2008) Transformation hardenability of steel sheet for automotive applications. JOM 60:22–26

    Article  Google Scholar 

  2. Speich GR, Demarest VA, Miller RL (1981) Formation of austenite during intercritical annealing of dual-phase steels. Metall Trans A 12A:1419–1428

    Article  Google Scholar 

  3. Nehrenberg AE (1950) The growth of austenite as related to prior structure. Trans AIME 188:162–188

    Google Scholar 

  4. Zener C (1949) Theory of growth of spherical precipitates from solid solution. J Appl Phys 20:950–953

    Article  Google Scholar 

  5. Hillert M (1975) Diffusion and interface control of reactions in alloys. Metall Trans A 6A:5–19

    Article  Google Scholar 

  6. Hillert M, Höglund L (2006) Mobility of & ∝/γ/phase interfaces in Fe alloys. Scr Mater 54:1259–1263

    Article  Google Scholar 

  7. Gamsjäger E, Militzer M, Fazeli F, Svoboda J, Fisher FD (2006) Interface mobility in case of the austenite-to-ferrite phase transformation. Comput Mater Sci 37:94–100

    Article  Google Scholar 

  8. Enomoto M, Aaronson HI (1980) On the linearized gradient approximation for diffusion-limited growth of a spherical precipitate. J Appl Phys 51:818–819

    Article  Google Scholar 

  9. Jönsson B (1993) Trita-Mac-0514. Royal Institute of Technology, Stockholm 1993

    Google Scholar 

  10. Ågren J (1986) A Revised expression for the diffusivity of carbon in binary Fe-C austenite. Scr Metall. 20:1507–1510

    Article  Google Scholar 

  11. Chen H, Van der Zwaag S (2011) Modeling of soft impingement effect during solid-state partitioning phase transformations in binary alloys. J Mater Sci 46:1328–1336. doi:10.1007/s10853-010-4922-5

    Article  Google Scholar 

  12. Ridley N, Stuart H (1970) Partial molar volumes from high-temperature lattice parameters of iron-carbon austenites. Met Sci. 4:219–222

    Article  Google Scholar 

  13. Sietsma J, Van der Zwaag S (2004) A concise model for mixed-mode phase transformations in the solid state. Acta Mater 52:4143–4152

    Article  Google Scholar 

  14. Faires JD, Burdedn RL (1993) Numerical methods. PWS-KENT, Boston 5

    Google Scholar 

  15. Speich GR, Szirmae A (1969) Formation of austenite from ferrite and ferrite-carbide aggregates. Trans TMS AIME 245:1063–1074

    Google Scholar 

  16. Enomoto M (2002) Simulation of ferrite growth in continuously cooled low-carbon iron alloys. Metall Mater Trans A 33A:2309–2316

    Article  Google Scholar 

  17. Moszner F, Povoden-Karadeniz E, Pogatscher S, Uggowitzer PJ, Estrin Y, Gerstl SSA, Kozeschnik E, Löffler JF (2014) Reverse α′→γ transformation mechanisms of martensitic Fe-Mn and age-hardenable Fe-Mn-Pd alloys upon fast and slow continuous heating. Acta Mater 72:99–109

    Article  Google Scholar 

  18. Wits JJ, Kop TA, Van Leeuwen Y, Sietsma J, Van der Zwaag S (2000) A study on the austenite-to-ferrite phase transformation in binary substitutional iron alloys. Mater Sci Eng A283:234–241

    Article  Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to M. Enomoto.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Enomoto, M., Hayashi, K. Simulation of the growth of austenite during continuous heating in low carbon iron alloys. J Mater Sci 50, 6786–6793 (2015). https://doi.org/10.1007/s10853-015-9234-3

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s10853-015-9234-3

Keywords

Navigation