Skip to main content
SpringerLink
Log in

Zn Diffusion and α-Fe(Zn) Layer Growth During Annealing of Zn-Coated B Steel

  • Published:
Metallurgical and Materials Transactions A Aims and scope Submit manuscript

Abstract

Direct hot press forming of Zn-coated 22MnB5 steels is impeded by micro-cracks that occur in the substrate due to the presence of Zn during the forming process. A study was therefore undertaken to quantify concentration of Zn across the α-Fe(Zn) coating and on grain boundaries in the α-Fe(Zn) layer and the underlying γ-Fe(Zn) substrate after isothermal annealing of Zn-coated 22MnB5 at 1173 K (900 °C) and to link the Zn distribution to the amount and type of micro-cracks observed in deformed samples. Finite difference model was developed to describe Zn diffusion and the growth of the α-Fe(Zn) layer. The penetration of Zn into the γ-Fe(Zn) substrate after 600 seconds annealing at 1173 K (900 °C) through bulk diffusion is estimated to be 3 μm, and the diffusion depth of Zn on the γ-Fe(Zn) grain boundaries is estimated to be 6 μm, which is significantly shorter than the maximum length (15 to 50 μm) of the micro-cracks formed in the severely stressed conditions, indicating that the Zn diffusion into the γ-Fe(Zn) from the α-Fe(Zn) during annealing is not correlated to the depth of micro-cracks. On the other hand, the maximum amount of Zn present in α-Fe(Zn) layer decreases with annealing time as the layer grows and Zn oxidizes, and the amount of Zn-enriched areas inside the α-Fe(Zn) layer is reduced leading to reduced length of cracking. Solid-Metal-Induced Embrittlement mechanism is proposed to explain the benefit of extended annealing on reduced depth of micro-crack penetration into the γ-Fe(Zn) substrate.

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

Access this article

Log in via an institution

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. European Automotive Research Partners Association R&D technology Roadmap, http://www.earpa.eu/docs/2005/furore_road_map_final.pdf

  2. T Altan, Update: Hot-stamping boron-alloyed steels for automotive parts, Stamping Journal, March/April, (2011)

    Google Scholar 

  3. S. Kim, I. Son, D. Kim, and S. Kim: 4th Int. Conf. on Hot Sheet Met. Forming of UHSS, Lulea, 2013.

  4. P. Drillet, R. Grigorieva, G. Leuillier, and T. Vietoris: Study of Cracks Propagation Inside the Steel on Press Hardened Steel Zinc Based Coatings, 2011, Galvatech, Genova

  5. M.J. van Genderen, W. Verloop, J. Loiseaux, and G. Hensen: 3rd Int. Conf. on Hot Sheet Met. Forming of UHSS, Kassel, 2011

  6. C.W. Lee, D.W. Fan, I.R. Sohn, S.J. Lee, and B.C. De Cooman: Metall. Mater. Trans. A, 2012, vol. 43, 5122-5127

    Article  Google Scholar 

  7. L Cho, H Kang, C Lee, BC De Cooman, Scripta Mater 90-91 (2014) 25-28.

    Article  Google Scholar 

  8. T. Kurz, G. Luckeneder, T. Manzenreiter, and H. Schwinghammer: Zinc Coated Press-Hardening Steel—Challenges and Solutions, SAE Technical Paper 2015-01-0565, 2015

  9. G. Hensen, W. Melfo, and S.P. Chen: 4th Int. Conf. on Hot Sheet Met. Forming of UHSS, Lulea, 2013.

  10. A.R. Marder: Prog. Mater. Sci., 2000, vol. 45, pp. 199–271.

    Article  Google Scholar 

  11. R Autengruber, G Luckeneder, S Kolnberger, J Faderl, A W Hassel, Steel Research Int 83 (2012) 1005–11

    Article  Google Scholar 

  12. V. Janik, P. Beentjes, D. Norman, G. Hensen, and S. Seetharaman: Proceedings of MST2014 Conference, Pittsburgh, 2014, p. 299

  13. I Richter, M Feller-Kniepmeier, Phys. Status Solidi (A) 68 (1981) 289–300.

    Article  Google Scholar 

  14. E.A. Brandes and G.B. Brook, eds.: Smithells Metals Reference Book, 7th ed., Butterworth & Heinemann, Oxford, 1992.

  15. JS Dohie, JR Cahoon, WF Caley, JPEDAV 28 (2007) 322-327.

    Article  Google Scholar 

  16. P. Heitjans and J. Karger, eds., Diffusion in Condensed Matter: Methods, Materials, Models, 2nd ed., Birkhauser, Boston, 2005.

  17. RTP Whipple, Philos Mag 45 (1954) 1225.

    Article  Google Scholar 

  18. H. Schwinghammer, G. Luckenender, T. Manzenreiter, M. Rosner, P. Tsipouridis, and T. Kurz: 4th Int. Conf. on Hot Sheet Met. Forming of UHSS, Lulea, 2013.

  19. SP Lynch, Mat Sci Eng A108 (1989) 203-212

    Article  Google Scholar 

  20. SP Lynch, Mat Characterization 28 (1992) 279-289.

    Article  Google Scholar 

  21. P. Gordon: Metall. Trans., 1978, vol. 9A, pp. 267–273

    Article  Google Scholar 

  22. S.P. Lynch: Acta Metall., 1988, vol. 36, pp. 2639–61

    Article  Google Scholar 

  23. S.P. Lynch: in Environment Induced Cracking of Materials, S. Shipilov, R. Jones, J.-M. Olive, and R. Rebak, eds., Elsevier, Amsterdam, 2007, pp. 167–177.

  24. S.P. Lynch: Metall. Trans., 2013, vol. 44A, 1209–29.

    Article  Google Scholar 

Download references

Acknowledgments

The financial assistance from the WMG Centre High Value Manufacturing Catapult with focus on low C mobility and Tata Steel is gratefully acknowledged. The authors are thankful for the assistance from Dr. Richard Beanland and Steven Hindmarsh at MAS, University of Warwick with the TEM analysis with FIB lift-out. The authors also wish to thank Dr Didier Farrugia for discussing aspects of the diffusion modeling.

Author information

Authors and Affiliations

  1. WMG, University of Warwick, Coventry, CV4 7AL, UK

    Vit Janik (Research Fellow) & Seetharaman Sridhar (Professor)

  2. Swinden Technology Centre, Tata Steel, R&D, Moorgate Road, Rotherham, S60 3AR, UK

    Yongjun Lan (Principal Researcher)

  3. IJmuiden Technology Centre, Tata Steel, R&D, 1970 CA, Ijmuiden, The Netherlands

    Peter Beentjes (Principal Researcher) & Guido Hensen (Principal Researcher)

  4. Automotive Engineering Group, Tata Steel, R&D, Coventry, CV4 7AL, UK

    David Norman (Principal Researcher)

Authors
  1. Vit Janik
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Yongjun Lan
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Peter Beentjes
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. David Norman
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. Guido Hensen
    View author publications

    You can also search for this author in PubMed Google Scholar

  6. Seetharaman Sridhar
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Vit Janik.

Additional information

Manuscript submitted December 11, 2014.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Janik, V., Lan, Y., Beentjes, P. et al. Zn Diffusion and α-Fe(Zn) Layer Growth During Annealing of Zn-Coated B Steel. Metall Mater Trans A 47, 400–411 (2016). https://doi.org/10.1007/s11661-015-3203-y

Download citation

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s11661-015-3203-y

Keywords

Search

Navigation