Advertisement

Experimental Mechanics

, Volume 59, Issue 8, pp 1145–1157 | Cite as

Mesoscopic Strain Fields Measurement During the Allotropic αγ Transformation in High Purity Iron

  • N. Bruzy
  • M. CoretEmail author
  • B. Huneau
  • G. Kermouche
  • M. Mondon
  • E. Bertrand
  • L. Stainier
Article
  • 71 Downloads

Abstract

The allotropic phase change from ferrite to austenite represents a moment of massive interplay between the microstructural and mechanical states of iron. The difference of compacity between the two phases induces a microplastic accommodation in the material at grain scale. However, mechanical heterogeneities resulting from the transformation process remain challenging to characterise due to the high temperature conditions it is associated with. We developed experimental equipment for in situ observation of αγ and γα transformations. Images of the surface of an iron sample taken by an optical camera were used as input for a Digital Image Correlation (DIC) routine. Special care was taken to maximize image resolution to capture sub-grain phenomena. Observations show that, at the mesoscopic scale, shear strain fields exhibit strong localisations that are evidence of transformations that are occurring.

Keywords

Digital image correlation High temperature Allotropic transformation Pure iron 

Notes

Acknowledgements

This work is part of the SMICE project, which was funded by BPI France under grant P113013-2660682. The authors are extremely grateful to Julien Réthoré for providing access to the UFreckles software and for giving precious advice on how to use it.

References

  1. 1.
    Liu Y, Sommer F, Mittemeijer E (2004) Abnormal austenite-ferrite transformation behaviour of pure iron. Philos Mag 84:18:1853–1876Google Scholar
  2. 2.
    Basinski Z, Hume-Rothery W, Sutton A (1955) The lattice expansion of iron. In: Proceedings of the Royal Society AGoogle Scholar
  3. 3.
    Song S, Liu F, Zhang Z (2014) Analysis of elastic-plastic accomodation due to volume misfit upon solid-state phase transformation. Acta Mater 64:266–281CrossRefGoogle Scholar
  4. 4.
    Zhang X, Komizo Y (2013) In situ investigation of the allotropic transformation in iron. Steel Res Int 84:751–760CrossRefGoogle Scholar
  5. 5.
    Zijlstra G, van Daalen M, Vainchtein D, Ocelik V, Hosson J D (2017) Interphase boundary motion elucidated through in-situ high temperature electron back-scatter diffraction. Mater Des 132:138–147CrossRefGoogle Scholar
  6. 6.
    Leplay P, Réthoré J, Meille S, Baietto M (2012) Identification of asymmetric consitutive laws at high temperature based on digital image correlation. J Eur Ceram Soc 32:3949–3958CrossRefGoogle Scholar
  7. 7.
    Mao W, Chen J, Si M, Zhang R, Ma Q, Fang D, Chen X (2016) High temperature digital image correlation evaluation of in-situ failure mechanism: an experimental framework with application to c/SiC composites. Mater Sci Eng A 665:26–34CrossRefGoogle Scholar
  8. 8.
    Gioacchino FD, da Fonseca JQ (2015) An experimental study of the polycristalline plasticity of austenitic stainless steel. Int J Plast 74:92–109CrossRefGoogle Scholar
  9. 9.
    Guery A, Hild F, Latourte F, Roux S (2016) Slip activities in polycrystals determined by coupling DIC measurements with crystal plasticity calculations. Int J Plast 81:249–266CrossRefGoogle Scholar
  10. 10.
    Bosiers J, Peters I, Draijer C, Theuwissen A (2006) Technical challenges and recent progress in CCD imagers. Nucl Inst Methods Phys Res A 565:148–156CrossRefGoogle Scholar
  11. 11.
    Strangwood M (2012) Phase Transformations in Steels, Woodhead Publishing Limited, chap Fundamentals of ferrite formation in steelsGoogle Scholar
  12. 12.
    Tumbajoy D, Maeder X, Guillonneau G, Sao-Joao S, Descartes S, Bergheau J, Langlade C, Michler J, Kermouche G (2018) Microstructural and micromechanical investigations of surface strengthening mechanisms induced by repeated impacts on pure iron. Mater Des 147:56–64CrossRefGoogle Scholar
  13. 13.
    Bachmann F, Hielscher R, Schaeben H (2011) Grain detection from 2D and 3D EBSD data - specification of the MTex algorithm. Ultramicroscopy 111:1720–1733CrossRefGoogle Scholar
  14. 14.
    Hutchinson W (1989) Recrystallisation textures in iron resulting from nucleation at grain boundaries. Acta metallurgica 37:1047–1056CrossRefGoogle Scholar
  15. 15.
    Zhang Z, Machin G (2009) Experimental Methods in the Physical Sciences, Elsevier, chap Overview of Radiation thermometryGoogle Scholar
  16. 16.
    Lyons J, Liu J, Sutton M (1996) High-temperature deformation measurements using digital image correlation. Meas Sci Technol 36:64–70Google Scholar
  17. 17.
    Grant B, Stone H, Preuss M (2009) High-temperature strain field measurement using Digital Image Correlation. J Strain Anal 44:263–271CrossRefGoogle Scholar
  18. 18.
    Novak M, Zok F (2011) High-temperature materials testing with full-field strain measurement: experimental design and practice. Rev Sci Instrum 82:115101CrossRefGoogle Scholar
  19. 19.
    Dong Y, Kakisawa H, Kagawa Y (2014) Optical system for microscopic observation and strain measurement at high temperature. Meas Sci Technol 25:025002CrossRefGoogle Scholar
  20. 20.
    Pan B, Wu D, Wang Z, Xia Y (2011) High-temperature digital image correlation method for full-field deformation measurement at 1200C. Meas Sci Technol 22:015701CrossRefGoogle Scholar
  21. 21.
    Réthoré J (2018) Ufreckles.  https://doi.org/10.5281/zenodo.1433776
  22. 22.
    Marty J, Réthoré J, Combescure A, Chaudet P (2015) Finite strain kinematics of multi-scale material by digital image correlation. Exp Mech 55:1641–1656CrossRefGoogle Scholar
  23. 23.
    Besnard G, Hild F, Roux S (2006) Finite-element displacement fields analysis from digital images: application to portevin-Le châtelier bands. Exp Mech 46:789–803CrossRefGoogle Scholar
  24. 24.
    Dong Y, Kakisawa H, Kagawa Y (2015) Developement of microscale pattern for digital image correlation up to 1400C. Opt Lasers Eng 68:7–15CrossRefGoogle Scholar
  25. 25.
    Barbe F, Quey R (2011) A numerical modelling of 3D polycrystal-to-polycrystal diffusive phase transformations involving crystal plasticity. Int J Plast 27:823–840CrossRefzbMATHGoogle Scholar
  26. 26.
    Wilkinson A (2000) Electron Backscatterd Diffraction in Materials Science, Springer, chap Measuring strains using electron backscattered diffractionGoogle Scholar
  27. 27.
    Lee J, Shibata K, Asakura K, Masumoto Y (2002) Observation of the αγ transformation in ultralow-carbon steel under a high temperature optical microscope. ISIJ Int 42:1135–1143CrossRefGoogle Scholar

Copyright information

© Society for Experimental Mechanics 2019

Authors and Affiliations

  1. 1.Institut de Recherche en Génie Civil et Mécanique (GeM) UMR6183Ecole Centrale de Nantes, Université de Nantes, CNRSNantesFrance
  2. 2.Laboratoire Georges Friedel (LGF) UMR5307Mines de Saint-Etienne, Université de Lyon, CNRS, Centre SMSSaint-EtienneFrance
  3. 3.Institut des Matériaux Jean Rouxel (IMN) UMR6502Université de Nantes, CNRSNantesFrance

Personalised recommendations