Rationalisation of austenite transformation to upper or lower bainite in steels

• Autorzy: Ławrynowicz Z.

Identyfikatory

DOI

10.2478/adms-2014-0006

• Języki publikacji: EN

Abstrakty

EN

The paper presents an analytical evaluation of transition temperature from upper to lower bainite in Fe-C-Cr steel. The calculations was based on the model constructed by Matas and Hehemann which involves a comparison between the times needed to precipitate cementite within the bainitic ferrite plates (tθ), with the time required to decarburise supersaturated ferrite plates (td). The transition between upper and lower bainite is found to occur over a narrow range of temperatures (350-410°C) and depends on the thickness of bainitic ferrite laths and the volume fraction of precipitated cementite. On comparing the td and tθ times it was found that the transition temperature from upper to lower bainite reaction (LS) of about 350oC could be predicted if the thickness of bainitic ferrite laths is set as wo = 0.1 μm and volume fraction of cementite is set as ξ = 0.01.

Słowa kluczowe

EN

transition temperature; bainite transformation; lower; upper bainite

• Wydawca: Politechnika Gdańska
• Czasopismo: Advances in Materials Science
• Rocznik: 2014
• Tom: Vol. 14, nr 2(40)
• Strony: 14--23
• Opis fizyczny: Bibliogr. 29 poz., rys., tab., wykr.

Twórcy

autor

Ławrynowicz Z.

• University of Technology and Life Sciences, Mechanical Engineering Faculty, Department of Materials Science and Engineering, av. Kaliskiego 7, 85-789 Bydgoszcz, Poland

Bibliografia

• 1. Aaronson H.I., Reynolds W.T., Shiflet G.J.,Spanos G.: Bainite Viewed Three Different Ways. Metall. Trans. A 21A (1990), 1343-1380.
• 2. Bhadeshia H.K.D.H.: Bainite in Steels, The Institute of Materials, London, 1992.
• 3. Bradley J.R., Aaronson H.I.: Growth Kinetics of Grain Boundary Ferrite Allotriomorphs in Fe-CX Alloys. Metall. Trans. A 12A (1981), 729-1741.
• 4. Spanos G et al.: Influence of Carbon Concentration and Reaction Temperature upon Bainite Morphology in Fe-C-2Pct Mn Alloys. Metall. Trans. A 21A (1990), 1391-1411.
• 5. Goldstein H., Aaronson H.I.: Overall Reaction Kinetics and Morphology of Austenite Decomposition between the Upper Nose and the MS of a Hypoeutectoid Fe-C-Cr Alloy. Met. rans. A 21A (1990), 1465-1478.
• 6. Shiflet G.J., Aaronson H.I.: Growth and Overall Transformation Kinetics above the Bay Temperature in Fe-C-Mo Alloys. Metall. Trans. A 21A (1990), 1413-1432.
• 7. Aaronson H.I., Furuhara T., Hall M.G., Hirth J.P., Nie J.F., Purdy G.R., Reynolds Jr. W.T., On the mechanism of formation of diffusional plate-shaped transformation products. Acta Materialia 54 (2006), 1227-1232.
• 8. Spanos G.: The Fine Structure and Formation Mechanism of Lower Bainite. Metall. mater. Trans. 25A (1994), 1967-1980.
• 9. Vetters H.: Transformation of austenite into bainitic ferrite and martensite. Materials technology. 67 (1996), 408-411.
• 10. Honeycombe R.W.K.: Ferrite. Metal Sci. 6 (1980), 201-214.
• 11. Matas S.J., Hehemann R.F.: The Structure of Bainite in Hypoeutectoid Steels. Trans. TMSAIME 221 (1961), 179-185.
• 12. Takahashi M., Bhadeshia H.K.D.H.: Model for transition from upper to lower bainite. Mater. Sci. Technol. 6 (1990), 592-603.
• 13. Christian J.W.: Theory of Transformations in Metals and Alloys, 2nd edition, Pt.1, Pergamon Press, Oxford, 1975.
• 14. Ławrynowicz Z.: Carbon Partitioning During Bainite Transformation in Low Alloy Steels. aterials Science and Technology 18 (2002), 1322-1324.
• 15. Ławrynowicz Z.: Bainite Morphology in Two Experimental Mn-V and Mo-Cr Steels, 13th International Symposium on Advanced Materials (ISAM-2013), Institute of Space Technology, Islamabad, Pakistan, 23 - 27 September, 2013, 13-75.
• 16. Bhadeshia H.K.D.H.: Thermodynamic analysis of isothermal transformation diagrams. Metal Science 16 (1982), 159-165.
• 17. Ławrynowicz Z.: Mechanism of bainite transformation in Fe-Cr-Mo-V-Ti-C steel. International Journal of Engineering 12 (1999), 81-86.
• 18. Bhadeshia H.K.D.H., David S.A., Vitek J.M., Reed R.W.: Stress induced transformation to bainite in Fe-Cr-Mo-C pressure vessel steel. Materials Science and Technology 7 (1991), 686-698.
• 19. Speer J.G., Streicher A.M., Matlock D.K., Rizzo F., Krauss G.: Quenching and partitioning: a fundamentally new process to create high strength TRIP sheet microstructures. [In:] Austenite formation and decomposition, E.B. Damm, M. Merwin (eds). Warrendale, PA: TMS/ISS (2003), 505-522.
• 20. Speer J.G., Edmonds D.V., Rizzo F.C., Matlock D.K.: Partitioning of carbon from supersaturated plates of ferrite, with application to steel processing and fundamentals of the bainite transformation. Current Opinion in Solid State & Materials Science 8 (2004), 219-237.
• 21. Bhadeshia H.K.D.H.: Application of first-order quasichemical theory to transformations in steels. et. Sci. 16 (1982), 167-169.
• 22. Bhadeshia H.K.D.H.: Diffusion of carbon in austenite. Met. Sci. 15 (1981), 477-479.
• 23. Bhadeshia H.K.D.H., Christian J.W.: Bainite in Steels, Metall. Trans. A 21A (1990), 767-797.
• 24. Bhadeshia H.K.D.H., Edmonds D.V.: The Mechanism of Bainite Formation in Steels. Acta Metall. 28 (1980), 1265-1273.
• 25. McLellan R.B., Dunn W.W.: J. Phys. Chem. Solids. 30 (1969), 2631.
• 26. Siller R.H., McLelan R.B.: The Variation with Composition of the Diffusivity of Carbon in Austenite. Trans. of TMS of AIME 245 (1969), 697-700.
• 27. Siller R.H., McLelan R.B.: The Application of First Order Mixing Statistics to the Variation of the Diffusivity of Carbon in Austenite. Metall. Trans. 1 (1970), 985-988.
• 28. Dunn W.W., McLellan R.B.: The Application of a Quasichemical Solid Solution Model to Carbon Austenite. Metall. Trans. 1 (1970), 1263-1265.
• 29. Trivedi R., Pound G.M.: The Effect of Concentration-Dependent Diffusion Coefficient on the Migration of Interphase Boundaries. J. Applied Physics 38 (1967), 3569-3576.