Skip to main content
Log in

Simulation Kinetics of Austenitic Phase Transformation in Ti+Nb Stabilized IF and Microalloyed Steels

  • Published:
Journal of Materials Engineering and Performance Aims and scope Submit manuscript

Abstract

In the present study, the influence of cooling rates (low to ultrafast) on diffusion controlled and displacive transformation of Ti-Nb IF and microalloyed steels has been thoroughly investigated. Mechanisms of nucleation and formation of non-equiaxed ferrite morphologies (i.e., acicular ferrite and bainitic ferrite) have been analyzed in details. The continuous cooling transformation behavior has been studied in a thermomechanical simulator (Gleeble 3800) using the cooling rates of 1-150 °C/s. On the basis of the dilatometric analysis of each cooling rate, continuous cooling transformation (CCT) diagrams have been constructed for both the steels to correlate the microstructural features at each cooling rate in different critical zones. In the case of the IF steel, massive ferrite grains along with granular bainite structures have been developed at cooling rates > 120 °C/s. On the other hand, a mixture of lath bainitic and lath martensite structures has been formed at a cooling rate of ~ 80 °C/s in the microalloyed steel. A strong dependence of the cooling rates and C content on the microstructures and mechanical properties has been established. The steel samples that were fast cooled to a mixture of bainite ferrite and martensite showed a significant improvement of impact toughness and hardness (157 J, for IF steel and 174 J for microalloyed steel) as compared to that of the as-received specimens (133 J for IF steel and 116 J for microalloyed steel). Thus, it can be concluded that the hardness and impact toughness properties are correlated well with the microstructural constituents as indicated by the CCT diagram. Transformation mechanisms and kinetics of austenitic transformation to different phase morphologies at various cooling rates have been discussed in details to correlate microstructural evolution and mechanical properties.

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. R. Kuziak, T. Bołd, and Y. Cheng, Microstructure Control of Ferrite-Pearlite High Strength Low Alloy Steels Utilizing Microalloying Additions, J. Mater. Process. Technol., 1995, 53, p 255–262

    Article  Google Scholar 

  2. T. Gladman, The Physical Metallurgy of Microalloyed Steels, The Institute of Materials, London, 1997

    Google Scholar 

  3. S. Ghosh and S. Mula, Thermomechanical Processing of Low Carbon Nb-Ti Stabilized Microalloyed Steel: Microstructure and Mechanical Properties, Mater. Sci. Eng. A, 2015, 646, p 218–233

    Article  Google Scholar 

  4. Y. Maehara and N. Mizui, Physical Metallurgy of IF Steels, Tokyo, ISIJ, 1993, p 233

    Google Scholar 

  5. S. Hoile, Processing and Properties of Mild Interstitial Free Steels, Mater. Sci. Technol., 2000, 16, p 1079–1093

    Article  Google Scholar 

  6. R.K. Ray and P. Ghosh, An Overview on Precipitation and Texture Formation in IF and IFHS Steels During Processing, Mater. Manuf. Process., 2010, 25, p 195–201

    Article  Google Scholar 

  7. S. Ghosh, A.K. Singh, S. Mula, P. Chanda, V.V. Mahashabde, and T.K. Roy, Mechanical Properties, Formability and Corrosion Resistance of Thermomechanically Controlled Processed Ti-Nb Stabilized IF Steel, Mater. Sci. Eng. A, 2017, 684, p 22–36

    Article  Google Scholar 

  8. H.K.D.H. Bhadeshia, The Bainite Transformation: Unresolved Issues, Mater. Sci. Eng. A, 1999, 273–275, p 58–66

    Article  Google Scholar 

  9. H.K.D.H. Bhadeshia, Bainite in Steels: Transformations, Microstructure and Properties, IOM Communications Ltd., London, 2001

    Google Scholar 

  10. F.R. Xiao, B. Liao, and Y.Y. Shan, Challenge of Mechanical Properties of an Acicular Ferrite Pipeline Steel, Mater. Sci. Eng. A, 2006, 431, p 41–52

    Article  Google Scholar 

  11. W. Wang, W. Yan, and L. Zhu, Relation Among Rolling Parameters, Microstructures and Mechanical Properties in an Acicular Ferrite Pipeline Steel, Mater. Des., 2009, 30, p 3436–3443

    Article  Google Scholar 

  12. F. Xiao, B. Liao, and D. Ren, Acicular Ferritic Microstructure of a Low-Carbon Mn-Mo-Nb Microalloyed Pipeline Steel, Mater. Charact., 2005, 54, p 305–314

    Article  Google Scholar 

  13. P. Gong, E.J. Palmiere, and W.M. Rainforth, Dissolution and Precipitation Behavior in Steels Microalloyed with Niobium During Thermomechanical Processing, Acta Mater., 2015, 97, p 392–403

    Article  Google Scholar 

  14. S.W. Thompson, D.J. Colvin, and G. Krauss, Continuous Cooling Transformations and Microstructures in a Low-Carbon, High Strength Low Alloy Plate Steel, Metall. Trans. A, 1990, 21, p 1493–1507

    Article  Google Scholar 

  15. Y. Chen, L. Chen, X. Zhou, Y. Zhao, X. Zha, and F. Zhu, Effect of Continuous Cooling Rate on Transformation Characteristic in Microalloyed Low Carbon Bainite Cryogenic Pressure Vessel Steel, Trans. Ind. Inst. Met., 2016, 69, p 817–821

    Article  Google Scholar 

  16. H. Bhadeshia, E. Keehan, L. Karlsson, and H.O. Andren, Coalesced Bainite, Trans. Ind. Inst. Met., 2006, 59, p 689–694

    Google Scholar 

  17. Z.M. Zhang, Q.W. Cai, W. Yu, X.L. Li, and L.D. Wang, Continuous Cooling Transformation Behavior and Kinetic Models of Transformations for an Ultra-Low Carbon Bainitic Steel, J Iron Steel Res. Int., 2012, 19, p 73–78

    Google Scholar 

  18. C. Capdevila, F.G. Caballero, C.G. Mateo, and C.G. Andres, The Role of Inclusions and Austenite Grain Size on Intragranular Nucleation of Ferrite in Medium Carbon Microalloyed Steels, Mater. Trans., 2004, 45, p 2678–2685

    Article  Google Scholar 

  19. S.R. Dey, E. Bouzy, and A. Hazotte, Intragranular Nucleation Sites of Massive γ Grains in a TiAl-Based Alloy, Scr. Mater., 2007, 57, p 365–368

    Article  Google Scholar 

  20. K.T. Park, S.W. Hwang, J.H. Ji, and C.H. Lee, Inclusions Nucleating Intragranular Polygonal Ferrite and Acicular Ferrite in Low Alloyed Carbon Manganese Steel Welds, Met. Mater. Int., 2011, 17, p 349–356

    Article  Google Scholar 

  21. G. Krauss and S.W. Thompson, Ferritic Microstructure in Continuously Cooled Low and Ultralow Carbon Steels, ISIJ Int., 1995, 35, p 937–945

    Article  Google Scholar 

  22. B. Jonson and J. Agren, On the Massive Transformation, Acta. Metall. Mater., 1990, 38, p 433–438

    Article  Google Scholar 

  23. I.A. Rauf and J.D. Boyd, Microstructural Evolution During Thermomechanical Processing of a Ti-Nb Interstitial-Free Steel Just Below the Ar3 Temperature, Metall. Mater. Trans. A, 1997, 28, p 1437–1443

    Article  Google Scholar 

  24. J.Y. Kang, S.C. Kim, J.O. Oh, H.N. Han, K.H. Oh, and H.C. Lee, Martensite in Interstitial-Free Steel Obtained by Ultra-High Pressure, Scripta Mater., 2012, 66, p 45–48

    Article  Google Scholar 

  25. H.K.D.H. Bhadeshia, Diffusional Formation of Ferrite in Iron and Its Alloys, Prog. Mater. Sci., 1985, 29, p 321–386

    Article  Google Scholar 

  26. P.S. Bandyopadhyay, S. Kundu, S.K. Ghosh, and S. Chatterjee, Structure and Properties of a Low-Carbon, Microalloyed, Ultra-High-Strength Steel, Metall. Mater. Trans A, 2011, 42, p 1051–1061

    Article  Google Scholar 

  27. T. Zhang, Z. Li, S. Ma, S. Kou, and H. Jing, High Strength Steel (600–900 MPa) Deposited Metals: Microstructure and Mechanical Properties, Sci. Technol. Weld Join, 2016, 21, p 186–193

    Article  Google Scholar 

  28. Z.T. Duan, Y.M. Li, F.X. Zhu, and H.Y. Zhang, Continues Cooling Transformation Behavior of Low Carbon Mn-Nb-B Steel, Adv. Mater. Res., 2011, 335, p 595

    Article  Google Scholar 

  29. J. Wang, P.J. Van der Wolk, and S. Van der Zwaag, On the Influence of Alloying Elements on the Bainite Reaction in Low Alloy Steels During Continuous Cooling, J. Mater. Sci., 2000, 35, p 4393–4404

    Article  Google Scholar 

  30. E.A. Wilson, γ → α Transformation in Fe, Fe-Ni, and Fe-Cr Alloys, Met. Sci., 1984, 18, p 471–484

    Article  Google Scholar 

  31. M. Hillert and B. Sundman, A Solute-Drag Treatment of the Transition from Diffusion-Controlled to Diffusion Less Solidification, Acta Metall., 1977, 25, p 11–18

    Article  Google Scholar 

  32. M. Zhang, L. Li, R.Y. Fu, D. Krizan, and B.C. De Cooman, Continuous Cooling Transformation Diagrams and Properties of Micro-alloyed TRIP Steels, Mater. Sci. Eng. A, 2006, 438–440, p 296–299

    Article  Google Scholar 

  33. S. Chatterjee and S.K. Ghosh, Evolution of Microstructures and Mechanical Properties of Thermomechanically Processed Ultrahigh Strength Steels, Int. J. Metall. Eng., 2013, 2, p 92–99

    Google Scholar 

  34. N. Tsuji, Y. Matsubara, T. Sakai, and Y. Saito, Effect of Boron Addition on the Microstructure of Hot-Deformed Ti-Added Interstitial Free Steel, ISIJ Int., 1997, 37, p 797–806

    Article  Google Scholar 

  35. S.I. Kim and Y. Lee, Influence of Cooling Rate and Boron Content on the Microstructure and Mechanical Properties of Hot-Rolled High Strength Interstitial-Free Steels, Met. Mater. Int., 2012, 18, p 735–744

    Article  Google Scholar 

Download references

Acknowledgments

The authors highly acknowledge the Institute Instrumentation Centre (IIC) and Department of Metallurgical and Materials Engineering, IIT Roorkee for providing the facilities and support to carry out the research work.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Suhrit Mula.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Ghosh, S., Dasharath, S.M. & Mula, S. Simulation Kinetics of Austenitic Phase Transformation in Ti+Nb Stabilized IF and Microalloyed Steels. J. of Materi Eng and Perform 27, 2595–2608 (2018). https://doi.org/10.1007/s11665-018-3358-y

Download citation

  • Received:

  • Revised:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s11665-018-3358-y

Keywords

Navigation