Effect of Alloying Elements on Microstructure and Mechanical Properties of Air-Cooled Bainitic Steel
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In the present investigation, a carbide-free bainitic steel has been produced in the laboratory through the air cooling route. Optimization of the alloying elements was done based on thermodynamic and kinetic calculations. Emphasis was given to obtain ultrafine bainitic microstructure by maximizing the driving force and lowering the transformation temperature of bainite formation. In addition to bainite, the microstructure contained a small amount of austenite and martensite. It was observed that Mn decreases ΔGγ → α to a greater extent as compared to Cr and Si. Therefore, a low Mn-high Cr alloy exhibited large driving force and low Bs temperature. Si promoted carbon partitioning in the adjacent austenite to make it more stable. Therefore, the transformation of deformation-induced martensite from the retained austenite during the deformation process was restricted, resulting in higher toughness of the alloy. Thus, the air-cooled bainitic steel produced in lab scale showed better strength, toughness, and hardness than the conventional bainitic steel produced by the isothermal route.
The authors are thankful to the director, CSIR–National Metallurgical Laboratory, for his kind permission to publish this work. The fruitful technical discussion with Dr. M. Ghosh, Sr. Scientist, CSIR-NML, is gratefully acknowledged.
- 10.D. Seferian: Metallurgy of Welding, Mashgiz, Moscow, 1963, p. 268 (in Russian).Google Scholar
- 15.E. Vuorinen, A. Linström, P. Rubin, E. Navara, and M. Oden: Pellets 2006: Proc. 2nd World Conf. on ‘Pellets,’ Jonkoping, Sweden, June 2006, Swedish Bioenergy Association (SVEBIO), Stockholm, 2006, pp. 151–55.Google Scholar
- 16.Hong-Sheng Fang, Qi Li, Bing-Zhe Bai, Zhi-Gang Yang, Dong-Yu Liu, and Fu-Bao Yang: Int. J. ISSI, 2005, vol. 2, pp. 9–18.Google Scholar
- 20.H.K.D.H. Bhadeshia: Bainite in Steels: Theory and Practice, 3rd ed., Maney Publishing, Leeds 2015, p. 286.Google Scholar
- 21.F.B. Pickering and T. Gladman: Iron Steel Inst., 1963, vol. 81, p. 10.Google Scholar
- 22.A.S. Keh and S. Weissmann: Electron Microscopy and the Strength of Crystals, Interscience, New York, NY, 1963, pp. 231–300.Google Scholar
- 27.H.K.D.H. Bhadeshia and D.V. Edmonds: Mater. Sci., 1983, vol. 17, pp. 420–25.Google Scholar
- 29.H.K.D.H. Bhadeshia: Bainite in Steels, The Institute of Materials, Cambridge University Press, Cambridge, United Kingdom, 1992.Google Scholar
- 30.E. Kozeschnik and H.K.D.H. Bhadeshia: Mater. Sci. Technol., 2013, vol. 4, pp. 343–47.Google Scholar
- 31.Mathew Peet and H.K.D.H. Bhadeshia: MUCG 83. Mater. Algor. Proj., 2011.Google Scholar
- 32.K.W. Andrews: J. Iron Steel Inst., 1965, vol. 203, pp. 721–27.Google Scholar
- 33.W. Steven and A.G. Haynes: J. Iron Steel Inst., 1956, vol. 183, p. 349–359.Google Scholar
- 35.J.S. Kirkaldy and D. Venugopalan: in Phase Transformations in Ferrous Alloys, A.R. Marder and J.I. Goldstein, eds., TMS-AIME, Warrendale, PA, 1984, p. 125–48.Google Scholar
- 39.Kazuo Yamanaka and Yasuya Ohmori: ISIJ, 1977, vol. 17, p. 92.Google Scholar
- 41.B.D. Cullity: Elements of X-Ray Diffraction, 2nd ed., Addison-Wesley Publishing Company Inc., Palo Alto, CA, 1978, pp. 363–66.Google Scholar
- 44.D.J. Dyson and B. Holmes: J. Iron Steel Inst., 1970, vol. 208, pp. 469–74.Google Scholar
- 45.M.J. Peet: http://mathewpeet.org/thesis/programs/, 2009.Google Scholar
- 46.JMat Pro: http://www.sentesoftware.co.uk/jmatpro.aspx.
- 47.L.J. Habraken and M. Ecomopoulos: Transformation and Hardenibility in Steels, Climax Molybdenum Co., Ann Arbor, MI, 1967, pp. 69–106.Google Scholar
- 52.T. Angel: J. Iron Steel Inst., 1954, vol. 177, pp. 165–74.Google Scholar