Dynamic observation of bainite transformation in a Fe-C-Mn-Si superbainite steel

Haijiang Hu1,2, Guang Xu1, Yulong Zhang2, Zhengliang Xue1, Mingxing Zhou1
1The State Key Laboratory of Refractories and Metallurgy, Hubei Collaborative Innovation Center for Advanced Steels, Wuhan University of Science and Technology, Wuhan, China
2State Key Laboratory of Development and Application Technology of Automotive Steels (Baosteel Group), Shanghai, China

Tóm tắt

The dynamic observations of bainitic transformation in a Fe-C-Mn-Si superbainite steel were conducted on a high temperature laser scanning confocal microscope. It is indicated that the mutual intersection of bainite sheaves often occurs during growth of bainite ferrite, resulting in an interlocked bainite microstructure. Moreover, bainite transformation is promoted by higher austenization temperature and the longer and finer bainite platelets are obtained. Further, The average growth rate of bainite after austenization at 1 100 ° is calculated as 5.8 µm·s−1. In situ observation investigation makes it possible to identify bainite transformation in real time during isothermal holding.

Tài liệu tham khảo

Zhu KY, Oberbillig C, Musik C, et al. Effect of B and B + Nb on the Bainitic Transformation in Low Carbon Steels[J]. Mater. Sci. Eng. A, 2011, 528(12): 4222 Das S, Timokhina I, Singh SB, et al. Effect of Bainitic Transformation on Bake Hardening in TRIP Assisted steel[J]. Mater. Sci. Eng. A, 2012, 534: 485 Lambers HG, Canadinc D, Maier HJ. Evolution of Transformation Plasticity in Austenite-to-bainite Phase Transformation: A Multi Parameter Problem[J]. Mater. Sci. Eng. A, 2012, 541(8): 73 Li HY, Lu XW, Wu XC, et al. Bainitic Transformation during the Two-Step Quenching and Partitioning Process in a Medium Carbon Steel Containing Silicon[J]. Mater. Sci. Eng. A, 2010, 527(23): 6255 Zhang D, Terasaki H, Komizo YI. In situ Observation of Phase Transformation in Fe-0.15C Binary Alloy[J]. J. Alloys Compd., 2009, 484 (1-2): 929 Kolmskog P, Borgenstam A, Hillert M, et al. Direct Observation that Bainite Can Grow Below MS[J]. Metall. Mater. Trans. A, 2012, 43(13): 4984 Kang MK, Zhang MX, Zhu M. In situ Observation of Bainite Growth during Isothermal Holding[J]. Acta Mater., 2006, 54(8): 2121 Yada H, Enomoto M, Sonoyama T. Lengthening Kinetics of Bainitic Plates in Iron-nickel-carbon Alloys[J]. ISIJ Int., 1995, 35(8): 976 Xu G, Liu F, Wang L, et al. A new Approach to Quantitative Analysis of Bainitic Transformation in a Superbainite Steel[J]. Scripta Mater., 2013, 68: 833 Kang MK, Zhu M, Zhang MX. Mechanism of Bainite Nucleation in Steel, Iron and Copper Alloys[J]. J. Mater. Sci. Techol., 2005, 21(4): 437 Bhadeshia HKDH. The Bainite Transformation: Unresolved Issues[J]. Mater. Sci. Eng. A, 1999, 273-275: 58