Thermomechanical process and tempering heat treatment were employed to produce the experimental steel plates. The effect of boron addition on the microstructure and mechanical properties of low carbon bainitic steels was studied in this paper. Microstructure observation and crystallographic features were conducted by using optical microscopy, SEM, TEM and electron back scattering diffraction (EBSD) analysis. The results showed that under the same rolling processes and heat treatment conditions, a substantial increase in strength is obtained by addition of boron into steel, but accompanied by an obvious drop in toughness. New martensite phase forms along the grain boundaries on tempering at 650 ℃ mainly due to boron segregation, which can further deteriorate impact toughness of the boron bearing steel. The EBSD analysis showed that high angle grain boundary is not responsible for the deteriorated toughness of the boron bearing steel because it has relatively higher percentage of high angle grain boundary than the boron free steel. The low toughness of the boron bearing steel is mainly attributed to the coarse boride precipitated particles according to the results of fractograph observation.
LAN Liang-Yun
,
QIU Chun-Lin
,
DIAO De-Wen
. Effect of boron addition on the microstructures and mechanical properties of thermomechanically processed and tempered low carbon bainitic steels[J]. Acta Metallurgica Sinica (English Letters), 2011
, 24(6)
: 473
-486
.
DOI: 10.11890/1006-7191-116-473
[1] L.D. Yao, X.T. Zhao and S.X. Zhao, US Patent US 0032062A1 (11 February 2010).
[2] J.R. Yang, C.Y. Huang and S.C. Wang, Mater Des 13(6) (1992) 335.
[3] W.B. Morrison, Mater Sci Technol 25(9) (2009)1066.
[4] P. Maitrepierre, D. Thivellier and R. Tricot, Metall Trans A 6 (1975) 287.
[5] H.J. Jun, J.S. Kang, D.H. Seo, K.B. Kang and C.G. Park, Mater Sci Eng A 422 (2006) 157.
[6] X.M. Wang and X.L. He, ISIJ Int 42(sp) (2002)s38.
[7] G.F. Melloy, P.R. Slimmon and P.P. Podgursky, Metall Trans A 4 (1973) 2279.
[8] H. Tamehiro, M. Murata, R. Habu and M. Nagumo, Trans ISIJ 27(2) (1987) 120.
[9] S.C. Wang and P.W. Kao, J Mater Sci 28 (1993)5169.
[10] W. Yan, L. Zhu, W. Sha, Y.Y. Shan and K. Yang, Mater Sci Eng A 517 (2009) 369.
[11] S. Gunduz and R.C. Cochrane, Mater Des 26 (2005) 486.
[12] S.K. Dhua, A. Ray and D.S. Sarma, Mater Sci Eng A 318 (2001) 197.
[13] A. Ghosh, S. Das and S. Chatterjee, Mater Sci Eng A 486 (2008) 152.
[14] X.L. He, M. Djahazi, J.J. Jonas and J. Jackman, Acta Metall Mater 39(10) (1991) 2295.
[15] R.G. Faulkner, J Mater Sci 16 (1981) 373.
[16] R.D.K. Misra, H. Nathani, J.E. Hartmann and F. Siciliano, Mater Sci Eng A 394 (2005) 339.
[17] M. Djahazi, X.L. He, J.J. Jonas and W.P. Sun, Mater Sci Technol 8 (1992) 628.
[18] D.V. Edmonds and R.C. Cochrane, Metall Trans A 21 (1990) 1527.
[19] S.K. Das, S. Chatterjee and S. Tarafder, J Mater Sci 44 (2009) 1094.
[20] M. Mujahid, A.K. Lis, C.I. Garcia and A.J. Deardo, J Mater Eng Perform 7(2) (1998) 247.
[21] G. Krauss and S.W. Thompson, ISIJ Int 35(8) (1995) 937.
[22] X.H. Yu, J.L. Caron, S.S. Babu, J.C. Lippold, D. Isheim and D.N. Seidman, Acta Mater 58 (2010) 5596.
[23] G.F. Zhou, M.B. Wen, P.H. Li and X.L. He, Acta Metall Sin (Engl Lett) 13(2) (2000) 623.
[24] S.K. Ghosh, N. Bhowmik, A, Haldar and P.P. Chattopadhyay, Mater Sci Eng A 527 (2010) 1082.
[25] M. Charleux, W.J. Poole, M. Militzer and A. Deschamp, Metall Mater Trans A 32 (2001) 1635.
[26] A. Echeverria and J.M. Rodriguez-Ibabe, Mater Sci Eng A 346 (2003) 149.
[27] F.M. Beremin, Metall Trans A 12 (1981) 723.
[28] J.M. Rodriguez-Ibabe, Mater Sci Forum 284-286 (1998) 51.
[29] L. Ryde, Mater Sci Technol 22 (2006) 1297.
[30] A.M. Guo, R.D.K. Misra, J.B. Liu, L. Chen, X.L. He and S.J. Jansto, Mater Sci Eng A 527 (2010) 6440.
[31] M. Diaz-Fuentes, A. Iza-Mendia and I. Gutierrez, Metall Mater Trans A 34 (2003) 2505.
[32] E. Smith and J.T. Barnby, Metal Sci J 1 (1967)56.
[33] G. Thewlis, Mater Sci Technol 10 (1994) 110.
[34] A. Ghosh, S. Das and S. Chatterjee, Mater Sci Technol 21(3) (2005) 325.
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