Laminated Fe-34.5 Mn-0.04C composite with high strength and ductility

doi:10.1016/j.jmst.2018.05.013

Abstract

Abstract:

To obtain a good combination of strength and ductility, a laminated composite structure composed of recovered hard lamellae and soft recrystallized lamellae has been produced in a single phase austenitic Fe-34.5 Mn-0.04C steel by cold rolling and partial recrystallization. Enhanced mechanical properties in both strength and ductility have been obtained in the composite structure compared to a fully recrystallized coarse grain structure. A further increase in strength with only minor loss in total elongation has been achieved by a slight cold rolling of the composite structure, which also removes the small yield drop and Lüders elongation observed in the composite structure.

Key words: Laminated composite structure, Partial recrystallization, Constraint effect, Strength, Ductility

Yuhui Wang, Jianmei Kang, Yan Peng, Tiansheng Wang, Niels Hansen, Xiaoxu Huang. Laminated Fe-34.5 Mn-0.04C composite with high strength and ductility[J]. J. Mater. Sci. Technol., 2018, 34(10): 1939-1943.

Figures/Tables 7

Fig. 1. X-ray diffraction patterns of sample after 90% CR.

Fig. 2. TEM images of lamellar structures delineated by (a) GNBs and (b) TBs, and (c) the distribution of boundary spacings for GNBs and TBs in the 90% cold rolled sample.

Fig. 3. (a) EBSD orientation map showing the laminated composite structure, (b) TEM image of a recovered lamellar structure delineated by GNBs, (c) TEM image of a recrystallized fine grain structure, and (d) the distribution of GNB spacings and grain sizes in the sample cold rolled to 90% and annealed for 1 h at 600 °C.

Fig. 4. (a) EBSD orientation map showing the recrystallized grain structure containing annealing twins and (b) the distribution of grain sizes in the sample cold rolled to 90% and annealed for 1 h at 1000 °C.

Table 1 Structural features and tensile properties of Fe-34.5 Mn-0.04C steel samples after different treatments and tested at room temperature.

Sample	Treatment	Structural feature	Yield strength (MPa)	UTS (MPa)	Uniform elongation (%)	Total elongation (%)
1	90% Cold rolling (90% CR)	Lamellar structure delineated by GNBs and TBs	1058 ± 10	1242 ± 9	2.0 ± 0.2	7.3 ± 0.2
2	90% CR + 600 °C, 1h	Laminated composite structure (Partially recrystallized)	455 ± 6	644 ± 7	33.0 ± 0.5	39.4 ± 0.1
3	90% CR + 1000 °C, 1h	Recrystallized equiaxed grain structure	211 ± 3	499 ± 6	31.8 ± 0.5	32.7 ± 0.5
4	90% CR + 600 °C, 1 h + 5% CR	Laminated composite structure + dislocations	600 ± 6	677 ± 6	21.8 ± 0.5	35.7 ± 0.7

Fig. 5. (a) Engineering stress-strain curves of three different samples (sample 1-3, see Table 1) and (b) their corresponding work hardening rates.

Fig. 6. (a) Engineering stress-strain curves of the laminated composite structure (sample 2) and the laminated composite structure plus 5% additional cold rolling (sample 4), and (b) the work hardening rate for sample 4.

References

[1]	Y.T. Zhu, X.Z. Liao, Nat. Mater. 3(2004) 351-352.
[2]	R.Z. Valiev, I.V. Alexandrov, Y.T. Zhu, T.C. Lowe, J. Mater. Res. 17(2002) 5-8.
[3]	M.A. Meyers, A. Mishra, D.J. Benson, Prog. Mater. Sci. 51(2006) 427-556.
[4]	L. Lu, Y.F. Shen, X.H. Chen, L.H. Qian, K. Lu, Science 304 (2004) 422-426.
[5]	X.L. Wu, P. Jiang, L. Chen, F.P. Yuan, Y.T. Zhu, Proc. Natl. Acad. Sci. U. S. A. 111(2014) 7197-7201.
[6]	B. Hu, H.W. Luo, F. Yang, H. Dong, J. Mater. Sci. Technol. 33(2017) 1457-1464.
[7]	X.X. Huang, N. Hansen, N. Tsuji, Science 312 (2006) 249-251.
[8]	T.H. Fang, W.L. Li, N.R. Tao, K. Lu, Science 331 (2011) 1587-1590.
[9]	Y.M. Wang, M.W. Chen, F.H. Zhou, E. Ma, Nature 419 (2002) 912-915.
[10]	X.L. Wu, M.X. Yang, F.P. Yuan, G.L. Wu, Y. Wei, X.X. Huang, Y.T. Zhu, Proc. Natl.Acad. Sci. U. S. A. 112(2015) 14501-14505.
[11]	D. Kuhimann-Wilsdorf, N. Hansen, Scripta Metall. Mater. 25(1991)1557-1562.
[12]	N. Hansen, Mater. Trans. A 32 (2001) 2001-2917.
[13]	J.A. Wert, in: J.V. Carstensen, T. Leffers, T. Lorentzen, O.B. Pedersen, B.F.Sørensen, G. Winther (Eds.), Proc. 19th Ris? Int. Symp. On Materials Science,Risø National Laboratory, Roskilde, 1998, pp. 573-584.
[14]	D.A. Hughes, N. Hansen, Acta Mater. 48(2000) 2985-3004.
[15]	G.L. Wu, D. Juul Jensen, Mater. Sci. Technol. 21(2005) 1407-1411.
[16]	Q. Xing, X.X. Huang, N. Hansen, Mater. Trans. A 37 (2006) 1311-1322.
[17]	X.X. Huang, Q. Xing, D. Juul Jensen, N. Hansen, Mater. Sci.Forum 519-521(2006) 79-84.
[18]	Y. Tomota, M. Strum, J.W. Morris Jr., Metall. Trans. A 17 (1987) 1073-1081.
[19]	O. Gr?ssel, L. Kruger, G. Frommeyer, L.W. Meyer, Int. J. Plast. 16(2000)1391-1409.
[20]	L.Q. Chen, Y. Zhao, X.M. Qin, Acta Metall. Sin. (Engl. Lett.) 26(2013) 1-15.
[21]	S.S. Sohn, S. Hong, J. Lee, B.C. Suh, S.K. Kim, B.J. Lee, N.J. Kim, S. Lee, Acta Mater.100(2015) 39-52.
[22]	X.Y. Yuan, Y. Zhao, X. Li, L.Q. Chen, J. Mater. Sci. Technol. 33(2017) 1555-1560.
[23]	Q. Liu, X.X. Huang, D.J. Lloyd, N. Hansen, Acta Mater. 50(2002) 3789-3802.
[24]	M.F. Ashby, Philos. Mag. 21(1970) 399-411.
[25]	N. Tsuji, Y. Ito, Y. Saito, Y. Minamino, Scripta Mater. 47(2002) 893-899.
[26]	C.Y. Yu, P.W. Kao, C.P. Chang, Acta Mater. 53(2005) 4019-4028.
[27]	N. Kamikawa, X. Huang, N. Tsuji, N. Hansen, Acta Mater. 570(2009)4198-4208.
[28]	S. Gao, M.C. Chen, M. Joshi, A. Shibata, N. Tsuji, J. Mater. Sci. 49(2014)6536-6542.
[29]	R. Ueji, N. Tsuchida, D. Terada, N. Tsuji, Y. Tanaka, A. Takemura, K. Kunishige,Scripta Mater. 59(2008) 963-966.
[30]	Z. Li, L. Fu, B. Fu, A.D. Shan, Mater. Lett. 96(2013) 1-4.
[31]	X. Huang, Scripta Mater. 60(2009) 1078-1082.