Microstructure and Mechanical Properties of 1,000 MPa Ultra-High Strength Hot-Rolled Plate Steel for Coal Mine Refuge Chamber

doi:10.1007/s40195-014-0074-y

Abstract

Abstract:

The 1,000 MPa ultra-high strength hot-rolled plate steel with low-carbon bainitic microstructure was developed in the laboratory for coal mine refuge chamber. The static recrystallization behavior, microstructure evolution, and mechanical properties of this hot-rolled plate steel were investigated by the hot compression, continuous cooling transformation, and tensile deformation test. The results show that the developed steel has excellent mechanical properties at both room and elevated temperature, and its microstructure mainly consists of lath bainite, granular bainite, and ferrite after thermal–mechanical control process (TMCP). The ultra-high strength plate steel is obtained by the TMCP process in hot rolling, strengthened by bainitic transformation, microstructure refinement, and precipitation of alloying elements such as Nb, Ti, Mo, and Cu. The experimental steel has relatively low welding crack sensitivity index and high atmospheric corrosion resistance index. Therefore, the developed steel has a good balance of strength and ductility both at room and elevated temperature, weldability and corrosion resistance, and it can suffice for the basic demands for materials in the manufacture of coal mine refuge chamber.

Key words: Ultra-high strength steel, Low-carbon bainite, Coal mine refuge chamber, Microstructure, Mechanical property

Changsheng Li, Biao Ma, Tao Li, Tao Zhu. Microstructure and Mechanical Properties of 1,000 MPa Ultra-High Strength Hot-Rolled Plate Steel for Coal Mine Refuge Chamber[J]. Acta Metallurgica Sinica (English Letters), 2014, 27(3): 422-429.

Figures/Tables 11

Fig. 1 The schematic diagram of double pass compression tests of the experimental steel

Fig. 2 The schematic diagram for CCT schedule of the experimental steel

Table 1 The actual TMCP parameters of the experimental steel

Processes	Initial rolling temperature (°C)	Finish rolling temperature (°C)	Initial cooling temperature (°C)	Finish cooling temperature (°C)	Cooling rate (°C/s)
R1	1,057	976	935	525	42
R2	1,100	946	882	502	42
R3	1,040	910	886	616	34
R4	1,034	913	890	Air cooled	Air cooled

Fig. 3 The CCT diagram of the experimental steel

Fig. 4 Optical micrographs of the experimental steels at process R1 a, process R2 b, process R3 c, process R4 d

Fig. 5 SEM micrographs of the experimental steels at process R1 a, process R2 b, process R3 c, process R4 d

Fig. 6 TEM morphologies showing the bainitic substructure a, precipitates b, the EDS result of the precipitates in steel at process R2 c

Table 2 The tensile properties of the steel at processes R1–4 at room temperature

Processes	Yield strength (MPa)	Tensile strength (MPa)	Elongation (%)	Yield ratio
R1	745	950	12.5	0.78
R2	850	1,020	11.6	0.83
R3	580	810	15.4	0.72
R4	640	830	13.6	0.77

Table 3 The tensile properties of the steel at processes R1–4 at 500 °C

Processes	Yield strength (MPa)	Tensile strength (MPa)	Elongation (%)	Yield ratio
R1	660	820	16.7	0.8
R2	710	840	15.2	0.85
R3	520	702	18.2	0.74
R4	575	704	16.4	0.81

Fig. 7 The impact fracture morphology of the experimental steel at -20 °C with process R1 a, process R2 b, process R3 c, process R4 d

Fig. 8 SEM micrographs of the inclusion located on the fracture a, the energy spectrum of the inclusion b

References 24

[1]	X.D. Yang, L.Z. Jin, Appl. Mech. Mater. 170–173, 1608(2012)10.4028/www.scientific.net/AMM.170-173.1608
[2]	H. Ghazanfari, M. Naderi, Acta Metall. Sin. (Engl. Lett.) 26, 635(2013)10.1007/s40195-013-0076-1
[3]	H.F. Fang, S.R. Ge, L.H. Cai, E.Y. Hu, Int. J. Min. Sci. Technol. 22, 85(2012)10.1016/j.ijmst.2011.06.008
[4]	F.L. Sun, X.G. Li, F. Zhang, X.Q. Cheng, C. Zhou, N.C. Wu, Y.Q. Yin, J.B. Zhao, Acta Metall. Sin. (Engl. Lett.) 26, 257(2013)10.1007/s40195-012-0231-0
[5]	W. Sheng, M.Z. Gao, L. Yang, Process Eng. 26, 2351(2011)
[6]	H.J. Zhao, X.M. Qian, J. Li, Saf. Sci. 50, 674(2012)10.1016/j.ssci.2011.08.053
[7]	F.G. Caballelo, H.K.D.H. Bhadeshia, K.J.A. Mawella, Mater. Sci. Technol. 17, 512(2001)10.1179/026708301101510348
[8]	C.I. Gareia, S.M. Aklis, Mater. Sci. Technol. 13, 102(1992)
[9]	B.C. Hwang, C.G. Lee, T.H. Lee, Metall. Mater. Trans. A 41, 85(2010)10.1007/s11661-009-0070-4
[10]	J. Majta, J.G. Lenard, M. Pietrzyk, Mater. Sci. Eng. A 208, 249(1999)10.1016/0921-5093(95)10050-4
[11]	W.W. Bose-Filho, A.L.M. Carvalho, M. Strangwood, Mater. Charact. 58, 28(2007)
[12]	A. Yamamoto, S. Yamauchi, M. Hamada, T. Ikeda, N. Takahashi, U.S. Patent 20,040,129,348, 8 July 2004
[13]	Y.L. Shen, R.L. Bodnar, J.Y. Yoo, W.Y. Choo, U.S. Patent 6,187,117 B1, 13 Feb 2001
[14]	S.F. Medina, A. Quispe, M. Gómez, Mater. Sci. Technol. 17, 536(2001)10.1179/026708301101510177
[15]	H.Y. Wu, L.X. Du, Z.R. Ai, X.H. Liu, J. Mater. Sci. Technol. 29, 1197(2013)10.1016/j.jmst.2013.10.030
[16]	S.F. Medina, A. Quispe, ISIJ lnt. 41, 774(2001)10.2355/isijinternational.41.774
[17]	S.H. Cho, K.B. Kang, J.J. Jonas, ISIJ Int. 41, 766(2001)10.2355/isijinternational.41.766
[18]	Z.Y. Zeng, L.Q. Chen, F.X. Zhu, X.H. Liu, Acta Metall. Sin. (Engl. Lett.) 24, 381(2011)
[19]	K.Y. Xie, L. Yao, C. Zhu, J.M. Cairney, C.R. Killmore, F.J. Barbaro, J.G. Williams, S.P. Ringer, Metall. Mater. Trans. A 42, 2199(2011)10.1007/s11661-011-0622-2
[20]	R.D.K. Misra, H. Nathani, J.E. Hartmann, F. Siciliano, Mater. Sci. Eng. A 394, 339(2005)10.1016/j.msea.2004.11.041
[21]	H.J. Jun, J.S. Kang, D.H. Seo, K.B. Kang, C.G. Park, Mater. Sci. Eng. A 422, 157(2006)10.1016/j.msea.2005.05.008
[22]	Z.H. Tang, W. Stumpf, Mater. Sci. Eng. A 490, 391(2008)10.1016/j.msea.2008.01.060
[23]	A. Ghosh, B. Mishra, S. Das, S. Chatterjee, Mater. Sci. Eng. A 374, 43(2004)10.1016/j.msea.2003.11.047
[24]	W.B. Lee, S.G. Hong, C.G. Park, S.H. Park, Metall. Mater. Trans. A 33, 1689(2002)10.1007/s11661-002-0178-2