Effect of Microstructure on Tensile Behavior and Mechanical Stability of Retained Austenite in a Cold-Rolled Al-Containing TRIP Steel

doi:10.1007/s40195-019-00890-7

Abstract

Abstract:

In the present study, a quenching treatment prior to two-stage heat treatment was conducted on a Fe-0.28C-1.55Mn-2.06Al transformation-induced plasticity steel to tailor the final microstructure. Compared with the microstructure of the ferrite, bainite and blocky retained austenite obtained by conventional two-stage heat treatment, the microstructure subjected to quenching plus two-stage heat treatment was composed of the ferrite, lath bainite and film-like retained austenite. The corresponding tensile behavior and mechanical stability of retained austenite were investigated by scanning electron microscopy, transmission electron microscopy and X-ray diffraction. The results show that the mechanical stability of blocky retained austenite grains is lower and most of them transform to martensite during the tensile deformation, which leads to higher ultimate tensile strength and instantaneous work hardening exponent. Film-like retained austenite has relatively higher stability, which could cause sustained work hardening and high ductility as well as product of strength and elongation.

Key words: Transformation-induced plasticity (TRIP) steel, Retained austenite stability, Microstructure, Mechanical properties, Work hardening behavior

Yang Zhao, Wen-Ting Zhu, Shu Yan, Li-Qing Chen. Effect of Microstructure on Tensile Behavior and Mechanical Stability of Retained Austenite in a Cold-Rolled Al-Containing TRIP Steel[J]. Acta Metallurgica Sinica (English Letters), 2019, 32(10): 1237-1243.

Figures/Tables 9

Fig. 1 Schematic diagram of heat treatments: a Process A; b Process B

Fig. 2 SEM micrographs of experimental steel treated by different heat treatment processes: a cold-rolled sample; b sample A; c sample B

Fig. 3 Representative TEM images of blocky retained austenite in sample A: a bright field image; b dark field image; c SAEDP of blocky retained austenite in circled area in a

Fig. 4 Representative TEM images of film-like retained austenite in sample B: a bright field image; b dark field image; c SAEDP of film-like retained austenite in circled area in a

Fig. 5 EBSD maps of retained austenite in as-heat-treated samples: a sample A; b sample B

Fig. 6 Engineering stress-strain curves of samples A and B at room temperature

Table 1 Tensile properties of samples A and B at room temperature

Sample	YS (MPa)	UTS (MPa)	El (%)	UTS × El (GPa %)
A	489	873	26.7	23.3
B	538	764	33.3	25.4

Fig. 7 Variation in nisnt values with true strain of samples A and B

Fig. 8 Relationship between volume fraction of retained austenite and engineering strain

References

[1]	L.N. Wang, P. Yang, T. Jin, W.M. Mao, Acta Metall. Sin. (Engl. Lett.) 31, 449(2018)
[2]	Y. Zhao, Q. Yan, L. Chen, X. Yuan, Acta Metall. Sin. (Engl. Lett.) 27, 389(2014)
[3]	B.C. De Cooman, Curr. Opin.Solid State Mater. Sci. 8, 285(2004)
[4]	P. Xie, M. Han, C.L. Wu, Y.Q. Yin, K. Zhu, R.H. Shen, J.H. Chen, Mater. Des. 127, 1(2017)
[5]	Y. Chen, X. Chen, Q.F. Wang, Acta Metall. Sin. (Engl. Lett.) 15, 339(2002)
[6]	G. Azizi, H. Mirzadeh, M.H. Parsa, Acta Metall. Sin. (Engl. Lett.) 28, 1272(2015)
[7]	Z.P. Xiong, A.A. Saleh, R.K.W. Marceau, A.S. Taylor, N.E. Stanford, A.G. Kostryzhev, E.V. Pereloma, Acta Mater. 134, 1(2017)
[8]	M. De Meyer, D. Vanderschueren, B.C. De Cooman, ISIJ Int. 39, 813(1999)
[9]	L. Barbé, K. Verbeken, E. Wettinck, ISIJ Int. 46, 1251(2006)
[10]	D.W. Suh, S.J. Park, C.S. Oh, S.J. Kim, Scr. Mater. 57, 1097(2007)
[11]	J. Mahieu, B.C. De Cooman, J. Maki, Mater. Trans. A 33, 2573 (2002)
[12]	J. Chiang, B. Lawrence, J.D. Boyd, A.K. Pilkey, Mater. Sci. Eng., A 528, 4516 (2011)
[13]	Y.F. Shen, L.N. Qiu, X. Sun, L. Zuo, P.K. Liaw, D. Raabe, Mater. Sci. Eng., A 636, 551 (2015)
[14]	J. Kobayashi, D. Ina, N. Yoshikawa, K. Sugimoto, ISIJ Int. 52, 1894(2012)
[15]	H.S. Park, J.C. Han, N.S. Lim, J.B. Seol, C.G. Park, Mater. Sci. Eng., A 627, 262 (2015)
[16]	W.S. Li, H.Y. Gao, H. Nakashima, S. Hata, W.H. Tian, Mater. Charact. 118, 431(2016)
[17]	F.G. Caballero, C. García-Mateo, J. Chao, M.J. Santofimia, C. Capdevila, C.G. De Andrés, ISIJ Int. 48, 1256(2008)
[18]	K. Sugimoto, M. Misu, M. Kobayashi, H. Shirasawa, ISIJ Int. 33, 775(1993)
[19]	C. Wang, H. Ding, M. Cai, B. Rolfe, Mater. Sci. Eng., A 610, 65 (2014)
[20]	S. Kaar, D. Krizan, J. Schwabe, H. Hofmann, T. Hebesberger, C. Commenda, L. Samek, Mater. Sci. Eng., A 735, 475 (2018)
[21]	Q. Zhou, L. Qian, J. Tan, J. Meng, F. Zhang, Mater. Sci. Eng., A 578, 370 (2013)
[22]	H.Q. Huang, H.S. Di, N. Yan, J.C. Zhang, Y.G. Deng, R.D.K. Misra, J.P. Li, Acta Metall. Sin. (Engl. Lett.) 31, 503(2018)
[23]	S. Yan, X. Liu, W.J. Liu, T. Liang, B. Zhang, L. Liu, Y. Zhao, Mater. Sci. Eng., A 684, 261 (2017)
[24]	R. Tian, L. Li, B.C. De Cooman, X. Wei, P. Sun, J. Iron. Steel Res. Int. 13, 51(2006)
[25]	Y. Sakuma, D.K. Matlock, G. Krauss, Metall. Mater. Trans. A 23, 1221 (1992)
[26]	J. Chiang, J.D. Byod, A.K. Pilkey, Mater. Sci. Eng., A 638, 132 (2015)
[27]	K. Sugimoto, A. Kanda, R. Kikuchi, S. Hashimoto, T. Kashima, S. Ikeda, ISIJ Int. 42, 910(2002)
[28]	S.H. Sun, A.M. Zhao, R. Ding, X.G. Li, Acta Metall. Sin. (Engl. Lett.) 31, 216(2018)
[29]	J. Chen, M. Lv, S. Tang, Z. Liu, G. Wang, Mater. Charact. 106, 108(2015)
[30]	J. Wang, S. van Der Zwaag, Metall. Mater. Trans. A 32, 1527 (2001)
[31]	S.J. Lee, S. Lee, B.C. De Cooman, Scr. Mater. 64, 649(2011)
[32]	I.B. Timokhina, H. Beladi, X.Y. Xiong, Y. Adachi, P.D. Hodgson, Acta Mater. 59, 5511(2011)
[33]	X.C. Xiong, B. Chen, M.X. Huang, J.F. Wang, L. Wang, Scr. Mater. 68, 321(2013)
[34]	H. Luo, Scr. Mater. 66, 829(2012)
[35]	K. Sugimoto, B. Yu, Y. Mukai, S. Ikeda, ISIJ Int. 45, 1194(2005)
[36]	K. Zhu, C. Mager, M. Huang, J. Mater. Sci. Technol. 33, 1475(2017)