Effect of Nb Content on the Hot Deformation Behavior of S460ML Steel

doi:10.1007/s40195-018-0783-8

Abstract

Abstract:

The hot deformation behavior of S460ML steel with different Nb contents was investigated by single-pass compression experiment on the Gleeble-1500 thermo-machine simulator at deformation temperatures ranging from 900 to 1200 °C and strain rates from 0.1 to 5.0 s^-1. The critical strain of dynamic recrystallization (DRC) under different conditions was determined by using working hardening rate-strain curves. The relationship between critical strain and peak strain of DRC was discussed. By means of regression analysis method, the hot deformation activation energy of steels and the mathematical model for predicting DRC critical strain were calculated and established, respectively. The results showed that DRC occurred during hot deformation. As the deformation temperature increased and strain rate decreased, the critical strain of DRC decreased. The critical strain (ε_c) showed linear relationship with peak strain (ε_p). As Nb content increased, the needed deformation temperature for occurring DRC increased, while the needed strain rate for it decreased. The activation energy for hot deformation of S460ML steel increased with increasing Nb content.

Key words: Dynamic recrystallization, Critical strain, Nb content, Deformation temperature, Strain rate, Hot deformation

Yu-Cheng Zhang, Zhen-Sheng Meng, Yang Meng, Xin-Hua Ju, Zhong-Hang Jiang, Ze-Jun Ma. Effect of Nb Content on the Hot Deformation Behavior of S460ML Steel[J]. Acta Metallurgica Sinica (English Letters), 2019, 32(4): 526-534.

Figures/Tables 12

Table 1 Chemical composition of S460ML steel (mass fraction, %)

Steels	C	Si	Mn	P	S	Ni	Al	Mo?+?V+Ti	Nb
Nb-free	0.03-0.04	0.2-0.25	1.4-1.6	0.009	0.003	0.4-0.6	<?0.03	<?0.20	0
Low Nb	0.03-0.04	0.2-0.25	1.4-1.6	0.009	0.003	0.4-0.6	<?0.03	<?0.20	0.01-0.02
Medium Nb	0.03-0.04	0.2-0.25	1.4-1.6	0.009	0.003	0.4-0.6	<?0.03	<?0.20	0.03-0.04
High Nb	0.03-0.04	0.2-0.25	1.4-1.6	0.010	0.003	0.4-0.6	<?0.03	<?0.20	0.05-0.06

Fig. 1 True stress-strain curves of Nb-free steel at different conditions: a 0.1 s-1, b 0.5 s-1, c 1.0 s-1, d 3.5 s-1, e 5.0 s-1

Fig. 2 Experimental conditions for generating dynamic recrystallization for the steels with different Nb contents

Fig. 3 True stress-strain curve of Nb-free steel at strain rate of 0.1 s-1 and 1200 °C

Fig. 4 Curves of θ versus σa and dθ/dσ versus σb of Nb-free steel at 1200 °C with 0.1 s-1

Fig. 5 Metallographic morphologies of austenite grain of Nb-free steel under different strains: a 0.08, b 0.11, c 0.13, d 0.15, e 0.20, f 0.30

Fig. 6 Variation curves of critical strain for dynamic recrystallization with deformation temperature at strain rate of 0.1 s-1

Fig. 7 Variation curves of critical strain for dynamic recrystallization with strain rate at 1200 °C

Fig. 8 Relationship between peak stress and strain rate a, deformation temperature b for Nb-free steel

Fig. 9 Relationship between lnεc and lnZ for Nb-free steel

Fig. 10 Relationship between critical strain εc and peak strain εp for Nb-free steel

Table 2 Mathematical model for predicting critical strain of dynamic recrystallization for steels with different Nb contents

Steels	Z parameter model	Peak strain model
Nb-free	\(\varepsilon_{\text{c}} = 4.78 \times 10^{ - 3} \left( {\dot{\varepsilon }\exp \frac{34767}{T}} \right)^{0.165}\)	\(\varepsilon_{\text{c}} \approx 0.73\varepsilon_{\text{p}}\)
Low Nb	\(\varepsilon_{\text{c}} = 2.98 \times 10^{ - 3} \left( {\dot{\varepsilon }\exp \frac{35194}{T}} \right)^{0.178}\)	\(\varepsilon_{\text{c}} \approx 0.74\varepsilon_{\text{p}}\)
Medium Nb	\(\varepsilon_{\text{c}} = 1.74 \times 10^{ - 3} \left( {\dot{\varepsilon }\exp \frac{35893}{T}} \right)^{0.198}\)	\(\varepsilon_{\text{c}} \approx 0.73\varepsilon_{\text{p}}\)
High Nb	\(\varepsilon_{\text{c}} = 8.53 \times 10^{ - 3} \left( {\dot{\varepsilon }\exp \frac{41847}{T}} \right)^{0.115}\)	\(\varepsilon_{\text{c}} \approx 0.8\varepsilon_{\text{p}}\)

References

[1]	J. Dong, C. Li, C.X. Liu, Y. Huang, L.M. Yu, H.J. Li, Y.C. Liu, J. Mater. Res. 32, 3777(2017)
[2]	J. Dong, X.S. Zhou, Y.C. Liu, C. Li, C.X. Liu, H.J. Li, Mater. Sci. Eng. A 690, 283 (2017)
[3]	Z.Q. Wang, H. Zhang, C.H. Guo, W.B. Liu, Z.G. Yang, X.J. Sun, Z.Y. Zhang, F.C. Jiang, J. Mater. Sci. 51, 4996(2016)
[4]	R.J. Song, N. Fonstein, H.J. Jun, N. Pottore, D. Bhattacharya, S. Jansto, Metallogr. Microstruct. Anal. 3, 174(2014)
[5]	A. Pandit, A. Murugaiya, A.S. Podder, A. Haldar, D. Bhattacharjee, S. Chandra, R.K. Rayb, Scr. Mater. 53, 1309(2005)
[6]	H.J. Mcqueen, Encycl. Mater. Sci.Technol. 1, 2375(2001)
[7]	T. Furuhara, B. Poorganji, H. Abe, T. Maki, J. Miner. Metals. Mater. Soc. 59, 64(2007)
[8]	R.C. Souza, E.S. Silva, A.M.J. Jr, J.M. Cabrera,O. Balancin, Mater. Sci. Eng. A 582, 96 (2013)
[9]	E.J. Giordani, A.M. Jorge, O. Balancin, Scr. Mater. 55, 743(2006)
[10]	T. Chandra, I. Weiss, J.J. Jonas, Metal Sci.J. 16, 97(1982)
[11]	W.F. Shen, L.W. Zhang, C. Zhang, Y.F. Xu, X.H. Shi, J. Mater. Eng. Perform. 25, 2065 (2016)
[12]	D. Qian, Y. Peng, J. Mater. Eng. Perform. 24, 1906 (2015)
[13]	M.R. Barnett, G.L. Kelly, P.D. Hodgson, Scr. Mater. 43, 365(2000)
[14]	S. Solhjoo, Mater. Des. 54, 390(2014)
[15]	J.R. Cao, Z.D. Liu, S.C. Cheng, G. Yang, Acta Metall.Sin. 43, 35(2007). (in Chinese)
[16]	W.L. Gao, G.R. Bai, Z.M. Zhou, G. Luan, C. Long, Acta Metall. Sin. (Engl. Lett.) 6, 53(1993)
[17]	X.G. Zhou, Z.Y. Liu, D. Wu, Z. Li, C.M. Li, Acta Metall. Sin. (Engl. Lett.) 19, 385(2006)
[18]	W.C. Xu, X. Ma, F. Sun, Acta Metall. Sin. (Engl. Lett.) 2, 174(1989)
[19]	Y.H. Jiang, Y.K. Park, O.Y. Lee, Korean J. Mater. Res. 17, 634(2007)
[20]	B. Sander, D. Raabe, Mater. Sci. Eng. A 479, 236 (2008)
[21]	G.Y. Qiao, F.R. Xiao, X.B. Zhang, Y.B. Cao, B. Liao, Trans. Nonferrous Metals Soc. China 19, 1395 (2009)
[22]	D.T. Jiao, Q.W. Cai, H.B. Wu, J. Iron. Steel Res. Int. 17, 39(2010)
[23]	G.F. Zhou, M.B. Wen, P.H. Li, X.L. He, Acta Metall. Sin. (Engl. Lett.) 2, 623(2000)
[24]	K.B. Kang, O. Kwon, W.B. Le, Scr. Mater. 36, 1303(1997)
[25]	G.V. Prasad, M. Goerdelerm, G. Gottstein, Mater. Sci. Eng. A 400, 231 (2005)
[26]	A.D. Rollett, U.F. Kocks, Solid State Phenom. 35, 1(1993)
[27]	X.R. Lei, Q.F. Ding, Y.Y. Chen, X.L. Rui, S.R. Li, Q.F. Wang, J. Iron Steel Res. Int. 20, 38(2013)
[28]	C. Sanghyun, K.B. Kang, J.J. Jonas, ISIJ Int. 41, 766(2001)
[29]	A. Laasroui, J.J. Jonas, ISIJ Int. 32, 95(1991)
[30]	F.R. Xiao, B. Liao, Y.Y. Shan, G.Y. Qiao, Y. Zhong, C.L. Zhang, K. Yang, Mater. Sci. Eng. A 431, 41 (2006)
[31]	C.M. Sellars, W.J. Mctegart, Acta Metall. 14, 1136(1966)
[32]	S.L. Zhu, H.Z. Cao, J.S. Ye, W.H. Hu, G.Q. Zheng, J. Iron Steel Res. Int. 22, 264(2015)
[33]	C.M. Sellers, Mater. Sci. Technol. 6, 1072(1990)