Effect of Hot Rolling Process Parameters on Microstructure Transformation and Microstructure of 45MnSiV Steel

Abstract:

The effects of final rolling temperature, cooling rate and deformation on phase transition point, the duration of the phase transition and the pearlite laminar layer of non-quenched and tempered steel 45MnSiV were studied by simulating the process of rolling and post-rolling cooling on Gleeble-3500 thermal simulator and thermal expansion tester. The results show that: the ferrite and pearlite transformation temperature ranges from 510 °C to 700 °C, and the bainite transformation temperature ranges from 400 °C to 500 °C when the steel is continuously cooled at a final rolling temperature of 950 °C, and the martensite transforming temperature is 300 °C under high cooling rate (> 10 °C/s); The pearlite laminar spacing decreases with the decrease of final rolling temperature. It can be seen that the rolling deformation increases the temperature at which the test steel undergoes a phase change at each cooling rate by comparing the results of deformation and no-deformation test at 950 °C. The effect of time advance on the phase transition zone of ferrite and pearlite is particularly obvious, but the effect on the phase transition temperature and time of the bainite and martensite phase transition is not obvious. When the final rolling temperature remains constant, the Rockwell hardness value of the test steel gradually increases, and the pearlite layer spacing decreases with the decrease of ferrite transformation temperature gradually and the increase of the cooling rate.

• Periodical: Materials Science Forum (Volume 944)
• Pages: 265-271
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.944.265
• Online since: January 2019
• Authors: Yun Long Wang, Yin Li Chen*, He Wei, Yi Na Zhao, Ze Sheng Liu
• Keywords: Final Rolling Temperature, Microstructure Transformation, Non-Quenched, Pearlitic Laminar Spacing, Tempered Steel

References

[1] S.H. Liu, X.H. Wang, G.W. Dai, et al. Investigation on non-metallic inclusions in hot forming steels of high cleanliness, Iron&Steel, 43(5) (2008) 35-39.

[2] Y.B. Chen, W. Ma, K. Jin, Development on improving the strength & toughness of microalloyed steels, Materials for Mechanical Engineering, 25(3) (2001) 1-6.

[3] C.F. Yan, Y.Z. Bao, H.R. Wang, et al. Application of non-quenched and tempered steel for semi-axle of heavy-duty vehicles, Hot Working Technology, (02) (2018) 3-8.

[4] H.Q. Zhang, Study on continuous cooling transformation diagrams of alloy steels, Wuhan: Wuhan University of Science and Technology, (2008).

[5] F.G. Caballero, H.K.D.H. Bhdaeshia, K.J.A. Mawella, et al. Design of novel high strength bainitic steels: Part1 Mater SciTechnol, 17(5) (2001) 512-516.

DOI: 10.1179/026708301101510348

[6] F.G. Caballero, H.K.D.H. Bhdaeshia, K.J.A Mawella, et al. Design of novel high strength bainitic steels: Part2 Mater SciTechnol, 17(5) (2001) 517-522.

DOI: 10.1179/026708301101510357

[7] X.N. Wang, G. Fang, Y. Li, et al. Resent progress of non-quenched and tempered steel for automotive sheet, Automobile Technology & Material, (09) (2014) 52-58.

[8] D. Yang, L.Q. Yang, Y.L. Sui, et al. Research on CCT curves of X80 pipeline girth weld, Welding Digest of Machinery Manufacturing, 12(3) (2016) 14-19.

[9] W.Y. Li, W.Y. Yang. Determination of CCT curves of one kind of air-cooling bainite steel, Science ＆ Technology of Baotou Steel (Group) Corporation, 42(5) (2016) 55-57, 86.

[10] T. Chen, A.M. Zhao, H.L. Fan, et al. Continuous cooling curve and phase transformation behavior of wear resistant steel 65Mn Cr, Transactions of Materials and Heat Treatment, 37(9) (2016) 144-150.

[11] J. Zhang, F.S. Liu, Z. Yu, Determination and analysis of CCT curves of bainite steel used in rail steel, Hot Working Technology, ,45(4) (2016) 84-86.

[12] G. Xu, W. Wang, X.Q. Zhang, CCT cures of metallic materials, Beijing: Chemical industry press, (2009).

[13] G.H. Xiao, F.M. Wang, C.R. Li, et al. Continuous cooling transformation of Nb-V-microalloyed high-strength hull steel, Journal of University of Science and Technology Beijing, (05) (2008) 495-500.

[14] W.X. Song, Metallographie, Beijing: Metallurgical Industry Press, (2007).

[15] H. Ding, Y.Z. Liu, L.F. Zhang, Effect of processing parameters on phase transition rules of high speed rolled wire of 60Si2MnA steel, Journal of University of Science and Technology Beijing, 23(1) (2001) 28-31.

[16] J. Li, F.Y. Sun, Effect of austenite deformation and cooling rate on the nucleation of γ→αtransformation, Journal of Iron and Steel Research, (01) (1988) 92-93.