Effect of Ferritic Hot Rolling Process on Microstructure and Properties of IF Steel

Abstract:

The effect of ferritic hot rolling process on microstructure and properties of Ti microalloyed IF steel was investigated. The hot rolling-coiling, cold rolling and continuous annealing processes of ferritic zone were physically simulated. The influence of thermal deformation (finishing rolling temperature, coiling temperature) on the structure, texture and forming properties of Ti-If steel was studied through tensile test, EBSD, XRD and other analytical methods. The results showed that the recrystallization occurred after hot rolling and coiling in the ferritic region. Weak α-fiber and weak γ-fiber were obtained in the central layer of hot rolling plates, and the strength of γ-fiber was higher when finished rolling at low temperature. α-fiber and weak γ-fiber were strengthened after cold rolling. After annealing, the α-fiber was weakened and the γ-fiber was strengthened, and the γ-fiber became the main texture. The larger and more uniform grain size and better mechanical properties were obtained by IF steel finished rolling and coiling at high temperature and after continuous annealing, reaching yield strength of 106 MPa, tensile strength of 297 MPa, elongation rate of 52%, n value of 0.26 and r value of 2.3. The hot rolling texture is hereditary. If the more γ-fiber is formed after hot rolling, the more γ-fiber recrystallization texture is formed after cold rolling and annealing.

• Periodical: Materials Science Forum (Volume 993)
• Pages: 505-512
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.993.505
• Online since: May 2020
• Authors: Wen Gao Chang, Wei Yu*, Huan Yang, Zeng Qiang Man, Yun Fei Cao
• Keywords: Ferritic Hot Rolling, Formability, IF Steel, Microstructure, Texture

References

[1] Guo Xiaolong, Zheng Zhiwang, Sun Lijun, Process technology and development situation of extra-deep drawing IF steel, J. Shanghai Metals. (2008) 39-43.

[2] Cui Deli, Wang Xianjin, Jin Shantong, History and Development of Extra Low Carbon Steel, J. Research on Iron & Steel. (1994) 38-46.

[3] W. C. Jeong,Effect of hot-rolling temperature on microstructure and texture of an ultra-low carbon Ti-interstitial-free steel, J. Materials Letters 62 (2008) 91-94.

DOI: 10.1016/j.matlet.2007.04.081

[4] Zuo Jia, Recrystallization Rule Research on Ferrite Rolling of Containing Ti-IF Steel, D. North China University of Science and Technology. (2015).

[5] Zheng Zhiwang, Chen Jie, Zhou Dan, Effect of Coiling Temperature on Evolution of Microstructure and Texture During Annealing, J. Iron Steel Vanadium Titanium. (2007) 1-8.

[6] Li Sijun, Qu Jiahui, Wang Fu, et al, Texture Formation of IF Steel Sheet Hot-Rolled in Ferrite Region and Its Transformation During Cold-Rolling and Annealing, J. Journal of Northeastern University (Natural Science). (2007) 345-348.

[7] Y. Liu, J. Sun, L. Zhou, Y. Tu, F. Xing, Y. Guo, Q. Tong, Experiment investigation of deep-drawing sheet texture evolution, J. Journal of Materials Processing Technology. 140 (2003) 509-513.

DOI: 10.1016/s0924-0136(03)00787-8

[8] Yu Fengyun, Wang Yinong, Jiang Qiwu, Formation Mechanism of {111} Recrystallization Terture in IF Steel, J. Materials Science & Technology. (2008) 724-727.

[9] Y. Guo, Z. Wang, G. Wang, Texture Evolution During Annealing in Warm-Rolled and Cold-Rolled Ti-IF Steel, J. Journal of Materials Engineering and Performance 20 (2011) 417-421.

DOI: 10.1007/s11665-010-9690-5

[10] GAO Lufeng, KANG Yonglin, LV Chao, et al, Experimental Study on Recrystallization Texture of Ti-IF Steel During Annealing, J. Material & Heat Treatment. (2010) 45-48.