Simulation of type selection for 6-high cold tandem mill based on shape control ability

Abstract

A theoretical method for selecting strip rolling mill type that considered shape control ability was established using the figure alteration range that was worked by the alteration track of vector expressing strip’s cross section (crown) to express the shape control ability of rolling mill. With the mathematical models and simulation software that were developed by the authors’ own models, four types of mills were aimed, including HCM (6-high middle rolls shift type HC (high crown)-mill), HCMW (6-high middle rolls and work rolls shift type HC-mill), UCM (6-high middle rolls shift type HC-mill with middle roll bender) and UCMW (6-high middle rolls and work rolls shift type HC-mill with middle roll bender), and the shape and crown control ability of every mill type was analyzed and compared. An appropriate arrangement mode of tandem mill was brought forward. The results show that UCMW mill is a perfect choice for controlling shape and crown, and the area of control characteristics curve of UCMW (or UCM) is twice than that of HCM, but UCM mill is also a good choice for its simple frame. In other word, the shape and crown controlling ability of UCMW mill is better than that of UCM mill, but the frame of UCM mill is simpler than that of UCMW mill. As for the final type of mill, should be synthetically decided by thinking over fund and equipment technology.

Keywords

6-high mill / mill type selection / shape control / crown / simulation

References

[1] BALD W. Continuously variable crown (CVC) rolling[J]. Iron and Steel Eng, 1987 (3): 32–41.

[2] CHEN Jie, ZHONG Jue. Analytic model of loaded gap for CVC 4-high rolling mill[J]. Heavy Machinery, 1998(6): 42–44. (in Chinese)

[3] DONALD I R, SPOONER P D. The effects on strip quality due to rolling mill design[J]. Foreign Steel and Iron, 1989(3): 1–5. (in Chinese)

[4] RONNIE H. Experience Gained on the 5-stand cold rolling mill at SSAB with a 6-high stand using CVC technology[J]. MPT, 1990(1): 58–66.

[5] WangW.Theories and their Applications on Mill Types Selection and Parameters Optimization of Rolls System for Cold Strip Mill[D], 1999, Qinhuangdao, Yanshan University: 13-19

[6] WangG.-dong.Shape Control and Shape Theory[M], 1986, Changsha, Metallurgical Industry Press

[7] QiX.-dong.Study on Pass Schedule and Mill Types Selection for New Plate and Strip Mill in Baosteel[D], 2002, Qinhuangdao, Yanshan University

[8] PengY., LiuH.-min.. Study on increasing calculated precision and convergence speed of streamline strip element method[J]. Journal of Central South University of Technology, 2004, 11(1): 105-108

[9] LiuH.-m., ZhengZ.-z., PengY.. Computer simulation of the roll contact pressure characteristic for 6-High CVC wide strip mill[J]. Chinese Journal of Mechanical Engineering, 2000, 36(8): 69-73

[10] LiuH.-m., PengY., ChuY.-p., et al.. Strip element method for shape discrimination of strip rolling[J]. Communications in Numerical Methods in Engineering, 2004, 20(9): 709-720

[11] PengY., LiuH.-min.. A neural network recognition method of shape pattern[J]. Journal of Iron and Steel Research (International), 2001, 8(1): 16-20

[12] PengY., LiuH.-m., ZhangS.-g., et al.. Shape and profile control strategy for HC mill[J]. Iron and Steel, 2002, 37(4): 35-38

[13] PengY., LiuH.-m., HuJ.-p., et al.. Software for flatness analysis and presetting control of cold strip rolling and application[J]. Iron and Steel, 2003, 38(2): 34-37

[14] PengY.Theoretical Studies and Engineering Application of Shape Preset Control for HC Cold Mill Based on Strip Element Method[D], 2000, Qinhuangdao, Yanshan University