FEM Analysis of Profile Control Capability during Rolling in a 6-High CVC Cold Rolling Mill

2014 ◽  
Vol 988 ◽  
pp. 257-262 ◽  
Author(s):  
Ke Zhi Linghu ◽  
Zheng Yi Jiang ◽  
Fei Li ◽  
Jing Wei Zhao ◽  
Meng Yu ◽  
...  

A 3D elastic-plastic finite element method (FEM) model of cold strip rolling for 6-high continuous variable crown (CVC) rolling mill was developed. The rolling force distributions were obtained by the internal iteration processes. The calculated error has been significantly reduced by the developed model. the absolute error between the simulated results and the actual values is obtained to be less than 10μm, and relative error is less than 1%. The developed model is significant in investigating the profile control capability of the CVC cold rolling mill in terms of work roll bending, intermediate roll bending and intermediate roll shifting.

2013 ◽  
Vol 773-774 ◽  
pp. 70-78 ◽  
Author(s):  
Abdulrahman Aljabri ◽  
Zheng Yi Jiang ◽  
Dong Bin Wei ◽  
Xiao Dong Wang ◽  
Hasan Tibar

Controlling cold strip profile is a difficult and significant problem has been found in industry during thin strip rolling. At present choosing the new type of strip rolling mill is the one of main methods to control the strip shape quality in cold rolling. The influences of rolling process parameters such as the work roll cross angle and work roll shifting on the strip shape and profile of thin strip are recognised throughout this study. The results show that the roll crossing and shifting is efficient way to control the strip shape. The increase of the work roll crossing angle would lead to improve the strip profile significantly by decreasing the exit strip crown and edge drop. The strip profile would be enhanced if the axial roll shifting was increased. Moreover, the total rolling force was analysed in detail by changing the roll cross angle and axial shifting roll.


Metals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1066
Author(s):  
Hao Tao ◽  
Hongbo Li ◽  
Jian Shao ◽  
Jie Zhang ◽  
Yujin Liu ◽  
...  

In order to analyze the flatness control characteristics for a certain UCMW (Universal Crown Mill with Work roll shifting) cold rolling mill, combined with the actual parameters in the field, a static simulation model of the quarter roll systems of the UCMW cold rolling mill was established by the ANSYS finite element software. The bearing roll gaps under the factors of the unit width rolling force, the roll bending force and the roll shift were calculated, which reflects the shape control characteristics and has a great influence on the friction and lubrication characteristics between the roll gaps. Additionally, the shape control strategy of the process parameters in the field was put forward. The results show that, at first, the work roll shift is the most effective shape control means, while the current-used range of the intermediate roll shift cannot make full use of the roll end contour of the intermediate roll, so the intermediate roll negative shift should be considered for shape control. At second, the excessive rolling force goes against the shape control, so the rolling force of each stand should be reasonably distributed. Finally, the shape control ability of the bending force is relatively weak, so the range of the work roll bending force should be appropriately increased.


Metals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 401
Author(s):  
Hainan He ◽  
Jian Shao ◽  
Xiaochen Wang ◽  
Quan Yang ◽  
Xiawei Feng

Due to the requirement of magnetic properties of silicon steel sheets, producing high-precision size strips is the main aim of the cold rolling industry. The tapered work roll shifting technique of the six-high cold rolling mill is effective in reducing the difference in transverse thickness of the strip edge, but the effective area is limited, especially for a high crown strip after the hot rolling process. The six-high mill with a small work roll size can produce a strip with higher strength and lower thickness under a smaller rolling load. At the same time, the profile of the strip can be substantially improved. By advancing a well-established analytical method, a series of simulation analyses are conducted to reveal the effectiveness of a small work roll radius for the strip profile in the six-high cold rolling process. Through the analysis of flattening deformation and deflection deformation on the load, the change rule of the strip profile produced by the work roll with a small roll diameter can be obtained. Combined with theoretical analysis and industrial experiments, it can be found that the improvement effect of the small work roll radius on the profile of the silicon strip is as significant.


2012 ◽  
Vol 25 (1) ◽  
pp. 122-127 ◽  
Author(s):  
Pengfei Wang ◽  
Dianhua Zhang ◽  
Xu Li ◽  
Jiawei Liu ◽  
Junsheng Wang

2012 ◽  
Vol 572 ◽  
pp. 55-60 ◽  
Author(s):  
Peng Liu ◽  
Hong Bo Li ◽  
Zhi Qian Shen

This paper focuses on a new type of 8-roll cold rolling mill with the back-up bearing roll. Compared to the traditional 6-roll cold rolling mill, a thick-walled bearing roll is used to multi-support the intermediate roll. By the rack, the fan-shaped gears, the eccentric core shaft and the servo-cylinder, the work roll can be pushed down by this screw down device on the top of the mill; By contrast with the 4(6)-roll mill, this type of mill has some characteristics, such as: the small size of rolls, lighter weight, the fast response for the screw down. The bearing roll is fixed by the supporting blocks placed on the rolling-mill housing. So this mill has large traverse rigidity, and this is propitious to the flatness control. By different means of strip flatness adjustments, such as the intermediate roll shifting, the roll bending and the bearing roll adjusting, the strip flatness can be well controlled. The oil-gas lubrication is used in the bearings of the bearing rolls, and the changing rolls equipment is designed for this type of mill too. A series of this type of mills (as 450, 800, 1250, 1450 series) have been produced since it was developed in 1997. The mills for 1250 and 1450 series have been applied in five-stand cold rolling mill and single stand reversing mill, a rolling speed of 800m/min has been achieved.


2017 ◽  
Vol 2017 ◽  
pp. 1-10
Author(s):  
Guangming Liu ◽  
Yugui Li ◽  
Qingxue Huang ◽  
Xia Yang ◽  
Aimin Liu

Dynamic characteristic analysis of a two-stand reversible cold rolling mill in the startup process was carried out. The delay algorithm of the interstand thickness was proposed. A new method combined with the accelerated secant and the tangent methods was established to solve the simultaneous equations. The thickness and interstand tension transition processes with different static tension establishing processes were analyzed. Both mills were operated under constant rolling force control mode in the above process. The results show that the strip thickness in the rolling gap reduces in the static mill screwdown process. The entry stand runs inversely to establish the static interstand tension. This area becomes an abnormal thickness reduction area of the incoming strip. It results in several abnormal interstand tension increases in the subsequent startup process. The tension increase leads to an impact force on the strip that is the main reason of the strip breakage in the startup process. So the static tension establishing process was optimized, and the interstand tension fluctuation and the strip breakage accidents both reduced significantly. The results are beneficial to the startup process of the two-stand reversible cold rolling mill.


2010 ◽  
Vol 145 ◽  
pp. 93-99 ◽  
Author(s):  
Dian Hua Zhang ◽  
Peng Fei Wang ◽  
Wen Xue Zhang ◽  
Xu Li

When there appeared catastrophic asymmetrical flatness defects in rolling processes, especially when the incoming strip is with a wedge shape, the tilting roll can hardly eliminate these defects completely. Moreover, the overshooting of tilting roll will lead to strip break. In order to improve the ability of cold rolling mill for asymmetrical flatness defects control, performance of the work roll asymmetrical bending as well as the intermediate roll asymmetrical bending has been analyzed, based on the actuator efficiency factors of them. In addition, for the purpose of obtaining accurate efficiency factors matrixes of actuators, a self-learning determination model of actuator efficiency factors was established in accordance with the practical rolling processes. In this paper, a 1250 single stand 6-H reversible UCM cold mill was taken as the object of this study, with efficiency factors of asymmetrical roll bending analyzed, which provides a theoretical basis for better flatness control. Analysis shows that the asymmetrical roll bending is significant for asymmetrical flatness control.


2011 ◽  
Vol 291-294 ◽  
pp. 601-605
Author(s):  
Jin Lan Bai ◽  
Jun Sheng Wang

In this paper, adaptive learning method of bending force presetting model in a six-high cold rolling mill is introduced. Adaptive learning coefficient of bending force presetting model is calculated by contrast between measured and model calculated actual bending force, then exponential method is used to modify the adaptive learning coefficient to improve the precision of the bending force presetting model. While calculating model calculated actual bending force, Legendre polynomials are used to convert measured flatness data to quadratic and quartic flatness coefficient, then regulating quantity on the quadratic flatness coefficient of intermediate roll bending force and work roll bending force is determined based on their regulate capability. Practical application shows that precision of the bending force presetting model has improved significantly by adaptive learning.


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