Mechanics of Asymmetric Rolling of Thin Strip with Effect of Work Roll Edge Contact

2007 ◽  
Vol 561-565 ◽  
pp. 115-118
Author(s):  
Zheng Yi Jiang ◽  
Hai Bo Xie ◽  
L.M. Yang ◽  
Hong Tao Zhu ◽  
Dong Bin Wei ◽  
...  

Asymmetric rolling of thin strip has become important due to a significant decrease of rolling force, which contributes to obtain the extremely thin strip, to reduce the rolling passes, and to save the energy by a decrease of anneal treatment. In asymmetric rolling of thin strip, edges of work rolls may contact and deform when no or small work roll bending force is applied. Work roll edge contact forms a new deformation feature. In this paper, the effects of initial thickness of strip and friction coefficient on the rolling pressure, roll edge contact length and strip crown during asymmetric rolling of thin strip with work roll edge contact effect has been discussed, and the calculated rolling force with work roll edge contact is compared with the measured value.

2007 ◽  
Vol 340-341 ◽  
pp. 707-712 ◽  
Author(s):  
Zheng Yi Jiang ◽  
Hong Tao Zhu ◽  
Dong Bin Wei ◽  
A. Kiet Tieu

Asymmetric rolling is used to produce thinner strip, which can reduce rolling force significantly. When a thinner strip is rolled on a rolling mill, work roll edge may contact each other, which affects the mechanics of this special asymmetric rolling and the crown of the rolled strip. In this paper, the authors developed a numerical model to simulate this special rolling and obtained the rolling force, intermediate force, roll edge contact force, the crown of the rolled strip and the edge contact length. The effects of the initial thickness of strip and the friction variation at upper and lower work rolls on the rolling force and crown of the rolled strip are also discussed.


2014 ◽  
Vol 1061-1062 ◽  
pp. 515-521 ◽  
Author(s):  
Abdulrahman Aljabri ◽  
Zheng Yi Jiang ◽  
Dong Bin Wei

Cold rolled thin strip has received a great deal of attention through technological and theoretical progress in the rolling process, as well as from researchers who have focused on some essential parameters of strip such as its shape and profile. This paper describes the development of a 3-D finite element model of the shape of thin strip during cold rolling to simulate the cold rolling of WCS (work roll crossing and shifting) in asymmetric rolling. This finite element model considers the asymmetrical rolling parameters such as variations in the diameters of the rolls and the crossing angle as the work roll shifts on the strip during cold rolling. The shape and profile of the strip are discussed in the asymmetrical and symmetrical rolling conditions, while the total rolling force and distribution of stress are discussed in the case where the roll cross angle and axial shifting roll changes. The results can then be used to control the shape and profile of thin strip during rolling.


1970 ◽  
Vol 92 (2) ◽  
pp. 453-459 ◽  
Author(s):  
H. A. Kuhn ◽  
A. S. Weinstein

A method is presented for the determination of the lateral distribution of pressure in thin strip rolling. A simplified three-dimensional analysis of elastic deformation of the rolls is developed for use in the method. Pressure in the roll edge contact regions (in underface rolling), as well as in the roll-strip contact region, is considered. In the case of four-high, planetary, and Sendzimir-type mills, the lateral distribution of pressure between the work roll and backup rolls is also found. Calculated results indicate lateral pressure distributions which have peak values at each edge of the strip with a minimum at the center. The degree of this nonuniformity depends on roll geometry and configuration. Partition of the total rolling force between roll-strip contact and roll edge contact in underface rolling is also determined. Since interroll heat transfer is dependent on contact area, and hence, pressure, the results can also aid the determination of lateral temperature distributions in the rolls. In addition, the method is potentially useful for a study of the influence of roll geometry and configuration on strip shape.


2007 ◽  
pp. 115-118
Author(s):  
Zheng Yi Jiang ◽  
H.B. Xie ◽  
L.M. Yang ◽  
Hong Tao Zhu ◽  
Dong Bin Wei ◽  
...  

2008 ◽  
Vol 22 (31n32) ◽  
pp. 5728-5733
Author(s):  
Z.Y. JIANG ◽  
D.W. WEI ◽  
A.K. TIEU

An influence function method has been developed to simulate the asymmetric cold rolling of thin strip with work roll kiss at edges. The numerical simulation model was obtained based on the deformation compatibility of the roll system in rolling and lateral directions. The strip plastic deformation has been considered in the formulation, which is significantly different from the traditional theory of metal rolling. The rolling mechanics and crown of the strip with work roll edge kiss, which are new findings for cold rolling of thin strip, are obtained. A comparison of the rolling force, roll edge kiss force and the strip crown after rolling has been conducted for various cross shear regions in the roll bite. Results show that the calculated strip crown is in good agreement with Ameasured value, and the rolling force and strip crown decrease with an increase of cross shear regions, as well as the work roll edge kiss force and edge wear decrease. The friction also has an influence on the profile of the rolled thin strip.


2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Hasan Tibar ◽  
Zhengyi Jiang

The optimization of rolling parameters in order to achieve better strip shape and to reduce rolling force is a challenge in rolling practice. In this paper, thin strip asymmetrical rolling of aluminum at various speed ratios under lubricated condition has been investigated at various combinations of work rolls cross (WRC) angles and work rolls shifting (WRS) values. The effects of strip width, reduction, and rolling speed on strip shape taking WRC and WRS into consideration are discussed. Results show that strip profile improves significantly when the WRC angle is increased from 0° to 1°, with an associated reduction in rolling force. Increasing WRS value from 0 to 8 mm improves the strip profile as well but not as significantly as when WRC angle is increased. No significant improvement was found in strip shape when the strip width was increased. At higher reduction, the strip shape was improved; a decrease in the rolling force was also observed. A higher speed ratio was found to be effective only at a higher WRC angle. The effect of lubrication on the strip profile was significant. Results indicate that an optimum combination of WRC, WRS, reduction, width, and speed ratio under lubricated conditions can ensure an improved exit strip profile, reduce rolling force, and obtain a better quality strip.


2015 ◽  
Vol 29 (10n11) ◽  
pp. 1540032 ◽  
Author(s):  
Abdulrahman Aljabri ◽  
Zhengyi Jiang ◽  
Dongbin Wei

In order to analyze the effects of cold rolling parameters such as the crossing angle and axial shifting value of work rolls on the strip profile, extensive tests were carried out on a 4-high rolling mill equipped with a work roll crossing and shifting system. The results show that the strip profile is nearly flat under asymmetrical rolling. The rolling force was also analyzed in detail by changing the crossing angle and axial shifting value of work rolls.


2014 ◽  
Vol 989-994 ◽  
pp. 3386-3389
Author(s):  
Zhu Wen Yan ◽  
Hen An Bu ◽  
Dian Hua Zhang ◽  
Jie Sun

The influence on the shape of the strip from rolling force fluctuations has been analyzed. The combination of intermediate roll bending and work roll bending has been adopted. The principle of rolling force feed-forward control has been analyzed. The feed-forward control model has been established on the basis of neural networks. The model has been successfully applied to a rolling mill and a good effect has been achieved.


2004 ◽  
Vol 155-156 ◽  
pp. 1280-1285 ◽  
Author(s):  
Z.Y. Jiang ◽  
H.T. Zhu ◽  
A.K. Tieu ◽  
W.H. Sun

2016 ◽  
Vol 854 ◽  
pp. 93-98
Author(s):  
Kai Köhler ◽  
Norbert Kwiaton ◽  
Martin Bretschneider

Applying a specific roughness on steel sheets, to ensure paintability and sufficient lubrication, is a crucial point for the metal forming processes. Due to the strength of high manganese HSD® steels (X70MnAlSi 15-2.5-2.5), special actions are necessary to obtain the required roughness. At Salzgitter Mannesmann Forschung GmbH skin-pass rolling experiments on high manganese HSD® steels with different PRETEX® textured work-rolls were performed to investigate the influence of roll-surface-texture and skin-pass rolling force on the roughness transfer. The roughness and texture parameters of the steel sheets and roll surfaces were determined using optical confocal microscopy measurements. It is clearly shown that the work-roll surface texture has a major influence on the roughness transfer from work-rolls to steel sheet surfaces.


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