Papers by Keyword: Edge Drop

Abstract: Edge-drop control enlarges the shape control theories and technologies. But compared to the profile and flatness control technology, the edge drop control is a developing topic. This paper analyze the influence of strip thickness, strip width, reduction ratio, friction coefficient and deformation resistance on the edge drop based on the elastic deformation of rolls and the three-dimensional plastic deformation of strip for UCMW cold rolling mill. The results will support the further research on the edge drop control for cold rolling mill.

Abstract: The HOFC (High Order Flatness Control) work roll curve was designed using Matlab. It has great flatness control ability, for the roll diameter in the position of the 1/4 roll length can be altered with the changing of angle and index parameters. Combined with the data from a hot strip factory, the elastic deformation of the HOFC work roll was analyzed following the influence coefficient method. The distribution curves of the exit thickness, roll force, work roll bending, pressure between rolls, roll flatting, and roll gap geometry were given under the conditions of different roll parameters. Results show that the HOFC work roll curve can eliminate the high flatness defects, reduce the edge drop, improve the lateral thickness uniformity, and maximize the available cross section of the strip effectively.

Abstract: Transverse thickness difference is a key index of plate shape for electrical steel product. This paper analyzed and optimized original automatic control system for transverse thickness difference of MH UCMW rolling mill. By adding Multi-points assessment in edge drop region, steep drop width is reduced, and system yield is improved; By optimizing rigid control strategy into flexible control strategy, using three stands control instead of two stands, and rationally allocating each stand load for edge drop control, transverse thickness difference quality level is improved, and rolling stability is promoted. Based on control system optimization, control ability for transverse thickness difference is significantly improved, head-tail ultra gauge length is shortened from 110 meter to 50 meter, and transverse thickness difference high-quality ratio is improved from 35% to 87%.

Abstract: Edge Drop Control is the weak point although it enriches the contents of the shape control in cold tandem rolling mill. In this paper, the existing edge drop control strategy is analyzed and the edge drop control strategy optimization is researched. The simulation results show that the optimized control system can effectively control the edge drop.

Abstract: The flatness and edge drop control system is a coupled multivariable control system. Realizing the coupling relationship quantitative analysis and decoupling control of them is one of the most important parts of achieving the high-precision control. In this paper, the flatness and edge drop control abilities of all the control actuators are analyzed. The coupling relationship between flatness and edge drop is analyzed. The decoupling control method is proposed to realize the decoupling control of flatness and edge drop. Simulation results represent that the flatness and edge drop control performance is improved effectively.

Abstract: Edge drop of strip and sheet is a key technological issue besides of gauge control and shape control during the process of wide strip rolling, the reasonable control procedure of edge drop can increase the qualified product ratio, as well the quality and performance of product, it is especially effective for the silicon steel sheet, tin sheet and automobile body sheet. Therefore, more researchers focus on the edge drop of strip and its control technology in recent years. In this paper, a new strip profile control equation is established originally, according to the ways of strip shape control technology of large-scale tandem cold rolling mills. The new equation describes both the shape control and edge drop control. Some verification is developed in the equation based on the 1420mm UCMW tandem cold mill. The research result about mechanics of edge drop and it's control have been applied in tandem cold rolling mill. The good result is obtained according to the field measured data, and the control precision is increased greatly.

Abstract: The edge drop of steel strip is an important factor in determining the quality of rolled products. Edge drop control system used on 1420 mm cold tandem mill is introduced, which was developed by BAOSTEEL. Edge drop control system went into operation in December 2011. Now system works normally at all times and gives better control performance for the edge drop.

Abstract: K-WRS technology has a better edge drop control effect in cold tandem rolling mill, but it still exists some problems such as contact pressure peak beyond the limit, transition peak and the uneven distribution of contact pressure between the rolls in practical application. In this paper, tapered work roll shape is designed and optimized. The simulation analysis shows that the optimized roll shape not only can effectively control the edge drop of strip，but also can improve the contact pressure between the rolls. At the same time, it also can reduce the influence on the flatness control from the edge drop control.

Abstract: Realizing the decoupling control of them is one of the most important issues to achieve the flatness and edge drop high-precision control. In this paper, the flatness and edge drop control capabilities of all the control actuators are analyzed. The coupling relation of flatness and edge drop is analyzed. The neural network inverse decoupling control method is proposed to realize the decoupling control of flatness and edge drop. Simulation results represent that the flatness and edge drop control performance is improved effectively.

Abstract: The taper work roll of the 1700 mm tandem cold rolling mills had some problems in the course of using, and the taper roll contour was ground difficultly and the difference between the designed contour and grinding contour was very big, and the work roll and backup roll had very serious and non-uniform roll wearing and even often had roll spalling, and above those problems affected the stability of rolling process seriously. After analyzing the structure and contour of the taper work roll, it was found that the work roll contour was designed unreasonably and the straight line part and the edge drop control part of roll contours were not connected smoothly, and so it lead to the local stress concentration easily in the transition region and a bigger contacting pressure peak between work roll and backup roll appeared. On basis of decreasing the contacting pressure peak and taking the width of rolled strip and the grinding contour length change into consideration, the design method of the edge control contour part of the taper roll was put forward. The finite element model was built with the software ANASYS9.0 to analyze the mill shape adjusting characteristics, and the simulation result showed that the newly-designed taper roll contour could improve the mill shape adjusting ability. It was shown in the rolling trial that the strip edge drop average was decreased from 14.9μm to 7.5μm and the edge drop fluctuation of strip was restrained to some extent and controlled within ±3μm.