• Transactions of Materials Processing
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• v.21 no.7
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• pp.426-431
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• 2012

The work roll of a Sendzimir mill has a small diameter in comparison to its length, so it is easily deformed by the rolling pressure. It also has a complex back up roll system, so it is difficult to analyze the roll deformation. For this reason in Part I we have developed a model which predicts the radial displacement of the roll. In this paper, we apply the model to a Sendzimir mill and propose a new model for the prediction of the deformed roll profile in a Sendzimir mill. The prediction accuracy of the new model is demonstrated through comparison of the predictions from the FE model.

• Transactions of the Korean Society of Mechanical Engineers
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• v.14 no.6
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• pp.1689-1699
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• 1990

Sendzimir rolling mill is widely used for rolling hard materials such as stainless steel due to its small work roll diameter and shape controllability using two effective actuators, AS-U-Roll crown adjustment and lst. intermediate roll shifting. However, in comparison with 4-high or 6-high mills, it is noteasy to get good strip or excellent flatness because Z-mill has small diameter of work rolls which are easily deformed by load. A new mathematical model based on the method of dividing roll and strip into multo-portions was used to develop strip profile prediction software. Using the developed software, several influencing factors related to rolled strip profile for Z-Mill were tested analytically and characterized for the effective shape control. The effects of adjusting shape control actuators of Z-Mill on strip profile were also examined and discussed in detail.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2009.04a
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• pp.19-22
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• 2009

It is essential to predict the deformed roll profile for the prediction of the strip profile in rolling process. The work roll of the Sendzimir mill has a small diameter in comparison to a barrel length, so that it is well deformed by the rolling pressure. Also it has a complex roll system, so it is difficult to analyze the roll deflection. In this paper, 3D finite element method is used for the analysis of the roll deflection of the Sendzimir due to the contact between rolls. But it takes much time to get the results, so that the on-line model to evaluate the radial deformation of a roll is developed on the basis of the finite element method.

• Journal of Institute of Control, Robotics and Systems
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• v.15 no.10
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• pp.1062-1070
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• 2009

The strip shape for the stainless steel process has made an issue of the strip quality, and hence the shape control method is developed at the Sendzimir rolling mill (ZRM). ZRM is a stainless cold rolling mill and has actuators for the shape control. They are first intermediate rolls and top crown rolls, which are controlled horizontally and vertically, respectively. The shape control of the stainless steel rolling process has difficulty in obtaining the symmetrical shape. The objective of the shape control is to minimize the shape deviation and to maintain stable state, which keeps symmetrical shape pattern in the lateral direction. The method of the shape recognition employs a least squares method and neural network. The shape deviation is the difference between the target shape and actual shape and is controlled by the fuzzy shape control. The fuzzy shape control using operator's informative knowledge is proposed in this paper. The experiments are carried out online for various stainless materials and sizes. The productivity of the rolling process has increased from 9.0 to 9.4 tons per hour.

• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.2
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• pp.257-266
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• 1993

Computer Simulation based of divided element method was done to predict strip shape in20-high Sendzimir Mill and has been used to find a way for preventing quarter waves occurring in the wide and thin gaged strip rolling. The simulation showed that it was difficult to prevent quarter waves by the existing methods of controlling actuators such as the shifting of the first intermediate roll and the profile control of As-U-Roll in back up roll. It was, however, confirmed analytically and experimentally that quarter waves could be effectively reduce by changing taper mode at the barrel-end taper radius of the first intermediate roll.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.180-180
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• 2000

The shape of cold strip for the stainless process has been become issue in quality recently, and hence POSCO (Pohang Iron & Steel Co., Ltd) developed an automatic control system for strip shape in the sendzimir mill. The strip shape is measured by an outward measuring roll and is controlled by As_U roll and first intermediate roll. As_U roll consists of 8 saddles, which are controlled vertically. The fist intermediate rolls, which are controlled horizontally, consist of two pairs of rolls up and down. A developed shape control system is applied to real plant by using fuzzy logic and neural network method to control actuators; As_U roll and first intermediate roll. This system composes mainly of three parts as a real-time system, input to output conditioner board, and man-machine interface. The actual shape is recognized by neural network and converted into symmetric shape. The fuzzy controller, based on the shape from neural network and sensor, controls positions of the As_U roll and first intermediate roll. This paper verifies the shape controller performance. The experiments are made on line for the sendzimir mill. The shape control performance shows very efficient for the target tracking, shape symmetry, and fluctuation of shape.

• Journal of Power System Engineering
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• v.15 no.5
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• pp.83-90
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• 2011

In general, 20-high Sendzimir mills(ZRM) use small diameter work rolls to provide massive rolling force. Because of small diameter of work rolls, steel strip has a complex shape mixed with quarter, edge and center waves. Especially when the shape of the strip is controlled automatically, the actuator saturation occurs. These problems affect the productivity and quality of products. In this paper, the problems in automatic shape control of ZRM were analyzed. In order to evaluate the problems for the automatic shape control in ZRM, recognition performance was analyzed by comparing the measured shape and the recognized shape. The actuator positions by the shape recognition and the manual operation were compared. From the analysis results, the necessity of the improvement of recognition performance in ZRM is suggested.