• KSTLE International Journal
• /
• 제2권1호
• /
• pp.80-84
• /
• 2001

The purpose of this paper is to show the result from the study to improve the formability and appearance which is important in the cold rolled strip, the coated strip and prepainted strip. Furthermore, to give appropriate surface roughness, shape of work roll for temper mill is also important. The strip has a greater peak counts and homogeneous roughness. This makes the prepainted surface smooth and consistent in appearance with good image clarity. Therefore, the surface roughness of the work roll is very important. The reason that surface roughness of the work roll is transferred to the strip surface is the rolling farce and tension at the temper rolling or cold rolling. This study is classified in order to get an accurate and homogeneous roughness. There are few papers published in this field, because its importance is not known and the proper operation of the machine is not generally well known. This paper investigates the correlation between strip surface roughness and the surface of the work roll. After studying the surface roughness and shape according to the texturing method for roll surfaces at temper rolling, the findings were as follows. Irregular surface roughness can be compensated with several paint coatings, but this also makes the quality deteriorate and manufacturing costs go up.

• Journal of Mechanical Science and Technology
• /
• 제18권7호
• /
• pp.1074-1085
• /
• 2004

There are many intermediate web guides in cold rolling mills process such as CRM (cold rolling mill), CGL (continuous galvanizing line), EGL (electrical galvanizing line) and so on. The main functions of the web guides are to adjust the center line of the web (strip) to the center line of the steel process. So they are called CPC (center position control). Rapid process speed cause large deviation between the center position of the strip and the process line. Too much deviation is not desirable. So the difference between the center position of the strip and the process line should be compensated. In general, the center position control of the web is obtained by the hydraulic driver and electrical controller. In this paper, we propose modelling and several controller designs for web-guide systems. We model the web and guide by using geometrical relations of the guide ignored the mass and stiffness of the web. To control the systems, we propose PID controllers with their gains tuned by the Ziegler-Nichols method, the H$\_$$\infty$/ controller model-matching method, and the coefficient diagram method (CDM). CDM is modified for high order systems. The results are verified by computer simulations.

• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 2003년도 추계학술대회논문집
• /
• pp.156-158
• /
• 2003

Sheets of aluminum alloy 1050 were asymmetrically cold rolled in a rolling mill with different roll speeds. In order to promote the shear deformation during asymmetrical rolling, cold rolling without lubrication was performed. The variation of the shear strain state during asymmetrical rolling was tackled by means of FEM calculations. Asymmetrical rolling gave rise to the development of pronounced residual shear strain gradients throughout the thickness layers.

• 제어로봇시스템학회논문지
• /
• 제2권3호
• /
• pp.134-141
• /
• 1996

In this paper, we formulate the mathematical model for a single-stand rolling mill and design control systems for the thickness control at the exit of roll stand and for the tension control of the strip in the process. We propose a thickness controller based on the Internal Model Control structure which can be an effective application when the frequency components of the thickness deviation of the entry strip are known and, show how it can be appropriately combined with BISRA AGC method for a precise thickness control while maintaining the robustness against the modeling error of the mill modulus. It is illustrated by simulations that the proposed thickness control method gives better performance than existing methods and has the robustness against the modeling error of the mill modulus as well.

• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 1998년도 춘계학술대회논문집
• /
• pp.130-133
• /
• 1998

An integrated finite element computer simulator is presented for the prediction of three dimensional heat transfer and metal flow occurring in the strip, and heat transfer and thermo elastic phenomena occurring in the rolls in 4 high mill hot strip rolling. Basic finite element models are described, with emphasis on combining each model to deal rigorously with the coupled aspect of the thermo-mechanical behaviors of the rols and strip through an iterative solution procedure. A series of process simulation are carried out to investigate the effect of various parameters under the actual process conditions. The results are shown and discussed.

• 대한기계학회논문집
• /
• 제15권1호
• /
• pp.376-385
• /
• 1991

본 연구에서는 그루브의 각도에 따라 그루브 에징을 한 형상과 상사하게 가상 의 슬라브를 제작하여 오버랩에 영향을 미치는 압연인자들을 분석하고 그 영향을 검토 함으로써 최적 G 롤의 각도를 결정하였고, 최적인 G 롤의 형상으로 에저를 제작하여 G 에징량에 따른 오버랩량의 변화를 고찰하였다.

• 소성∙가공
• /
• 제10권2호
• /
• pp.130-136
• /
• 2001

The mathematical set-up model was developed to reduce the mechanical property deviation in annealed and slightly rolled steel strip. The mechanical peculiarities of skin pass rolling process, such as high friction value and non-circular contact arc, low reduction and non-negligible entry and exit elastic zones as well as central restricted deformation zone are all taken into account. The deformation of work rolls is calculated with the influence function method and arbitrary contact arc shape is permitted. The strip deformation is modeled by slab method and the entry and exit elastic deformation zones are included. The strip restricted deformation zone near the neutral point is also considered. It was revealed that the new model has better accuracy than present regression model by statistical analysis with actual mill rolling data.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
• /
• pp.374-374
• /
• 2000

In this paper, we developed an ANFIS controller through ES algorithm for disturbances rejection in Hot Rolling. The looper of a Hot Rolling is installed between each pair of stands and plays key roles to enhance the product quality of the strip by controlling the tension and the width of the strip. At the same time, the AGC on top of the Mill produces a strip with the desired thickness through pressing its Mill. Between both, however, interactions are caused by coupling effects among strip tension, looper angle and strip thickness. In addition, in case disturbances, it is more difficult to keep strip quantities desirable. So we present an ANFIS controller through ES algorithm which is able to identify fuzzy rule with input/output data and update itself through output errors.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
• /
• pp.132-132
• /
• 2000

The reliability of EIC systems in hot rolling mill is indispensable and very important in order to maintain stable production. Signals obtained from sensors and control system should be analyzed to monitor the condition of down coiler in hot rolling mill. We develope a monitoring system of down coiler which is composed of three parts (1) data acquisition and MMI (2) signal processing and analyzing, and (3) automatic data saving. Also it is designed to enable to inform users the abnormal conditions of down coiler. This developed system is expected to make it possible to reduce long downtime, secure high facility precision, and maintain high control levels.

• 한국공작기계학회:학술대회논문집
• /
• 한국공작기계학회 2002년도 추계학술대회 논문집
• /
• pp.41-46
• /
• 2002

In the face of global competition, the requirements fer the continuously increasing productivity, flexibility and quality (dimensional accuracy, mechanical properties and surface properties) have imposed a major change on steel manufacturing industries. The automation of hot rolling process requires the developments of several mathematical models for simulation and quantitative description of the industrial operations involved. To achieve this objectives, a new loaming method with neural network to improve the accuracy of rolling force prediction in hot rolling mill is developed. Also, Genetic Algorithm(GA) is applied to select the optimal structure of the neural network and compared with that of engineers experience. It is shown from this research that both structure selection methods can lead to similar results.