• Proceedings of the KSME Conference
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• 2007.05a
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• pp.544-548
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• 2007

In general, final width of hot strip should be accomplished in this stage because width reduction of strip hardly appears during typical finishing mill. However, it is difficult to control the width of strip in the roughing mill process as the horizontal rolling of strip is subsequently performed after the vertical rolling. It is therefore important to obtain the deformation rolling direction on strip width to minimize the width spread of strip during horizontal rolling after vertical rolling. Generally there is Sizing press type and Edger-roll type. The width reduction process in sizing press has small amount of width spread compared with the edger. However, productivity by the sizing press process is much lower than those of the edger. In this study, sizing press and Edger-roll process parameters in a sheet rolling mill were set at specified values and the effect of the change in these parameters on product quality and process performance were evaluated.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1997.10a
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• pp.161-166
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• 1997

Application of hot roiling oil lubrication technology was broadened to the field of RM stands of Hot Rolling Mill at Pohang works. The primary object was to improve the quality of the strip sttrface and the rolls by oil lubrication in hot rolling process. Prior to the actual field application preliminary test was conducted to evaluate the effect of hot rolling oil lubrication at RM stands. From the test, it has been found that the use of oil lubrication tends to prevent the progression of the heat cracks and thereby increases the quality of the strip surface and the wear life of the rolls. New hot rolling oil lubrication system was applied to the RM stands VSB, R1, R2, R3, R4 and edger rolls. With the introduction of a rolling lubricant, the quality of the strip surface and rolls was improved and overall roll dressing has decreased. Also there has been a improvement of productivity from the long roll life.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1999.08a
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• pp.447-451
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• 1999

The plate crown and shape control of plate rolling has become important to obtain not only improved quality but also better yield of products and higher work ratio of rolling. Therefore, the development of a new plate crown and shape control system has been demanded in plate rolling mill. The 3rd Plate Rolling Works of POSCO introduced the new unique system

• Journal of the Korea Institute of Information and Communication Engineering
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• v.4 no.5
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• pp.951-961
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• 2000

A diagnosis system that provides early warnings regarding machine malfunction is very important for rolling mill so as to avoid great losses resulting from unexpected shutdown of the production line. But it is very difficult to provide early warnings in rolling mill. Because dynamics of rolling mill is non-linear. This Paper proposes a new method for diagnosis of rolling mill using wavelet transform(W) to solve this problem. Proposed method that measures the vibration signals of rolling mill on-line and analyze it using wavelet to acquire pattern data. And we design a fault-diagnosis system that diagnose a rolling mill using this data. Validity of the new method is asserted by real numerical data experiment.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.21 no.7
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• pp.1030-1041
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• 1997

The control model in the tandem cold rolling mill consists of many mathematical theories and is used to calculate the reference values such as the roll gap and the rolling speed for good operation of rolling mill. But, the control model used presently has a problem causing inaccurate prediction of the rolling force. By the parameter identification, it was found that the main factor causing inaccurate prediction of the rolling force was incorrect modeling of the friction coefficient and the flow stress. To get rid of the erroneous factor new adaptive schemes are suggested in this work. Those are a long-time adaptation by the iterative least-square method and a short-time adaptation by the recursive weighted least-square method respectively. The new equations for the friction coefficient and the flow stress are derived by applying the suggested adaptive algorithms. Through the on-line test in an actual mill, it is proved that the rolling force predicted by the new equations is more accurate than the one by the existing equations ever used.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2000.10a
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• pp.13-16
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• 2000

In the hot strip mill, a bad threading and shape of strip strip in the finishing mill was caused by asymmetric rolling In roughing min. Mathematical analysis for camber control of roughing mill in hot strip rolling has been developed. Each equation in the camber control model was derived from geometrical characteristics of camber mechanism. The model can predict variables such as wedge, side slippage and roll force difference etc. from a measured camber value and then find an optimum roll gap condition for minimizing camber in the next pass.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.1083-1086
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• 1996

Cold rolling mill process in steel works uses stands of rolls to flatten a strip to a desired thickness. At cold rolling mill process, precalculation determines the mill settings before a strip actually enters the mill and is done by an outdated mathematical model. A corrective neural network model is proposed to improve the accuracy of the roll force prediction. Additional variables to be fed to the network include the chemical composition of the coil, its coiling temperature and the aggregated amount of processed strips of each roll. The network was trained using a standard backpropagation with 4,944 process data collected from no.1 cold rolling mill process from March 1995 through December 1995, then was tested on the unseen 1,586 data from Jan 1996 through April 1996. The combined model reduced the prediction error by 32.8% on average.

• Journal of Advanced Marine Engineering and Technology
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• v.34 no.2
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• pp.303-309
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• 2010

Copper tube rolling process using the planetary rolling mill has been studied by using finite element method. This rolling is process that makes copper tube by three-roll with mannesmann method. Also, rolling process has started from the cold working and finished to the hot working. This rolling process has more advantage that make reduction of process and cost than existing extrusion. This process includes various and complex process parameters. Each of the process parameters affects forming result. Therefore, all of the process parameters should be considered in copper tube rolling. Rolling process for copper tube was successfully simulated and it should be useful to determine optimal rolling condition.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.10 no.5
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• pp.96-103
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• 2001

The quality requirements for thickness accuracy in cold rolling continue to become more stringent, particularly in response to exacting design specification from automotive customers. One of the major impacts from the tighter tolerance level is more unusable product on the head end and tail end of tandem mill coils when the mill is in transition to or from steady state rolling condition. A strip thickness control system for a tandem cold steel rolling mills is composed with blocked non-interacting controller and controllers for strip thickness and tension control of each rolling stands. An intelligent mathematical model included an elastic deformation of strip has been developed and applied to the field in order to predict the rolling force. The simulated results showed that the effect of elastic recovery should be included the model, even if the effect of elastic compression was not important.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.10a
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• pp.481-482
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• 2009