• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2003.05a
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• pp.225-229
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• 2003

When hot strip is trimmed in the side trimming process at the entry side of tandem cold rolling mill, due to bad quality of trimming face and burr, product quality(saw ear)becomes so bad that it causes drop of yield and claim from customers. Therefore, it was examined that applying ultrasonic vibration is an effective method to improve quality of strip trimming face and decrease burr magnitude by decreasing shear force acting between strip trimming face and knife in side trimming process of cold rolling.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.22 no.4
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• pp.723-730
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• 1998

With the introduction of edge drop control system in Tandem Cold Rolling Mill, it is necessary to develop te numerical expression for the set-up and edge drop automatic control of cold rolled sheet. As a first step we developed a simulation program which predicts profile and the amounts of edge drop at the delivery side of each stand by using roll deformation anlysis with the slit roll model. And by using the program the effect of various rolling conditions on edge drop was investigated. As a result the relations were obtained between the amounts of edge drop and rolling conditions. Based on above relations, the numerical expression was developed for the set-up and automatic control of edge drop by multi-regression of simulation results for the variation of edge drop amount with each rolling condition.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1993.10a
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• pp.512-517
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• 1993

The cold rolled strip meets continuously rising demands on the less deviation of thickness at the width direction of their rolled products. Especially, the special interest has been to find the methods to reduce the edge drop which influences seriously on the yield losses and the quality of the rolled products. In this study, the influence of hot coils on the thickness profile of cold rolled strip was analyzed. For obtainint the tapered work roll shig\ft conditions, the thermal crown and the flattening between the work roll and the strip were calculated, and the main parameters which have mostly effects on the edge drop were simulated. Also the obtained conditions from the simulation were applied to Tandem Cold Rolling Mill to investigate the change of the edge drop and the crown ratio depending on the amount of work roll taper and the length of contact of taper. The results of the application led to better thickness profile than conventional one.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2009.04a
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• pp.117-120
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• 2009

The rolling of flat slabs or sheet metal is probably the most advanced technique of metalworking technology. In spite of this very intensive activity, the problem if edge cracking has not been resolved. Although edge cracking is a major industrial problem, relatively little well-documented experimental work has been published on subject. Despite the paucity of exact experiments, it is reasonably certain from published data that three causes contribute to its occurrence; (1) limited ductility of the rolled material (2) uneven deformation at the edges and (3) variations in stresses along the width of the rolled material, particular near the edge. The present study was carried out to show the generation of edge cracking using ductile fracture criteria and FE-simulation. The validity of simulated results was verified by rolling experiments of steel strip.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.19 no.12
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• pp.1252-1259
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• 2009

Due to the international competition and global pressure, the roll speed is increased. However, higher speeds increase the power density in the process as well as the plant's potential to react with vibrations. Under certain operating conditions, vibrations may occur, which again cause chattermarks, strip rupture or coil break fault. The appropriate condition monitoring is needed to improve product quality and availability. The aim of condition monitoring is to reduce maintenance costs, increase productivity and improve product quality. This paper proposes a condition monitoring tool designed for the classification of coil break fault. This method is used to cold rolling mill for faults monitoring based on vibration and motor current signals. The results show that the performance of classification has high accuracy based on experimental work.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.684-687
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• 1997

In order to access to the Business Computer (B/C), the Process Computer(P/C), and the Database Server in one terminal, the Open Man Machine Interface (MMI) System has been developed. The testbed to develop the interface functions for B/C, P/C, DB server, and CCD camera were constructed, which consisted of Workstations and Personal Computers (PC). Graphic display programs Monitoring the process states of Tandem Cold Mill plant were developed using four Graphic User Interface tools: InTouch, FIX32, Open Interface Environment, and ILOG Views. With regard to the CPU utilization and response delay required to open new display, the performance tests have been carried out on each MMI platform.