• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.132-132
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• 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.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.10a
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• pp.41-46
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• 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.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2009.04a
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• pp.73-76
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• 2009

Increase in tensile strength of steel is important for fuel efficiency and $CO_2$ reduction. But the higher the strip strength, the more defect could be generated in hot strip mill. This study focuses on line-type edge scab. One of the causes for the defect is initial edge cracks commonly observed on a slab but their correlation has not been verified yet. Thus, the objective of this report is to verify if the edge crack is exactly the seed for edge scab. For this, we conducted pilot hot rolling test with cracked slab and compared the development of cracks and edge scabs on hot-rolled strip.

• 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.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.175.1-175
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• 2001

This paper handles main automation facilities and important control issues for hot rolling mill processes. Starting from the general procedures of production cycle, detailed tension control applications are handled based on field experiences and published research papers. Nowadays, quality control and delivery time control for products is becoming more and more important as the client demand is tighter than any other period. In this respect, control technology in steel making process takes very important position. Therefore, the objective of this paper is to share control problems with the people in academic field and by doing so, to get new and striking solution for the problems.

• Transactions of Materials Processing
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• v.8 no.1
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• pp.78-91
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• 1999

The endless hot rolling has been focused as an innovative process technology for increasing the productivity drastically and reducing the imperfection of quality in hot rolled steel strip. To realize it in actual mill, a lots of new facilities such as bar coiler, movable LASER welder and high speed strip shear should be equipped. And also it is necessary to develop the control technique for changing the roll gap and rolling speed during rolling, which is named as Flying Gap and Speed Change control technology. To prevent a strip rupture caused by excessive tension, it is very important to minimize fluctuations in strip thickness and intension during FGSC control. In this paper, the mathematical model for FGSC control algorithm was suggested and dynamic simulation is performed to accertain the effect of suggested control method on fluctuations in strip thickness and tension. For endless hot rolling simulation, a lots of FGSC control situations, for instance - strip thickness change from strip to strip - strip width change from strip to strip - carbon content change from strip to strip are considered.

• The Journal of the Korea institute of electronic communication sciences
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• v.11 no.4
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• pp.387-394
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• 2016

Today, hot rolled mill plant are currently operating 24 hours a day. The main processes of hot-rolled steel mill are Reheating Furnace, Roughing Mill, Fishing Mill and the Down Coiler. In the process checking over the thickness and width of rolled material, temperature control is an important factor. It is quite often the cause of the work breakdown and find a bad elements for product. After the shipping out the product, when a claim occurs requires an investigation. In each process of the conventional thickness gauge, width, and thermometer. Operation by an independent data acquisition and this monitoring is problematic and straining of the operator. The monitoring process the data of each function and incorporate monitoring results can also check future work. The installation of this system will improve our efficiency and productivity. In the rolling process by developing more efficient operating quality monitoring system, this will be made possible.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.1469-1472
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• 1996

Hydraulic Hot Strip Mill (HHSM) rolls materials whose size and stiffness are various. So a roll gap controller for HHSM was designed using TDC(Time Delay Control) method. The performance of the roll gap control was evaluated through computer simulations. The simulation results indicate that TDC method show excellent robustness and tracking properties against PID control method in various rolling conditions.

• Korean Journal of Metals and Materials
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• v.46 no.4
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• pp.257-266
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• 2008

AHydrogen induced cracking (HIC) was phenomenologically studied in terms of the effect of nonmetallic inclusions and hot rolling process parameters. By comparing the level of non-metallic inclusions in two different kinds of commercial grade steels having different HIC resistance, the role of non-metallic inclusions in HIC occurrence was investigated. Change in inclusion morphology and distribution during hot rolling was also studied throughout slab, rolling at austenite recrystallization region (roughing mill; RM) and rolling at austenite non-recrystallization region (finish mill; FM). In addition, the contribution of RM and FM parameters to HIC was investigated from the standpoint of change in inclusion morphology during hot rolling processes. As a result, HIC was closely related to the separation of large complex inclusion during hot rolling process. Large complex inclusions originated from the improper Ca treatment, after which equilibrium composition of slag should have resulted in eutectoid composition. By controlling the equilibrium slag composition equivalent to eutectoid one, HIC resistance could be improved due to the reduced size of inclusions. In addition, change in reduction/pass in RM had an effect on HIC resistance of steels while that in FM did not. Increase in the reduction/pass in the latter stage of RM improved HIC resistance of steels by enhancing the void enclosure around inclusions.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1999.08a
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• pp.438-446
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• 1999

Crop minimization of the top and bottom ends of hot rolled plate, in a plate, in a plate mill, has been investigated. The existing model to determine the edging pattern at the finishing rolling pass was not reasonable to get high width accuracy and rolling yields. New models including width prediction have been formulated by using neural network model of back propagation learning algorithm and statistical analysis based on the actual production rolling data to give the optimal pattern for minimizing trimming loss. Using these models, at a given rolling condition of broadside pass and finishing pass and the permissible condition of width variation, it was possible to minimize crip at the top and bottom ends according to optimum procedure in plate mill. An application to improve the plan view pattern reduced width variation by 23% and crop length by 30% on average with an effective fishtail crop shape.