• 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.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.1480-1483
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• 1996

A set of approaches suggested to control the eccentricity is discussed in this paper. Among these, filter-integrator method is used to design the controller, which also includes the input signal synchronization, stabilizing filter and eccentricity source discrimination. Using the S/W that is coded for real time application of that controller, we simulated the operations of that one. The simulation results show the characteristics of eccentricity compensation and eccentricity discrimination. However, from these results, we can see that only proper stabilization strategy certificates the safe eccentricity control.

• 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.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2000.04a
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• pp.52-55
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• 2000

Investigated via a series of finite element process simulation is the effect of diverse process variables on some selected non-dimensional parameters characterizing the strip in hot strip rolling. Then on the basis of these parameters an on-line model is derived for the precise prediction of roll and roll power. The prediction accuracy of the proposed model is examined through comparison with predictions from a finite element process model.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2005.10a
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• pp.453-455
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• 2005

Ferritic STS 439 Steel sheet were deformed by hot rolling with and without lubricant. The effect of friction between roll and specimen on inhomogeneous texture was studied by means of EBSD, XRD texture analysis. The textures were compared with those of obtained by Taylor FEM simulation. High friction between roll and sheet gave rise to the formation of the inhomogeneous shear texture through thickness.

• Transactions of Materials Processing
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• v.6 no.2
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• pp.161-175
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• 1997

The effects of various process paramenters on the detailed aspects of the thermo-mechanical behavior of work roll and on the roll life are investigated via a series of process simulation, using a mathematical model presented previously. The process conditions are discussed that are favorable or optimal in terms of reducing roll wear in the front finishing stands.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2000.04a
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• pp.48-51
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• 2000

In plate mill studies on crop decrease of the top and bottom ends of hot rolled plate have been performed. The plane view shape for the thin plate after broadside rolling was controlled by roll gap difference with AGC in broadside rolling process. New models for thin slab after broadside rolling have been formulated based on the actual production rolling data to give optimal rolling condition A new plate rolling method called by dog bone rolling has been applied making it is possible to prevent non-uniform plastic deformation at top and bottom ends. By new rolling method crop losses of rolled plate have been improved by 10% on average with an effective fishtail crop shape.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2003.05a
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• pp.184-187
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• 2003

The simulation program is developed to get the target strip crown of high strength steel in the continuous hot strip rolling. The developed program consists of several sub-program, which contains work roll shifting pattern, roll wear profile, roll thermal expanded profile and strip profile. Also, the variation of strip profile is investigated according to roll deflection and flattening. The results are compared with the values observed from the actual hot rolling of high strength steel. And effect of bender force on the strip profile is studied. The strip crown is shown to decrease with increasing bender force.

• 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.

• Korean Journal of Materials Research
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• v.23 no.11
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• pp.607-612
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• 2013

A powder in sheath rolling method was applied to the fabrication of a carbon nano tube (CNT) reinforced aluminum composite. A 6061 aluminum alloy tube with outer diameter of 31 mm and wall thickness of 2 mm was used as a sheath material. A mixture of pure aluminum powder and CNTs with a volume content of 5% was filled in the tube by tap filling and then processed to an 85% reduction using multi-pass rolling after heating for 0.5 h at $400^{\circ}C$. The specimen was then further processed at $400^{\circ}C$ by multi-pass hot rolling. The specimen was then annealed for 1 h at various temperatures that ranged from 100 to $500^{\circ}C$. The relative density of the 5vol%CNT/Al composite fabricated using powder in sheath rolling increased with increasing of the rolling reduction, becoming about 97% after hot rolling under 96 % total reduction. The relative density of the composite hardly changed regardless of the increasing of the annealing temperature. The average hardness also had only slight dependence on the annealing temperature. However, the tensile strength of the composite containing the 6061 aluminum sheath decreased and the fracture elongation increased with increasing of the annealing temperature. It is concluded that the powder in sheath rolling method is an effective process for fabrication of CNT reinforced Al matrix composites.