• Proceedings of the KSME Conference
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• 2007.05b
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• pp.2654-2659
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• 2007

Fluid flow and temperature distribution inside a molten zinc bath were investigated by computational fluid dynamics method. Modeling the channel inductor where alternating current of 60Hz was applied, Lorentz force and generated heat were obtained and later supplemented as source terms to momentum and heat equations. The present work validates CFD technique is effectively adopted when the inductor hardware modification or its configuration is considered for the optimum flows.

• Journal of the Korean institute of surface engineering
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• v.31 no.6
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• pp.379-388
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• 1998

The iron-zinc interfacial reaction and corrosin properties in galvanizing bath containning Ni have been intestigated. The substrate steel plates were galvanized in Zn or Zn-0.018Al baths with various Ni contents. The corrosion resistance of galvanized specimens was also evaluated by $60^{\circ}$bending test for galvannealing speaaimens. The corrosion resistance was improved with Ni addition in pure Zn bath, while deteriorated with Ni addition in Zn-0.18Al bath. The anti-powdering property, on thhe otherhand, was improved with Ni addition in Zn-0.18Al bath, while deteriorated with Ni addition in pure Zn. It was found that the anti-powdering property was improved with increasing $\xi$ phase ratio in reaction layer.

• Journal of Welding and Joining
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• v.19 no.5
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• pp.512-519
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• 2001

Sink roll has been used in molten Zn-0.2%Al alloy bath of continuous galvanizing line in sinking and stabilizing process of the steel strip in molten metal bath. In this process, although the scraper scraps off the sink roll surface, the dross compounds is builded up on the sink roll surface and the life time of the sink roll is shorten by the dross compounds. The present study was investigated the application of the spray coating layer on sink roll body for improving durability In molten Zn-0.2%Al alloy. Through the durability tests in molten Zn-0.2%Al alloy with various ceramic and cermet coating layer, the optimum bond and top coating material was obtained. As the results, the system of STS430F base metal, WC-l7Co bond and $ZrO_2-SiO_2$ top coating was clarified to be the best quality of durability in molten Zn-0.2%Al alloy.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.1488-1491
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• 1996

Throughout CGL(Continuous Galvanizing Line) in steel works, zinc-coated steel sheets are produced which are used where long-running corrosion resistivity is required. During the galvanizing process, top dross is created and floated on the zinc pot. Because the dross leaves ill patterns on the coated sheets, it is removed manually with shovel-like tools in about twenty minutes. Because, however, the working environment is very noisy, hot and harmful to human workers, a robot system is developed and implemented on a real plant to automatically remove the top dross. It consists of a robot and its carriage system, a pot level sensor, a system controller, and special tools to collect, pick up, and put the top dross into a dross waste basket. A system software is developed to monitor the system status. A series of tests were performed to verify the robot motion and adaptation to working conditions, and proved successful work.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.836-839
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• 1996

Throughout CGL (Continuous Galvanizing Line) in steel works, zinc-coated steel sheets are produced which are used where long-running corrosion resistivity is required. During the galvanizing process, top dross is created and floated on the zinc pot. Because the dross leaves ill patterns on the coated sheets, a robot system is developed to automatically collect and remove the top dross. It consists of a robot and its carriage system, a pot level sensor, a system controller, and special robot tools. For the first time the level of zinc pot must be measured and fed back to the robot controller to avoid submersion of the robot hand into the hot zinc pot. In this paper, acoustic distance sensor is tested as a candidate for the pot level sensor in the view point of hot environment. Some considerations on the use of the acoustic distance sensor will be denoted.

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.281-285
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• 2001

This technology Provides an economical Production of high value added goods applicable to electro chemicals by recycling of waste products in EGL(Electro Galvanizing Line). The waste products produced in EGL contain potassium chloride (KCI), nickel and zinc. Highly pure KCI and Zinc Chloride which are raw material of electro plating, can be produced by the development of the recycling process. The scope of this study ranges from laboratory experiments to pilot test in plant. We have developed the whole process of recycling technology such as purification method of waste products, fabrication methods of electro chemicals, basic design of plant, pilot scale production and evaluation of pilot goods, Developed electro chemicals were pure enough to satisfy the specification of steel company.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1999.08a
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• pp.111-118
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• 1999

This article describes the basic engineering concepts to be considered in the application of an induction heating furnace in the hot-dip galvanizing line. Experience in the Dongkuk project in Pohang, has shown that this arrangement has many advantages over the conventional method of using a combustion-gas heated furnace. Investment and operating costs are lower, the line length is much shorter, line operation is more convenient, air pollution is reduced, and the coated strip at of top-quality. As these benefits become well known, it is anticipated that the concept of induction heating will be more widely used in both new and revamped process lines. Induction heating is suitable for the production of Commercial Quality hot galvanized coils. More research is required to extend the present concept to the production of higher forming grades such as Drawing, Deep Drawing and Extra Deep Drawing Quality steels. A combination of induction heating and combustion-gas heating may lead to the way to the processing of these qualities of strip.

• Journal of the Korean institute of surface engineering
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• v.36 no.5
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• pp.364-372
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• 2003

In continuous galvanizing process, dissolution of iron into molten zinc results in a fairly great amount of dross. In order to decrease dross, the amount of dissolved iron of strip in molten zinc was investigated in the range of 0∼0.22%Al content, 440∼$470^{\circ}C$ strip temperature and 3∼60 sec dipping time. Uniform Fe-Al-Zn inhibition layer was formed in the coating layer/strip interface not only in the grain boundary but also in the grain of substrate with the increase of Al content in the zinc pot, while the amount of iron dissolution was decreased. Inhibition layer was unstable as the dipping time and strip temperature increased and the amount of iron dissolution increased.

• Journal of ILASS-Korea
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• v.5 no.3
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• pp.45-54
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• 2000

A novel electrostatic splaying method for solidifying a galvanized coating layer was studied. Our experimental results and computer simulations showed that electric field could assist the fine droplets to attach on the steel surface and change the sprayed droplets trajectory especially in the space near the steel surface. It was necessary to apply the electric voltage higher than - 20 kV to obtain the enough electrostatic attraction force between droplets and the steel sheet.

• Corrosion Science and Technology
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• v.9 no.2
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• pp.67-73
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• 2010

Niobium microalloying is effective in hot-rolled and cold-rolled steels by providing a fine-grained microstructure resulting in increased strength. To optimize the strengthening effect, alloy design and hot-rolling conditions have to be adapted. As a key issue the dissolution and precipitation characteristics of Nb are discussed in particular with regard to the run-out table conditions. It is then considered how the hot-rolled microstructure and the solute state of Nb interact with the hot-dip galvanizing cycle. The adjusted conditions allow controlling the morphology and distribution of phases in the cold-rolled annealed material. Additional precipitation hardening can be achieved as well. The derived options can be readily applied to produce conventional HSLA and IF high strength steels as well as to modern multiphase steels. It will be explained how important application properties such as strength, elongation, bendability, weldability and delayed cracking resistance can be influenced in a controlled and favorable way. Examples of practical relevance and experience are given.