• Journal of the Korean Society of Systems Engineering
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• v.10 no.2
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• pp.21-31
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• 2014

Recently, global market competition of iron and steel products is ever increasing due to over-supply from increased number of industries in rapidly growing countries, such as China, Brazil, and Indonesia. To occupy the big market, major industries are trying to develop high quality, high performance steel products via developing a new iron and steel making process. In other words, development of a new and innovative steel plant is a key to cope with the tough situation. Design and development for the life cycle of iron and steel making plant is very much complex and multi-disciplinary. In this paper, Plant Systems Engineering (PSE), a tailored SE process for industrial plant based on ISO/IEC 15288 is used for the design of Continuous Casting Process (CCP) Plant system. The CCP is a crucial process in steel making plant, whose design technology is occupied by the advanced foreign companies. For the sake of increasing engineering capability for the design of CCP, we applied PSE Process for the renovation of the existing CCP Process. Through the study, we were convinced that the applied method can be used for other plant systems, and SE is really the way of thinking, design, and development of modern complex and multi-disciplinary systems where high risk factors are present throughout the whole life cycle.

• Journal of Korea Foundry Society
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• v.8 no.4
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• pp.429-436
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• 1988

The influences of some casting conditions on bonding ratio and state at bonding zone of stainless steel-cast iron dual tube produced by centrifugal casting process were investigated to estimate fabrication technics. 1) Bonding ratio is increasing such as increasing of inner surface temperature of outer metal(stainless steel STS 304), if pouring temperature of inner metal (cast iron) is constant. 2) The more pouring temperature of inner metal (cast iron) increase, the more bonding ratio increase when inner surface temperature of outer metal (cast iron) is constant. 3) As the mold rotary speed is increase, the hatching area of bonding map (perfect bonding area) goes down to the low pouring temperature of inner metal. 4) In order to predict bonding state of two different metal, we are able to make and use the bonding map about casting conditions such as inner surface temperature of outer metal, pouring temperature of inner metal and mold rotary speed.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.55 no.12
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• pp.617-622
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• 2006

It is necessary to measure precisely the magnetic characteristics of electrical steel sheets under rotating magnetic fields, to obtain an accurate numerical performance analysis of electric machines made of electrical steel sheets. In this paper, the two dimensional magnetic characteristics of an electrical steel sheet are measured and explained under rotating magnetic fields using a two-axes-excitation type single sheet tester (SST). Through experiments, the magnetic properties, under rotating magnetic fields, of a non-oriented and grain oriented electrical steel sheet were measured respectively. In addition, the iron losses due to not only the alternating magnetic fields, but also rotating magnetic fields were measured. These experimentally measured results can evidently be applied to the analysis of iron losses in electrical machines.

• Journal of Korea Foundry Society
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• v.28 no.2
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• pp.52-56
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• 2008

• Journal of the Korean institute of surface engineering
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• v.31 no.2
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• pp.101-108
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• 1998

The effect of oxidation-reduction heating conditions on coating adherence of hot-dip galvanized steel containing silicon has beeninvestigated. The presence of a stbke sillicon oxide formed on the steel surface has been shown to be very detrimenal to proper wetting by liquid zinc. When the steel has more than the critical sillicon content neeled to from a stable external oxide, the use of oxidation-reduction method has been found successful in obtaining a good quality, coated product with excellence adhreence. This can be explained by the formation of an iron oxide. The iron oxrtion of the scale is reduced, leaving the stable oxides dispersed in a fresh metallic iron surface layer. This reduced iron surface is easily wetted by the liquid zinc and excellent adherence is obtained.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.625-626
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• 2008

The magnetic domain-refining techniques such as ball scratching, laser irradiation and plasma have been developed to reduce the domain wall spacing and thus iron losses in Fe-3%Si grain-oriented silicon steels. In view point of magnetic properties, it was supposed that the locally residual stresses change the magnetoelastic energy of the material and thus the spacing between $180^{\circ}$ domain walls decreases in order to reduce the magnetostatic energy. The effect of laser irradiation on iron loss and magnetostriction reduction for Fe-3%Si grain-oriented steel were investigated. Since the local tensile stresses were induced at the surface of Fe-3%Si steel by the laser irradiation, the minimum iron loss caused by reducing eddy current loss was obtained in spiete of the decrease of permeability by hindering eddy current loss was obtained in spite of the decrease of permeability by hindering the domain wall movement around the induced stress field. Furthermore, the laser treated 3%Si steel has lower magnetostriction as compared to non laser-treated steel and is less sensitive to applying pre-stresses due to the volume reduction of $90^{\circ}$ domain in materials.

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.398-403
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• 2001

There is a potential usability of electric arc furnace(EAF) dust produced during the iron manufacturing process as a recycled resource, because valuable materials such as Zn, Pb and Fe are contained in it. In this study, metallic Zn was recycled from the fine electric arc furnace dust by a solid state reduction method using carbon at relatively low temperature. It was possible to recover metallic zinc by using of high vapour pressure of zinc with this reduction method. The feasibility of recycled zinc for cold bonded pellet(CBP) was investigated. The main composition of EAF dust were franklinite(ZnFe$_2$O$_4$), magnetite(Fe$_3$O$_4$) and zincite(ZnO), and Pb and Cl were completely removed by a heat treatment in oxidation environment. The reduction ratio increased as the solid carbon content increased, and it increased with decreasing of dust particle size and increasing of compaction pressure due to a increase of contact area.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.3
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• pp.33-38
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• 2010

In this paper, the nature of iron loss in electrical steel during alternating field excitation is investigated more precisely. The exact definition of AC iron loss is cleared by accurately measuring the iron loss for conditions of both the sinusoidal magnetic field and sinusoidal magnetic flux density. The results of this approach to iron loss calculations in electrical steel are compared to experimentally-measured losses. In addition, an inverse hysteresis model considering eddy current loss was developed to analyze the iron loss when the input is the voltage source. With this model, the inrush current in the inductor or transformer as well as the iron loss can be calculated.

• Journal of Navigation and Port Research
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• v.44 no.2
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• pp.128-135
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• 2020

Long-term shipping contracts represent the cooperative and coexisting relationships between the shipping and steel industries. Yet, differences between the contract forms for iron ore and steel products have emerged. Specifically, the large proportion of consecutive voyage charters (CVC) is being applied in the iron ore trade, whereas the contract of affreightment (COA) is proportionally higher for shipping steel products. The literature review and in-depth interviews in this study identified through the research model, the characteristics of the shipping and market structure in both markets have significantly contributed to the preference of different long-term contracts. It has been determined that the mutual oligopoly market structure and the characteristics of shipping such as, the small number of suitable vessels in the market, the single fixed load/discharge ports, the long-distance voyages, and the potential risks for fatal accidents because of cargo liquefaction, for the iron ore trade, provide higher contribution to the preference of CVC contracts. In contrast, the consignor oligopoly market structure and the shipping characteristics, such as the greater number of suitable vessels available in the market, the variation in ports, the cargo quantity per shipment, the various load/discharge ports, and the need for experienced carriers for steel product loading in the steel product trade has shown higher preference on the COA contracts as the consignors with superiority over the shipowners, resulting in favorable contract types and conditions for the consignors.

• Proceedings of the Optical Society of Korea Conference
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• 2000.02a
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• pp.240-241
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• 2000

Sapphire fiber has been used to provide an optical path for the total radiation pyrometry. In measuring the temperature, we use the two-color detector, which consists of a high-performance Silicon detector mounted in a "sandwich" configuration over a Germanium detector. Sapphire fiber can withstand high temperature in the molten steel for two and a half hours. The maximum value of the error is the $\pm$2.5$^{\circ}C$ in the range of 152$0^{\circ}C$~1$600^{\circ}C$. This paper presents the simple scheme for measuring the molten steel temperature in the blast furnace of the iron ＆ steel making process.g process.