• Journal of the Korean Society for Heat Treatment
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• v.11 no.1
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• pp.62-72
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• 1998

High carbon steel is used for rails due to the excellent wear resistance, however the welding of high carbon steel is more difficult than that of mild steel owing to the high hardenability and sensitivity to cracking at the weldment. In this study, the impact toughness and cracking behavior of a rail weldment were evaluated as function of preheating temperatures. Impact toughness were more excellent in the specimen welded with preheating temperature above $250^{\circ}C$ than that below $100^{\circ}C$, and cracks were not detected in the specimen welded with preheating temperature above $250^{\circ}C$.

• Journal of the Korean Ceramic Society
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• v.40 no.12
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• pp.1141-1149
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• 2003

Refractory industry in technologically advanced countries has long been on gradual decline due to leveled-off steel production and decreasing unit consumption of refractories for steel. Notable technological achievements by refractory industry that contributed significantly to steel production are briefly reviewed covering from blast furnace, basic oxygen furnace to continuous casting. Future possibility to revitalize the refractory industry is discussed on the basis of the review, taking into account opportunities available in environment and energy related sector of industries.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.3
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• pp.497-504
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• 2002

The purpose of this study is to analyze thermal cycles and to investigate microstructures of heat affected zones for a low alloy carbon steel pipe under a multipass weld. The commercial finite element code SYSWELD is used to compute thermal cycles during multipass weld. The numerical results such as thermal cycles and size of heat affected zone are compared with those of the experiment and the two results show a good agreement. In addition, the microstructure and hardness are investigated from the weldment in detail. The weakest location is founded at intercritical region near the base metal.

• Special Issue of the Society of Naval Architects of Korea
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• 2017.10a
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• pp.105-108
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• 2017

Condensation is one of the common issues which we can easily see in everyday life. For example, the surface of glasses with cold water is easily moisturized. This wet surface gives us uncomfortable feeling and is sometimes dangerous because it is slippery. As the safety on working space is one of the most important issue on offshore project, condensation is also important matter to take care of with precaution. Since the bottom of vessel or offshore facility is submersed in the water, the risk of having condensate on the steel surface is getting higher because sea water temperature is normally lower than ambient temperature. And if there is any electric equipment or person working in that space, condensation is normally not allowed. The pontoon of semi-submersible drilling rig is such a space which is submersed, with electric and mechanical equipments and person working periodically. To prevent condensation in pontoon, study was conducted by checking several cases.

• Corrosion Science and Technology
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• v.5 no.1
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• pp.27-32
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• 2006

One of the critical issues in the coating specification is the allowable limit of surface contaminant(s) - such as soluble salt(s), grit dust, and rust - after grit blasting. Yet, there is no universally accepted data supporting the relationship between the long-term coating performance and the amount of various surface contaminants allowed after grit blasting. In this study, it was attempted to prepare epoxy coatings applied on grit-blasted steel substrate dosed with controlled amount of surface contaminants - such as soluble salt(s), grit dust, and rust. Then, coating samples were subjected to 4,200 hours of cyclic test(NORSOK M-501), which were then evaluated in terms of resistance to rust creepage, blistering, chalking, rusting, cracking and adhesion strength. Additional investigations on the possible damage at the paint/steel interface were carried out using an Electrochemical Impedance Spectroscopy(EIS) and observations of under-film-corrosion. Test results suggested that the current industrial specifications were well matched with the allowable degree of rust, whereas the allowable amount of soluble salt and grit dust after grit blasting showed a certain deviation from the specifications currently employed for fabrication of marine vessels and offshore facilities.

• Environmental and Resource Economics Review
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• v.10 no.2
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• pp.135-159
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• 2001

This study analyses the energy consumption increase by using a physical production index (PPI) based decomposition method. The energy efficiency of the Korean industry deteriorated to a large extent in the 1992 to 1997 period. This outcome, however, does not contradict the result of a previous study that the physical energy intensities (measured by energy use per production unit) decreased in four Korean energy intensive industries such as steel, cement, petrochemical and pulp and paper in the same period. Although the physical energy intensities in four industries considered decreased significantly, the energy efficiency of the Korean industry deteriorated because the increase in the value-added production was smaller than that in the physical production except for the steel industry. This outcome suggests that the reduction in the physical energy intensity alone will not result in reducing the economic energy intensity, thereby reducing the increase in the energy consumption of the Korean industry. Therefore, it necessitates to restructure the Korean industry towards a higher value-added production and to strengthen energy efficiency improvement efforts in the Korean industry. As the overinvestment in the energy intensive industries caused a deep price fall of Korean products and a reduction of the value added of the Korean industry and with it an increase in the economic energy intensity, a decrease in this intensity will highly depend on reducing the overcapacity in the energy intensive industries which was partly responsible for the currency and economic crisis of 1997.

• Proceedings of the Korean Nuclear Society Conference
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• 2005.05a
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• pp.1082-1083
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• 2005

• 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.

• Proceedings of the KIEE Conference
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• 1999.11b
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• pp.40-42
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• 1999

In this paper, light-weight system of linear induction motor(LIM) for light railway train is presented, and is compared with former type of LIM. For the light-weight system without modification of motor size the material of primary core(silicon steel) is changed with iron-cobalt alloy and the material of primary winding(copper) is changed with aluminium. The characteristics of LIM are analyzed. Specially, the air gap magnetic flux density distribution due to end effect is showed with motor velocity, we will present papers continuously through designing and testing a trial product.

• Journal of Power System Engineering
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• v.7 no.2
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• pp.66-72
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• 2003

Recently, the steel parts used at the aerospace and automobile industries are required to be used light weight parts. Therefore, used material, steel have to be a high stress, which is an indispensable condition in this field. At the consideration of parts design, high hardness of the lightweight parts have an benefit of saving fuel and material. A high stress of metal has a point of difference according to the shape of design, external cyclic load and condition of vibration. A crack generates on the surface of metal or under yield stress by defect of inner metal defect or surface defect and slowly, this crack grow stable growth. Finally, rapidity failure phenomena is happen. Fatigue failure_phenomena, which happen in metal, bring on danger in human life and property therefor, anti-fatigue failure technology take an important part of current industries Currently, the shot peening is used for removing the defect from the surface of steel and improving the fatigue strength on surface. Therefore, this paper investigated the effect on frcature toughness using shot peening which is improve the resistance of crack growth and crack expansion rate by fatigue that make a compressive residual stress on surface.