• Design & Manufacturing
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• 제9권1호
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• pp.5-8
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• 2015

The company Daewoo Precision Industries imported fine blanking press of 40 tons from Switzerland with fine blanking tool in order to produce the fuse part of bomb in 1978 at first in Korea. About 1985 the first fine blanking tool for producing the door lock parts was manufactured in the company Gold Star (now LG). And then this technology was grown up with the growth of automobile industries in Korea. Now 31 companies are closely related to the fine blanking technology and there are total 146 fine blanking presses in Korea. The developments of fine blanking technology in industries have been oriented to the production of precise fine blanking parts, the reduction of die roll height on fine blanking parts, the production of complex fine blanking parts with progressive fine blanking tool including forming and forging technology, the production of high-strength steel fine blanking parts and so on. Some R&D activities in KITECH were introduced.

• 기술혁신학회지
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• 제8권1호
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• pp.209-219
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• 2005

o Korea consumed total 198.5 million TOE and the portion of crude oil n was 100.4 million TOE in 2002 which marked the 10th largest energy consuming country and ranks the $4^{th}$ crude oil consumer in the world. o Industries consumed 51.5% of the total energy and 93% of industrial energy was used at the manufacturing industries such as steel, textile, chemical, food and beverage, pulp and paper, and timber industries, which lead to energy intensive industries numbered 110,000. o Also Korea ranks the $10^{th}$ greenhouse gas emission countries of the world (134.9 million TC) which may cause Korean industries to suffer severely during the implementation of United Nations Framework Convention on Climate Change (UNFCCC). o Therefore, the target of the study is to develop a model for the analysis and design of industrial complex by integration of the energy usage and environmental problems. o The research work contents are as followings: -Analysis of Korea energy consumption -Concept of the integration of energy and environment problems - Basic concept of industrial complex planning - Case study (1) - Recommendation and conclusion

• 한국농공학회논문집
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• 제56권3호
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• pp.11-17
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• 2014

We investigated the applicability of steel slag as a capping material in order to minimize phosphorus(P) release into seawater. Steel slag is a byproduct from the iron and steel industries and the use of steel slag has some advantages in respect of both cost and environmental concern. P removal by steel slag were studied in a batch system with respect to changes in contact time and initial concentration. Kinetic adsorption data were described well by pseudo 2nd order model, indicating rate limiting step for P adsorption to steel slag is chemical sorption. Equilibrium adsorption data fitted well to Langmuir isotherm model which describes for single layer adsorption. The maximum P adsorption capacity of steel slag was 7.134 mg-P/L. Increasing the depth of steel slag produced a positive effect on interruption of P release. More than 3 cm of steel slag was effective for blocking P release and 5 cm of steel slag was recommended as the depth for capping of P contaminated marine sediments. Increasing P concentration and flow rate had a negative effect on P removal ratio. It was concluded that the steel slag has a potential capping material for blocking P release from marine sediments.

• Steel and Composite Structures
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• 제10권6호
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• pp.475-487
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• 2010

Most of steel structures in various industries are subjected to corrosion due to environmental exposure. Corrosion damage is a serious problem for these structures which may reduce their carrying capacity. These aging structures require maintenance and in many cases, replacement. The goal of this research is to consider the effects of corrosion by developing a model that estimates corrosion loss as a function of exposure time. The model is formulated based on average measured thickness data collected from three severely corroded I-beams (nearly 30 years old). Since corrosion is a time-dependent parameter. Analyses were performed to calculate the lateral buckling capacity of steel beam in terms of exposure time. Minimum curves have been developed for assessment of the remaining lateral buckling capacity of ordinary I-beams based on the loss of thicknesses in terms of exposure time. These minimum curves can be used by practicing engineers for better estimates on the service life of corrosion damaged steel beams.

• Corrosion Science and Technology
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• 제18권6호
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• pp.258-266
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• 2019

The objective of this study was to evaluate corrosion resistance of additive manufactured 316L stainless steel and alloy 625 powders widely used in corrosion resistance alloys of marine industry in comparison with cast alloys. Directed Energy Deposition (DED) method was used in this work for sample production. DED parameter adjustment was also studied for optimum manufacturing and for minimizing the influence of defects on corrosion property. Additive manufactured alloys showed lower corrosion resistance in seawater compared to cast alloys. The reason for the degradation of anti-corrosion property was speculated to be due to loss of microstructural integrity intrinsic to the additive manufacturing process. Application of heat treatment with various conditions after DED was attempted. The effect of heat treatments was analyzed with a microstructure study. It was found that 316L and alloy 625 produced by the DED process could recover their expected corrosion resistance when heat treated at 1200 ℃.

• Journal of Welding and Joining
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• 제28권2호
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• pp.79-83
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• 2010

In this study, newly developed welding consumables for EGW were welded in EH 36 TM steel plates and their welded joints were evaluated in point of mechanical properties and microstructures compared with imported consumables. Newly developed welding consumables were evaluated as good arc stability and slag fluidity, substantially the same with imported products. The tensile strength of all welded joints were sufficient to meet the requirements specified in a ship’s classification(490~640MPa) and all areas of fracture were heat affected zone(HAZ). Charpy absorbed energy values of all EG welded metals were sufficient to meet the requirements of classification(min. 34J) and those of newly developed wires were evaluated to be better than those of imported wires. As a result observing microstructures of single and tandem EG welded metals through optical and scanning electron microscope (OM&SEM), no grain boundary ferrite(PF(G)) were created in a prior austenite grain boundary and a volume fraction of a fine acicular ferrite were observed very high.

• Journal of Welding and Joining
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• 제25권4호
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• pp.58-64
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• 2007

Recently, the electro-magnetic induction process has been utilizing to substitute the flame heating process in shipyard. However, few studies have been performed to exactly analyze the deformation mechanism of the heating process with mathematical model. This is mainly due to the difficulty of modeling the inductor travelling on plate during the process. In this study, heat flux distribution of the process is firstly numerically analysed with the assumption that the process has a quasi-stationary state and also with the consideration that the heat source itself highly depends on the temperature of base plate. With the heat flux, the thermal and deformation analyses are then performed with a commercial program for 34 combinations of heating parameters. The deformations obtained and heating parameters are synthesized with a statistical method to produce simplified formulas, which easily give the relation between the heating parameters and deformations. The formulas are well compared with results of experiment.

• Corrosion Science and Technology
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• 제3권2호
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• pp.59-66
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• 2004

In construction of new ships and large steel bridges in Korea, pre-construction primers (PCP), also known as shop primer, are routinely used and retained as an integral part of the protective coating system. Retention of PCP's can significantly reduce building schedule and cost. Retaining PCP through the so-called "sweep blasting" procedure eliminates or minimizes the necessity of a second blast operation, thus shortening overall schedule as well as reducing labor cost and hazardous waste disposal cost. This study evaluates the feasibility of retaining PCP as the part of primer for high performance protective coating systems applied to ships' hull, bottom and ballast tanks. Upon proving that the retention of the PCP is a viable option, the process of coating application can he improved significantly in terms of cost and working schedule of new ships and large steel bridges. Results indicate that use of the PCP via sweeping blasting in conjunction with standard high performance protective coating systems does not degrade the overall performance of the coating systems. At the same time, it is also highly recommended that the secondary surface preparation should consist of grit blasting of weld burnt and other damaged areas to SSPC SP-IO grade (Sa 2.5 Gr.), Near White Blast Cleaning with proper application and attention to detail.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2002년도 Proceedings of the International Welding/Joining Conference-Korea
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• pp.561-569
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• 2002

Laser has been called a "Quantum Machine" because of its mechanism of generation since the development on July 7,1960.by T.H.Maiman. We can now use this machine as a tool for manufacturing in industries. At present, 45kW CO2 laser, 10kW Nd:YAG laser, 6kW LD pumped YAG laser and 4kW direct diode laser facilities are available for welding a heavy steel plate of 40mm in thickness and for cutting metals at high speed of 140m/min. Laser Materials Processing is no longer a scientific curiosity but a modern tool in industries. Lasers in manufacturing sector are currently used in welding, cutting, drilling, cladding, marking, cleaning, micro-machining and forming. Recently, high power laser diode, 10kW LD pumped YAG laser, 700W fiber laser and excimer laser have been developed in the industrialized countries. As a result of large numbers of research and developments, the modem laser materials processing has been realized and used in all kinds of industries now. In the present paper, metallurgical studies on laser materials processing such as porosity formation, hot cracking and the joint performances of steels and aluminum alloys and dissimilar joint are discussed after the introduction of laser facilities and laser applications in industries such as automotive industry, electronics industry, and steel making industry. The wave towards the use of laser materials processing and its penetration into many industries has started in many countries now. Especially, development of high power/quality diode laser will be accelerate the introduction of this magnificent tool, because of the high efficiency of about 50%, long life time and compact.

• 대한산업공학회지
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• 제3권2호
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• pp.29-40
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• 1977

Some of the steel works and machine tool manufacturers representing the whole spectrum of these industries in Korea are surveyed with a viewpoint from total quality control. The operation of quality control system in these fields has been found to be unsatisfactory partly because these industries are relatively young compared with those in advanced foreign countries, and partly because there have been insufficient financial and top management support. Some suggestions are made for the improvement of steel and machine tools quality. One of them is introducing the industrial engineering techniques, with additional quality control costs and full management support, into the company-wide quality control system.