• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2003년도 추계학술대회논문집
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• pp.140-143
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• 2003

The drawbead is an important part in sheet metal forming for automotive part and its effect is affected by various process parameters. Therefore in this study, drawbead friction test was performed at various process parameters - panels (cold rolled and galvanized sheet steel), lubricants (having three different viscosities), bead materials(steel, iron) and surface treatment of bead (Cr plating). Circular shape bead has been used for the test. The results show that friction and drawing characteristics were mainly influenced by the nature of zinc coating, viscosity of lubricants, surface treatment of a bead and hardness of coated layer.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1994년도 춘계학술대회 논문집
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• pp.92-100
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• 1994

Forming limit diagrams for three different galvanized deep drawing quality steel sheets have been measured by hemispherical punch stretching. The experimental forming limit diagrams have been compared with results calculated using the shear instability criterion and the M-K model which takes into account a strain gradient effect resulting from bending (curvature) of a flat sheet by punch stretching. The measured data were in good agreement with the results calculated using exponent M value of 8 in Hosford's yield criterion for the M-K model and M= 6 for the shear instability model.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 1999년도 춘계학술발표회 초록집
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• pp.94-94
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• 1999

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2000년도 추계학술발표회 초록집
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• pp.47-47
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• 2000

• Corrosion Science and Technology
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• 제22권2호
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• pp.123-130
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• 2023

This study aimed to evaluate corrosion resistance of steel coated with GI and Zn-Al-Mg alloy using cyclic corrosion test (CCT) with electrochemical polarization and impedance measurements. Results showed that the Zn-Al-Mg alloy coated steel had a much higher corrosion rate than GI coated steel in early stages of corrosion. With prolonged immersion, however, the corrosion rate of the Zn-Al-Mg alloy coated steel greatly decreased, mainly owing to a significant decrease in the cathodic reduction reaction and an increase in polarization resistance at the surface. This was closely associated with the formation of protective corrosion products including Zn₅(OH)₈Cl₂·H₂O and Zn₆Al₂(OH)₁₆CO₃. Moreover, when the steel substrate was locally exposed due to mechanical damage, the kinetics of anodic dissolution from the coating layer and the formation of protective corrosion products on the surface of the Zn-Al-Mg alloy coated steel became much faster compared to the case of GI coated steel. This could provide a longer-lasting corrosion inhibition function for Zn-Al-Mg alloy coated steel used in plant farms.

• Corrosion Science and Technology
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• 제12권1호
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• pp.1-6
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• 2013

Recently Digital TV industry has drastically been moving the illuminating system, which causes an obvious product change from PDP and LCD to LED model to provide high-definition image. Due to strong competition in the digital industry, TV manufacturers make a great efforts to reduce production cost by using low-priced materials such as steels instead of aluminum and plastic etc. In this paper we have developed a new low-priced electrogalvanized steel sheet, which has a black resin composite layer, to substitute conventional high-priced PCM steel and plastic mold for rear cover panel in the digital TV. The black resin composite was prepared by mechanical dispersion of the mixture solution that consists of high solid polyester resin, melamine hardener, black pigment, micronized silica paste, polyacrylate texturing particle and miscellaneous additives. The composite solution was coated on the steel sheet using roll coater followed by induction furnace curing and cooling. Although the coated layer has a half thickness compared to the conventional PCM steels having $23{\mu}m$ thickness, it exhibits excellent quality for the usage of rear cover panel. The new steel sheet was applied to test products to get quality certification from worldwide electronic appliance customers. Detailed discussion provides in this paper including preparation of composite solution, roll coating technology, induction curing technology and quality evaluation from customers.

• 대한기계학회논문집
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• 제14권6호
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• pp.1474-1486
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• 1990

본 연구에서는 자동차용 표면처리 강판의 스탬핑 성형에 있어서 도금 종류별 도금층의 표면특성과 마찰, 윤활특성의 상관관계를 규명하고, 스탬핑 성형특성을 파악 하여 도금 종류별 최적 성형조건을 도출하고자 한다.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 1998년도 특별강연 및 추계학술발표 개요집
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• pp.303-304
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• 1998

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2001년도 춘계학술발표회 초록집
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• pp.25-26
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• 2001

• 한국표면공학회지
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• 제24권1호
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• pp.40-40
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• 1991

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