• 콘크리트학회지
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• 제8권4호
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• pp.15-24
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• 1996

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 1994년도 특별강연 및 추계학술발표 개요집
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• pp.45-47
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• 1994

• 접착 및 계면
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• 제15권3호
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• pp.116-122
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• 2014

자외선 경화법을 이용한 강판의 표면 코팅 시 사용되는 올리고머, 단량체, 광개시제 및 강판의 특성 등 주요 인자가 코팅 표면의 $20^{\circ}$ 및 $60^{\circ}$ 광택도(ASTM D523)에 미치는 영향에 대해서 연구하였다. 공정 변수에 대한 광택도의 변화는 $60^{\circ}$ 광택도에 비해 $20^{\circ}$ 광택도가 민감하게 변화하였다. 단독으로 올리고머를 사용할 경우의 경우, 광택도의 변화는 거의 없었으나, 올리고머의 혼합 비율이, 단량체의 종류와 혼합 비율, 올리고머와 단량체의 혼합 비율, 개시제의 종류와 함량 비, 강판의 종류는 광택도에 큰 영향을 주었다. 올리고머 혼합의 경우 폴리우레탄 아크릴레이트(UA)와 에폭시 아크릴레이트(EA)의 혼합 비율이 70 : 30, 단량체의 경우 트리메틸올프로판트리아크릴레이트(TMPTA)와 테트라히드로퍼퍼릴아크릴레이트(THFA)가 5 : 5의 비율로 혼합된 경우가, 혼합 올리고머(UA : EA = 70 : 30)의 함량이 90 wt%인 경우 최대의 광택도를 나타내었다. 광개시제 중 액체 타입인 Darocur MBF가 고체 타입인 Irgacure 184에 비해 우수한 광택도를 나타내었으며, 최소 투입량인 1 wt%의 농도에서 높은 광택도를 나타내었다. 기질의 경우, EG강판이나 primer가 처리된 강판에 비해 GI강판이 더 좋은 광택도를 보여주었다. 상기 공정 변수에 대한 연구를 통해 광택도 향상을 위해 사용되는 첨가제 없이도 $20^{\circ}$ 광택도 95 GU의 최대값을 $60^{\circ}$ 광택도는 120 GU의 광택도를 얻을 수 있었다.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2002년도 학술발표회 발표논문집
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• pp.205-208
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• 2002

This study is performed to examine the flowability and filling ability of steel fiber reinforced high performance concrete. For the estimation of the flowability and filling ability, slump flow, box height difference and L-shape filling appearence are measured and compared. The test result shows that the slump flow is $60{\pm}5cm$ to make no difference with containing steel fiber, box height difference is increased with increasing steel fiber and L-shape filling appearence is to bad with increasing steel fiber. But, proper containg of steel fiber is considered to be applied for high performance concrete without decreasing of slump flow and filling ability.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제55권12호
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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.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2007년도 추계학술대회 논문집
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• pp.215-222
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• 2007

Coating of Hot-dip galvannealed steel consists of various Fe-Zn intermetallic compounds. Since the coating is hard and there for is very brittle, the surface of steel sheet is easy to be ruptured during second manufacturing processing. This is called as powdering. In addition, forming equipment might be polluted with debris by powdering. Therefore, various research have been carried out to prohibit powdering fur improving the quality of GA steel. This paper carried out finite element analysis combined with damage model which simulate the failure of local layer of hot-dip galvannealed steel surface during v-bending test. Since the mechanical property of intermetallic compound was unknown exactly, we used the properties calculated from measurements. The specimen was divided into substrate, coating layer and interface layer. Local failure at coating layer or interface layer was simulated when elemental strain reached a prescribed strain.

• Journal of Welding and Joining
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• 제31권2호
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• pp.49-56
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• 2013

We have investigated traits of clad metals in hot-rolled clad steel plates, sensitization and mechanical properties of STS 316 steel plate and carbon steel(A516). Clad steel plates were butt-weld by SAW+SMAW, and with the time of heat treatment as the variable, heat treatment was conducted at $625^{\circ}C$, for 80, 160, 320, 640, 1280 minutes. As a way to evaluate it, sectioned weldments and external surfaces were investigated to reveal the degree of sensitization by mechanical property, etching and those of EPR test, results were compared with it. In short, the purpose of this study is suggesting some considerations in developing on-site techniques to evaluate the sensitization of stainless steels.

• 교육시설
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• 제6권4호
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• pp.16-23
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• 1999

The thermal and condensation performance of steel stud walls are monitored in steel-framed schools of Ee-Wol Elementary School and kindergarten using temperature and humidity sensors installed. The monitoring process carried out during the summer and winter period, shows decrement effect of the external heat flow to be quite remarkable and excellent. And steel stud walls provides a highly efficient time-lag effect in spite of its light weight property, with 30 minutes to 4 hours time-lag for external heat flow, which variation mainly depends on its location of each part of the wall. Any condensation phenomena are not observed in either external or internal surfaces.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2005년도 춘계학술대회 논문집
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• pp.313-316
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• 2005

In the present study, Bauschinger effect was investigated for the micro-alloying forging steel which has been developed for about 30 years ago to save energy consumption by eliminating the heat treatment processes in the forging industry. The micro-alloying steels used fur cold forging industry mainly aim to replace the usual carbon steel. With the conventional carbon steels, all the deformation history can be eliminated after the final heat treatment(quenching and tempering). In the case of micro-alloying forging steels, however, the prior deformation history should be taken into consideration to meet the mechanical property requirement since the microstructure of micro-alloying steels might exhibit the Bauschinger effect, which was not needed to consider in the case of conventional carbon steel having quenching and tempering treatment. In the present study, the reverse loading tests were carried out to determine the Bauschinger effect of micro-alloying steel which composed of ferrite and cementite phases.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2004년도 추계 학술발표회 제16권2호
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• pp.781-784
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• 2004

Method of Steel plate reinforced by fiber sheet is advantageous in the secure loading facility. For this method are a light weight and a high strength, the thickness of steel can be reduced Effects of composite system are depreciated when the thickness of steel is thin. This is the result of the difference of ductility ratio with steel plate. Steel plate reinforced by fiber sheets confirms the ability of transformation. This is the result of the property of steel materials Steel plate reinforced by fiber sheet didn't display an enough performance when theadhesives are epoxy rosin. This is the result of the slide of the surface of stee1. The adhesive ability is varied by the number and span of anchor bolts. There wasn't happening the separation between steel and epoxy. Thus the method used in combination with anchor and epoxy is best excellent. This is the result of the upward of accumulation effects Shearing force is in proportion to the number of bolts. But the ability of shearing force per one bolt is reducing. Thickness of steel plate reinforced by fiber sheet must be designed so that steel is endure before concrete is wreck.