• Corrosion Science and Technology
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• 제15권6호
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• pp.290-296
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• 2016

This study was conducted in order to examine the effect of burn damage and the resultant anti-corrosion performance. The breakdown and defect of the paint film caused by burn damage are considered to affect not only the macroscopic appearance but also the adhesive force and the anti-corrosion performance of the paint film. The material of the paint film was epoxy paint that is used most widely for heavy-duty coating, and in order to induce burn damage, heat treatment with a torch was applied to the other side of the paint film. Surface and chemical structure changes according to aging were analyzed using FE-SEM and infrared absorption spectroscopy, and variation in the anti-corrosion performance was analyzed through the AC impedance test.

• 한국해양공학회지
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• 제23권4호
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• pp.64-68
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• 2009

It has been observed that coated steel structures deteriorate more rapidly than the designed lifetime due to acid rain caused by air pollution, etc. Therefore, improving the corrosion resistance of anti-corrosive paint is very important in terms of safety and the economic point of view. In this study, the corrosion resistance of five kinds of anti-corrosive paints, including the Acryl, Fluorine, and Epoxy resin series, were investigated with electrochemical methods, such as corrosion potential measurements, polarization curves, diffusion limiting current density, etc. As a result, the corrosion resistance of the F101 specimen with the fluorine resin series was found to be superior to the other specimens, while E100 with the epoxy resin series also showed a somewhat good corrosion resistance. Furthermore, it was observed that the amount of water and oxygen entering the inner side of a painted film increased with an increase in immersion time, irrespective of the kind of resin series. However, the oxygen diffusion limiting current density of a specimen with good corrosion resistance was relatively decreased compared to other specimens, because of the difficulty of oxygen diffusion penetrating to the inner side of the film. Consequently it is suggested that we can qualitatively evaluate the corrosion resistance of an anti-corrosive paint by measuring the diffusion limiting current density as an electrochemical method.

• 한국해양공학회지
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• 제21권3호
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• pp.65-70
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• 2007

There are many kinds of protection methods for marine structures, with varyingeconomical and environmental advantages. The coating protection method is being widely used in both continental and marine structures. In this study, by adding some additives, such as Zn powder(Zn), carbon black(CB) to epoxy anti-corrosive paint, the effect on the corrosion resistance was investigated throughan electrochemical method. The additive of Zn(20)+CB(10) showed the lowest passivity current density. Polarization resistance in both cyclic voltammogram and impedance measurement of an additive of Zn(20)+CB(10) was also the largest value, compared to other additives. Furthermore, rusting and bubbling was not observed on the surface of the test specimen with the additive of Zn(20)+CB(10), compared to other specimens. It is suggested that the corrosion resistance of the anti-corrosive paint can be improved by using some additives.

• Journal of Advanced Marine Engineering and Technology
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• 제33권3호
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• pp.387-394
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• 2009

It has been observed that coated steel structures are rapidly deteriorated than designed lifetime due to acid rain caused by air pollution etc.. Therefore improvement of corrosion resistance of anti-corrosive paint is very important in terms of safety and economic point of view. In this study corrosion resistance for five kinds of anti-corrosive paints including acryl, fluorine and epoxy resin series were investigated with electrochemical methods such as corrosion potential, polarization curves, impedance and cyclic voltammogram measurements etc.. There were somewhat good relationships between values measured by electrochemical methods such as corrosion current density obtained by cathodic and anodic polarization curves, value of impedance estimated with AC impedance, and polarization resistance on the cyclic voltammogram, for example, corrosion current density was decreased with increasing of values of impedance and polarization resistance on the cyclic voltammogram. However their relationships between corrosion current density and corrosion potential were not well coincided each other. Consequently it is considered that although a corrosion potential of F101 of fuoric resin series shifted to negative direction than other anti-corrosive paints, its corrosion resistance, indicating on the cathodic and anodic polarization curves, AC impedance curves and cyclic voltammogram, was the most superior to other paints, whereas A100 containing arcylic resin showed a relatively poor corrosion resistance compared to other paints.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2005년도 춘계 학술기술논문발표대회 논문집
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• pp.113-117
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• 2005

The ceramic metal resin paints for waterproof and anti corrosion is not long history in development of materials even many actual result. So far, no standard have been given to construction and maintenance method, Quality and property, it is real state that cannot afford to proper quality control in job site or production. This study has been test for the ceramic metal resin paints for water and anti corrosion, as the result, it have proper performance of job site and mechanical performance of compare to other existing. In particular, tensile strength indicates more high about $14.1N/mm^2$ than epoxy resin paints, and in elongation per unit length is more high It is shows having better adhesive strength than epoxy resin paint for crack on the concrete structure. Moreover, The ceramic metal paint for water and corrosion proofing have to have main performance is watertightness and resistance for external impact, chloride ion permeation, drinkable water elution.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2006년 창립20주년기념 정기학술대회 및 국제워크샵
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• pp.173-176
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• 2006

There are many kinds of protection methods for marine structures by using and environmental condition. Coating protection method, one of these methods is being widely adopted to both all ground and marine structures. In this study, by adding some additives such as Zn powder(Zn), carbon black(CB) to epoxy anti-corrosive paint, the effect to promote corrosion resistance was investigated with electrochemical method. Corrosion potentials with additives shifted to negative direction than no additive. However passivity current density increased than no additive except for Zn(20)+CB(10), especially, additive of Zn(20)+CB(10) showed the smallest passivity current density. Polarization resistance of Zn(20)+CB(10) by both cyclic voltammogram and impedance measurement was the largest value than other additives. And also surface phenomenon by adding Zn(20)+CB(10) was observed a good add condition not showing bubbling than other additives.

• Corrosion Science and Technology
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• 제13권1호
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• pp.15-19
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• 2014

Recently, anti-fouling paints which does not include the poison components such as tin(Sn), copper(Cu) have been increasingly developed in order to inhibit the environmental contamination of the sea water. Moreover, the wear ratios of these anti-fouling paints are very important problem to prolong their life time in economical point of view. In this study, five types of anti-fouling paints as self polishing type were investigated on the relationship between their polarization characteristics and wear ratios. It was verified that there was apparently a good relationship between the wear ratio and polarization characteristics, for example, the wear ratio increased with increasing the impedance ratio, and increased or decreased with the corrosion potential shifting in the negative or positive direction respectively. In addition, the wear ratio decreased with decreasing the corrosion current density. Consequently, it is suggested that we can qualitatively expect the wear ratio by only measuring the polarization characteristics. Therefore, before the examination of the wear ratio was actually carried out in the field, the evaluation of polarization property in the laboratory may give a available reference data for their developments.

• 한국표면공학회지
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• 제51권2호
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• pp.95-103
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• 2018

Recently, many types of constructional steels have been often exposed to under severe corrosive environments due to acid rain with increasing environmental contamination. In order to inhibit their corrosion in severe corrosive environments, a painting method has been widely applied to numerous constructional steels of land as well as marine. Therefore, development of paint having a good quality of corrosion resistance is considered to be very important. In this study, four types of anti-corrosive paints (AP: Phenol epoxy, AC: Ceramic epoxy, AT: Coal tar epoxy, AH: High solid epoxy) were coated to the specimens, and then, were immerged in various salt solutions (0.1, 0.3, 3, 6, 9 and 15% NaCl solutions) for 11 days. And, the corrosion resistance of these samples by effect of osmotic pressure with salt concentration was investigated with electrochemical methods such as measurement of corrosion potential, impedance and corrosion current density. The corrosion current densities of all samples (AC, AT and AH) submerged in 3% NaCl solution exhibited the smallest values compared to other salt solutions. However, in the case of lower values of salt solutions than 3% NaCl solution, the corrosion current density increased again because it makes easier for water, dissolved oxygen and chloride ion etc. to invade toward inner side of coating film due to increasing of the osmotic pressure than 3% NaCl solution, but in the case of higher values of salt solutions than 3% NaCl solution, the coating film is easily deteriorated due to high concentration of chloride ion rather than the osmotic pressure, which resulted in increasing the corrosion current density. In particular, the AC sample indicated the best corrosion resistance in 6% NaCl solution compared to other samples. Consequently, it is considered that the corrosion mechanism of the coated steel plate is completely different from bare steel plate, and the corrosion resistance of coating film by osmotic pressure and chloride ion depend on various types of epoxy of paint in NaCl solution.

• Corrosion Science and Technology
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• 제16권6호
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• pp.298-304
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• 2017

Coil spring steels from the automobile suspension part after field exposure for 10 years and those after anti-corrosion validation test in proving ground of 5,000 ~ 10,000 km were examined for corrosion damages. Partial loss of paint, accumulation of corrosion product, and cracking of paint and superficial material were observed. The surface and subsurface region of spring steels had compressive residual stress and high hardness by shot peening. The surface hardness values of the specimens were 620 ~ 670 Hv. They were 60 ~ 80 Hv higher than those of the samples taken from the middle part of the spring. The maximum compressive stress was -916 ~ -1208 MPa measured at depth of about $100{\mu}m$. Electrochemical impedance spectroscopy showed that the resistances of charge transfer and the paint layer of the spring steels ranged from several tens to millions ${\Omega}{\cdot}cm^2$. The resistance of the field samples was much higher than that of the proving ground samples used in this study, implying that the proving ground test condition would be more corrosive than the field environment.

• 한국산학기술학회논문지
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• 제20권5호
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• pp.7-12
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• 2019

군의 수상함정은 다수 해역에서 작전 업무 수행을 실시하며, 부식이 되기 쉬운 가혹한 환경에 노출되어 있다. 해군 운용 함정들은 부식을 방지하기 위하여 여러 가지 방법의 방식 기술을 적용하고 있으나, 캐비테이션에 의한 선저구조물에 부식 및 손상이 지속적으로 발생한다. 선체의 부식은 함 작전운용성능 저하 및 함 수명에 직접적인 영향을 미칠 수 있는 요소로서 함정 선체의 방식은 반드시 필요하다. 본 연구에서는 해군에서 운용중인 함형별로 사용하는 방청도료 자료를 수집 및 분석하여, 그 중 주 방청도료로 사용하고 있는 EH 2350과 미 해군에서 선저 구조물 보호를 위하여 사용하고 있는 특수도료인 금속보수제 DuraTough DL과 특성 비교 및 내마모성 시험을 통해 적합성 검증을 실시하였다. 객관적인 검증을 위하여 함이 해수 환경에 노출된 것으로 고려하여 마모 cycle과 마모 하중 조건을 다수 설정하여 검증을 실시하였다. 본 연구를 통하여 해군 수상함정에 일반적으로 적용되는 방청도료(EH 2350)의 적합성에 대한 신뢰성을 확보할 수 있을 것이다.