• Title/Summary/Keyword: 부식 방지

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Evaluation on Performance of Surface Protectors for Protecting Reinforced Concrete Structures (철근 콘크리트 구조물을 보호하기 위한 표면 보호재의 성능 평가)

  • An, Young-Ki;Jang, Suk-Hwan;Chung, Young-Jun;Nam, Yong-Hyuk
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.9 no.1
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    • pp.217-223
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    • 2005
  • This study is on the evaluation of three kinds of surface protectors for protecting reinforced concrete against corrosion of reinforcing steel by chloride attack and carbonation. In this study, the test has been carried out on the performance of specimens applied with surface protectors for anti-corrosion and anti-carbonation. The result showed that specimens applied with the three kinds of surface protectors, were excellent in resistance to the corrosion of reinforcing steel and carbonation. Especially the specimen applied with finish coating in conjunction with hydrophobic primer showed great reduction in the corrosion of reinforcing steel and carbonation.

Surface and Corrosion Protection Properties of Fluorine Doped PVDF by Plasma Fluorination (플라즈마 불소화에 의해 제조된 불소 도핑 PVDF의 표면 및 부식방지 특성)

  • Kim, Seokjin;Lim, Chaehun;Kim, Daesup;Lee, Young-Seak
    • Applied Chemistry for Engineering
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    • v.32 no.6
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    • pp.653-658
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    • 2021
  • Polyvinylidene fluoride (PVDF) is a promising coating material because of its outstanding processability. The PVDF coating, however, has limitations in anti-corrosion application due to its weak hydrophobicity compared to that of other fluoropolymers. In this study, plasma fluorination was performed using carbon tetrafluoride (CF4) gas to improve anti-corrosion properties of PVDF. The fluorine content and hydrophobicity of PVDF were investigated in different CF4 flow rates, followed by the determination of anti-corrosion properties. The fluorine content on the surface of the PVDF film increased by up to 46.70%, but the surface free energy was independent of CF4 flow rate. Meanwhile, the surface roughness of the PDVF film tended to increase by up to 150% and then decrease with increasing CF4 flow rate. It is considered that the plasma fluorination affects the surface free energy due to the introduction of fluorine functional groups and surface etching. In addition, the degree of corrosion of the PVDF-coated Fe plate was significantly reduced from 49.2% to 19.0% compared to that of the uncoated Fe plate. In particular, the degree of corrosion of the fluorinated PVDF-coated Fe plate was 13.6%, which was 28.4% lower than that of the PVDF-coated Fe plate, showing improved anti-corrosion protection.

Corrosion and Strength Changes of Agricultural Steel Pipes Elapsed 20 Years under the Greenhouse Environment (온실 환경 하에서 20년 경과된 농업용 강관의 부식 및 강도변화)

  • Nam, Sang-Woon;Ryu, Hee-Ryong;Choi, Man-Kwon;Shin, Hyun-Ho
    • Journal of Bio-Environment Control
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    • v.29 no.2
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    • pp.196-201
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    • 2020
  • In order to increase the durability of the pipe framed greenhouse, galvanized steel pipes with four corrosion protection treatments were installed in the greenhouse. After 20 years, experiments on surface corrosion and strength change were conducted. Control (untreated) pipes exposed in the atmosphere showed a 1.3% reduction in strength, but little difference from other treatments. The strength of heavy protective coating pipes buried in the ground decreased by 0.6%, showing little change, but untreated pipes decreased by 15.7%. And antirust paint and asphalt coating pipes decreased by 4.2~4.4%. Pipes exposed in the atmosphere did not show severe corrosion in all samples. There was no change in heavy protective coating pipes, and no rust was found in antirust painting pipes either and there was only slight discoloration. Asphalt coating pipes discolored black and some rust was found, and untreated pipes were rusted by 20~30% of the surface. However, untreated pipes buried in the ground were completely rusted, and asphalt coating pipes were rusted by 80~90% of the surface. Antirust painting pipes were rusted by 20~30%, and heavy protective coating pipes did not change almost. The heavy protective coating treatment showed a clear corrosion protection effect even in the parts buried in the ground, and the antirust painting treatment also showed some corrosion protection effect. Therefore, it is judged to be applicable to the field of pipe framed greenhouses.

Corrosive control of the water produced by SWRO and Application to small dimensional Pilot Plant (SWRO 생산수의 부식성 제어를 위한 목표 수질 연구 및 소규모 Pilot Plant 적용)

  • Kim, Min-Chul;Hwang, Kyu-Won;Woo, Dal-Sik;Yoon, Seok-Min;Moon, Jung-Gi;Kwak, Moung-Hwa
    • Proceedings of the KAIS Fall Conference
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    • 2009.12a
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    • pp.1042-1045
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    • 2009
  • 역삼투식 해수담수화 (Sea Water Reverse Osmosis, SWRO) 공정에 의한 생산수는 pH가 낮고, 해수 내 존재하는 경도성분인 Ca, Mg 이온이 대부분 제거되기 때문에 상대적으로 매우 강한 부식성을 지니고 있다. 이를 음용수 및 공업용수로 이용 시 설비 및 배관계통에 심각한 부식문제를 유발할 수 있으며, 이를 방지하기 위한 처리공정과 부식성 제어 기술의 지속적인 개발이 요구되는 실정이다. SWRO 1단으로 처리 시 생산수의 전기전도도는 $150{\mu}S/cm$ 정도의 범위를 보이며, 2단 SWRO 과정을 거칠 시 전기전도도는 $100{\mu}S/cm$ 이하의 범위를 나타내는 것으로 알려져 있다. 본 연구에서는 SWRO 2단 처리수를 가정한 $20{\mu}S/cm{\sim}25{\mu}S/cm$ 범위의 전기전도도를 지닌 물을 실험 원수로 사용하여, 기존 방식제의 성분과 생산수의 특성을 고려한 효율적인 알칼리성 수처리제를 적용하고 그에 대한 부식성 제어 연구를 수행하였다. SWRO 생산수를 대상으로 부식방지기술을 개발하기 위해서는 부식제어와 관련된 수질 인자인 pH, 칼슘경도, 알칼리도의 조절과 LSI(Langelier Saturation Index)를 설정하는 것이 무엇보다도 중요하다. 본 연구에서는 해수담수화 공정의 생산수를 음용수 및 공업용수로 이용하기 위한 목표 수질을 pH 7.5~7.8, LSI 0 이상, 부가적으로 전기전도도는 $250{\mu}S/cm$ 이하로 설정하였으며, 연구목표 수질을 달성할 수 있는 부식억제제 및 알칼리성 수처리제의 적용을 통해 목표 수질에 대한 설정 근거를 마련하고자 하였다.

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