• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2002년도 가을 학술발표회 논문집
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• pp.409-414
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• 2002

This study is intended to develop the self water proof admixture for durability concrete by anti-corrosion inhibitor. Chloride induced corrosion of reinforcement is one of the main factor which cause the deterioration of concrete structure. When the substitute anti-corrosion agents for a part of self waterproofing agent, the corrosion-proof increases for the increased water proofing capacity. And proper self waterproofing agent by cement weight in concrete was generally positive effect to concrete compressive strength, slump, freezing and thawing resistance. Also, permeability and absorption show a straight decrease when self waterproofing agent is added.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2005년도 추계 학술논문 발표대회
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• pp.33-38
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• 2005

It is applied in the high quality equipment construction by introduction of this high duality treating technology (ozone treating, activated carbon treating, high quality oxidation treating, UV treating etc.)waterproofing or corrosion proof method caused secondary economy damage of operation discontinuance and high quality treating equipment for applying existent waterproofing method that corrosion proof ability (ozone resistance performance, chemical resistance etc.) and abrasion resistance performance by comprehension insufficiency of user and designer. Therefor, In this study, we will analyze problem of waterproofing and corrosion material of existing construction application by high quality treating, and measure physical performance change by various condition. It is required to waterproofing and corrosion system and application of the field valuation.

• 한국산학기술학회논문지
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• 제16권4호
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• pp.2391-2400
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• 2015

내후성 강재는 대기환경에서 내식성이 우수하여 강교량의 재료로 많이 사용되고 있다. 그러나 내후성 강은 해수와 가까운 지역, 음지 및 습도가 높은 환경에서는 안정된 녹층이 형성되지 않고, 일반녹이 발생하고 있다. 따라서 열악한 대기환경을 가지는 일본에서는 무도장으로 사용하지 않고, 녹안정화 처리를 하고 있는 상황이다. 그러나 국내에서 건설된 내후성 강은 대부분 무도장으로 건설되었고, 건습의 주기적인 반복이 일어나기 어려운 밀폐형 박스거더형으로 건설되었다. 특히, 한강수변위에 건설된 강교량의 경우, 수분의 증발, 온도차에 의한 결로 및 우수에 의한 체수 등으로 내후성강의 부동태 피막형성에 해로운 영향을 미치고 있다. 이에 따라, 본 연구에서는 상수도 보호구역에 무도장 내후성 강으로 건설된 교량의 밀폐형 박스거더 내부의 부식 특성을 분석하기 위하여, 육안에 의한 관찰, 셀로판 테이프 시험, 강재 두께 측정, 표면 부식 전위측정, 채취한 녹의 전자현미경 분석 및 X선 회절 분석을 실시하였다. 분석을 통하여, 밀폐형 박스거더 내부에서 불안정녹층이 관찰되었으며, 특히, 상부 및 하부 플랜지의 경우 우수에 의한 체수, 결로 및 제설제에 의한 영향 등으로 부식 정도가 심하게 관찰되었다.

• Nuclear Engineering and Technology
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• 제49권7호
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• pp.1463-1471
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• 2017

In order to monitor the pipe thinning caused by flow-accelerated corrosion (FAC) that occurs in coolant piping systems, a shear horizontal ultrasonic pitch-catch waveguide technique was developed for accurate pipe wall thickness monitoring. A clamping device for dry coupling contact between the end of the waveguide and pipe surface was designed and fabricated. A computer program for multi-channel on-line monitoring of the pipe thickness at high temperature was also developed. Both a four-channel buffer rod pulse-echo type and a shear horizontal ultrasonic waveguide type for high-temperature thickness monitoring system were successfully installed to the test section of the FAC proof test facility. The overall measurement error can be estimated as ${\pm}10{\mu}m$ during a cycle from room temperature to $200^{\circ}C$.

• Tribology and Lubricants
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• 제16권3호
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• pp.173-181
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• 2000

Friction, wear and corrosion characteristics of various MoS$_2$ bonded film lubricants were investigated to apply them to automotive wheel joints. MoS$_2$ bonded film lubricants were formulated by combinations of several additives and binders, and they were coated onto the pre-treated surfaces of specimens. Friction and wear characteristics were evaluated with Falex pin & vee-block test and LFW-1 block-on-ring test. For the corrosion resistant characteristics of the films, salt solution spray corrosion tests were performed. Results showed that MoS$_2$ bonded films containing both inorganic and organic corrosion-resistant additives yielded a synergy effect on anti-corrosion resistance. Also, binders having the better water-proof and thermal stability showed the lower friction and higher corrosion resistance.

• 전기학회논문지
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• 제58권9호
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• pp.1764-1768
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• 2009

As the demand of electric power is increasing rapidly, the need of the compact and light electric power device is also increased. Copper clad aluminum (CCA) is newly proposed electrical conductor, because of its light-weight and low-cost characteristics, to replace the existing conductor made of copper. This paper presents the salt-proof characteristics of the copper clad aluminum (CCA) to certificate long time safe operation of the newly proposed electrical conductor. The two types of the CCA conductor were tested in the neutral salt spray tester. The experimental results of two types of the CCA with salt spray were presented in this paper. The results comprise resistance measured data, micro picture of the selected surface, and component measured data according to the elapsed time. The period of the experiment was 1,000 hours. There was no evidence to show the corrosion of CCA during the whole period of the experiments.

• Corrosion Science and Technology
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• 제3권4호
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• pp.154-160
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• 2004

The Sulfide Stress Corrosion Cracking (SSCC) resistance of structural steels is one of the critical concerns for the operators, material designers, and fabricators of oil-field equipment, especially treating sour gas (H2S) containing fluids. As far as its fabricators concerned, the systematic care of welding parameters should be taken to obtain comparable SSCC resistance of their weldment to that of its base material. In this respect, every different type of welding joint design for this use should be verified to be SSCC-proof with relevant test procedures. In this study, the welding parameters to secure a proper SSCC resistance of steel pipe's weldments were reviewed on the Welding Procedure Qualification Records (WPQR), which had been employed for actual fabrication of an offshore structure for oil and gas production. Based on this review, a guideline of welding parameters, such as, heat input, welding consumable for Y.S. 65 ksi class steel pipe material is proposed in terms of the NACE criteria for SSCC resistance.

• 보존과학연구
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• 통권7호
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• pp.48-55
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• 1986

The gold crown unearthed from the ancient tombs at Imdang-dong, Kyongsan-gun, Kyongsangbuk-do was in a state of severe corrosion that its original pattern couldn't be identified. Therefore, for the conservation of the relics, the following methods are employed :1. With 10% formic acid are used for the elimination of the bronze-rust and then plated them with gold.2. As a rust-proof treatment, 1% Benzotriazole is used for stem corrosion as well3. For protection and reinforcement of the surface of the relics, 30% incralac agentsare used.4. Pieces of fragments are bonded together by cyanoacrylate and on the backside are coated partially with Araldite for the reinforcement of the glass-wool.5. Silica-gels are kept into the acryl box for perfect maintenance.

• Nuclear Engineering and Technology
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• 제54권1호
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• pp.186-192
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• 2022

Flow accelerated corrosion (FAC) is a type of pipe corrosion in which the pipe thickness decreases depending on the fluid flow conditions. In nuclear power plants, FAC mainly occurs in the carbon steel pipes of a secondary system. However, because the temperature of a secondary system pipe is over 150 ℃, in situ monitoring using a conventional ultrasonic non-destructive testing method is difficult. In our previous study, we developed a waveguide ultrasonic thickness measurement system. In this study, we applied a waveguide ultrasonic thickness measurement system to monitor the thinning of the pipe according to the change in pH. The Korea Atomic Energy Research Institute installed FAC-proof facilities, enabling the monitoring of internal fluid flow conditions, which were fixed for ~1000 h to analyze the effect of the pH. The measurement system operated without failure for ~3000 h and the pipe thickness was found to be reduced by ~10% at pH 9 compared to that at pH 7. The thickness of the pipe was measured using a microscope after the experiment, and the reliability of the system was confirmed with less than 1% error. This technology is expected to also be applicable to the thickness-reduction monitoring of other high-temperature materials.

• 한국해양공학회지
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• 제27권2호
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• pp.33-38
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• 2013

In the past, a very popular method for reducing the corrosion on zinc involved the use of chemical conversion layer coatings based on $Cr^{+6}$. However, there is an important problem with using chromium salts as a result of restrictive environmental protection legislation. This study investigated the optimum condition for galvanized steel using an organic/inorganic solution with a Ti composition. In the case of a fixed heat treatment time, the corrosion resistance values of LR-0727(1) and LR-0727(2) were improved as the heat treatment temperature increased, and the optimum minimum temperature decreased with the heat treatment time. At the optimum heat treatment condition of two coating solutions, the heat treatment time of the LR-0727(1) solution was shorter than LR-0727(2) for the same heat treatment temperature. LR-0727(1) coated specimens did not show desquamation, and all of the specimens showed a good adhesive property. In contrast, in the case of the LR-0727(2) coated specimens, desquamation arose. Therefore, the adhesive property of LR-0727(1) was superior to that of LR-0727(2). The pencil hardness had a 3H average for all of the coating solutions and heat treatment conditions. In the case of a corrosion resistance test with boiling water, the coated specimens of LR-0727(1) were discolored, but LR-0727(2) was not. Finally, LR-0727(1) was more moisture proof than LR-0727(2).