• Title/Summary/Keyword: Corrosion and Anti-corrosion

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EVALUATION OF FLEXURAL BOND PERFORMANCE IN R.C BEAM USING 3-TYPES ANTI-CORROSION COATINGS (철근방식을 위한 도포제 종류에 따른 R.C 보의 휨 부착성능 평가)

  • 이태규;이웅종;김종우;이종렬;신도철
    • Proceedings of the Korea Concrete Institute Conference
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    • 1995.10a
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    • pp.129-133
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    • 1995
  • The purpose of this study is to evaluate the flexural bond performance in beam using 3-types anti-corrosion coatings. For the test. we used $15\times\times20\times110cm$ R.C beams, in which the epoxy, the red lead, and the cementitious anti-corrosion coating re-bars used. The results of test using these 3-type anti-corrosion coatings are shown that the flexural bond performance of cementitious anti-corrosion coating rebar in R.C beam is superior to other anti-corrosion coatings rebars.

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Self-healing Coatings for an Anti-corrosion Barrier in Damaged Parts

  • Cho, Soo Hyoun
    • Corrosion Science and Technology
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    • v.8 no.6
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    • pp.223-226
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    • 2009
  • Polymer coatings are commonly applied to metal substrates to prevent corrosion in aggressive environments such as high humidity and under salt water. Once the polymer coating has been breached, for example due to cracking or scratches, it loses its effectiveness, and corrosion can rapidly propagate across the substrate. The self-healing system we will describe prevents corrosion by healing the damage through a healing reaction triggered by the actual damage event. This self-healing coating solution can be easily applied to most substrate materials, and our dual-capsule healing system provides a general approach to be compatible with most common polymer matrices. Specifically, we expect an excellent anti-corrosion property of the self-healing coatings in damaged parts coated on galvanized metal substrates.

A Simulation Case Study on Impact Safety Assessment of Roadside Barriers Built with High Anti-corrosion Hot-dip Alloy-coated Steel (용융합금도금 강판 적용 노측용 방호울타리 충돌 안전성 평가 해석 사례 연구)

  • Noh, Myung-Hyun
    • Journal of the Korean Society of Safety
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    • v.31 no.2
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    • pp.83-89
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    • 2016
  • As the world's industrial development quickens, the highways and regional expressways have been expanding to serve the logistics and transportation needs of people. The burgeoning road construction has led to a growing interest in roadside installations. These must have reliable performance over long periods, reduced maintenance and high durability. Steel roadside barriers are prone to corrosion and other compromises to their functionality. Therefore, using high anti-corrosion steel material is now seen as a viable solution to this problem. Thus, the objective of this paper is to expand the scope of applications for high anti-corrosion steel material for roadside barriers. This paper assesses the impact safety such as structural performance, occupant protection performance and post-impact vehicular response performance by a simulation review on roadside barriers built with high strength anti-corrosion steel materials named as hot-dip zinc-aluminium-magnesium alloy-coated steel. The simulation test results for the roadside barriers built with high strength anti-corrosion steels with reduced sectional thickness meet the safety evaluation criteria, hence the proposed roadside barrier made by high strength and high anti-corrosion hot-dip zinc-aluminium-magnesium alloy-coated steel will be a good solution to serve safe impact performance as well as save maintenance cost.

Evaluation of Life Time for Anti-Corrosive Methods for Marine Steel Sheet by Cyclic Corrosion Test (실내 가속부식시험을 통한 해양 강관합성 말뚝의 방식 기법 수명 평가)

  • Park, J.W.;Lee, J.G.;Lee, K.W.;Kim, J.H.;Jung, M.K.;Lee, J.H.
    • Corrosion Science and Technology
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    • v.8 no.6
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    • pp.243-250
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    • 2009
  • When a steel sheet pipe applied to marine environment, an anti-corrosive coating should be treated to obtain long-term life-time for steels, especially, splash zone. Although anti-corrosive property of coatings is required to be tested in real marine environment, it is difficult because of long test time such as 20 years or more time. Therefore, we used cyclic corrosion tester in a laboratory, which has similar conditions with salt-dry-wet process such as real marine environment. Anti-corrosive properties of the coatings and two steels were tested their anti-corrosive properties under cyclic corrosion test conditions(KS D ISO 14993) and the results were compared with estimate life-time in real marine environment. According to cyclic corrosion test, accelerated corrosive factor of each anti-corrosive coating was investigated accelerated corrosive factor from impedance with EIS method. Accelerated corrosive factor of type SS400 carbon steel and A690 was also investigated their accelerated corrosive factor from the regression curves of weigh loss results. One of the anti-corrosive coatings showed about 50 years life-time compared with standard sample life-time. Carbon steel SS400 showed from 0.1 mm/yr to 0.06 mm/yr as its corrosion rate.

The Experimental Study on Performance of Cementitious and Organic Anti-corrossion Coatings (시멘트계 및 유기계 도포재료의 방청성능에 관한 실험적 연구)

  • 신도철;이종열;박정순;오희갑;이태규
    • Proceedings of the Korea Concrete Institute Conference
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    • 1995.10a
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    • pp.150-154
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    • 1995
  • The purpose of this study is to evalute the mechanical and the anti-corrosion characteristics of cementitious, organic coatings on steel plates. Tests are performed according to KS M 5331, 5250, etc'. For the test, we used water based epoxy, Tar epoxy, the red lead, and cementitious anti-corrosion coatings. The results of adhension tests satisfying the requirements in relevant standards The impact test shown that the impact test shown that the impact resistance of cementitious anti-corrosion test, rred lead, epoxy, cementitiouse show good corrosion resistance.

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Corrosion and Sliding Properties of the Nickel-Based Alloys for the Valve Seats Application

  • Honda, Tadashi
    • Corrosion Science and Technology
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    • v.7 no.2
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    • pp.92-98
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    • 2008
  • This paper describes the experiments of the corrosion and the sliding tests of the nickel-based alloys for the gate valve seating materials used at high pressure and temperature. The general corrosion rates and IGC susceptibility are tested in pressurized water at 533 K and 575 K and in Strauss test solution. The sliding tests have been done in pressurized water at 293 k, 473 K and 573 k. The alloys containing above 10% chromium may have the anti-corrosion properties that could be applied to the valve seats for the power plants. The good sliding performance and the good pressure tightness are obtained when the disc specimens that have hardness 500 to 600 Hv combined with the seat specimens that have hardness 250 to 410 Hv containing about 40 percent of iron. The large size gate valves sliding tests have certified the test results. The anti-wear properties of the seat alloy and the anti-IGC susceptibility of the disc alloy could be improved by the addition of silicon and niobium, respectively.

The Study on Effect of Collision Safety by Corrosion of Body Structure (차체구조물의 부식이 충돌안전도에 미치는 영향에 관한 연구)

  • 박인송;정태용
    • Transactions of the Korean Society of Automotive Engineers
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    • v.10 no.4
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    • pp.141-148
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    • 2002
  • Repair were made for front pillar, center pillar and side-step panel for lightweight vehicles with head-on and 40% off-set collision of 15 km/h in a RCAR standard. The salt dilution was sprayed and the compression tests were performed for vehicles with and without anti-corrosional treatment after repair. After 764 hours of salt-dilt sprayed test without using anti-corrosion, the mean penetration depth fur corrosion was shown to be 58% of the thickness. The resulyed decrease in bending stiffness by 10∼20% can cause reduction of the residual life and crash-absorption capability for damaged vehicles. The corrosoin safety tests showed that the anti-corrosional treatment should be made to improve the safety characteristics for a or damaged car.

The Effect of $Bi(OH)_3$ on Corrosion-Resistant Properties of Automotive Epoxy Primers

  • Yang, Wonseog;Min, Sungki;Hwang, Woon-suk
    • Corrosion Science and Technology
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    • v.7 no.6
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    • pp.370-374
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    • 2008
  • In this study, we evaluated anti-corrosion properties of both commercial unleaded and lead epoxy primer for automotive substrate before applying to actual painting lines by salt spray test, and cyclic corrosion test, potentiodynamic test and electrochemical impedance spectroscopy. The difference in the corrosion resistance between automotive epoxy primers contained $Bi(OH)_{3}$ and leaded one was investigated. And it was also discussed the effect of zinc phosphate pretreatment to the epoxy primers. The specimen coated epoxy primer contained $Bi(OH)_{3}$ showed 0.5 V higher corrosion potential than that of bare steel. The result of salt spray test did not indicate remarkable difference of corrosion resistance in all specimens above $10{\mu}m$ thickness up to 1200 hours. In the cyclic corrosion test, epoxy primers contained $Bi(OH)_{3}$ on phosphated substrate performed good corrosion properties until 800 hours. The epoxy primer contained $Bi(OH)_{3}$ performed the equivalent corrosion resistance as leaded coating on phosphated steel, but slightly inferior to that of leaded on bare steel. These results show that the pre-treatment of zinc phosphate is effective as well as pigment changing in performing anti-corrosion properties in automotive bodies.

Coating Performance of SiO2 / Epoxy Composites as a Corrosion Protector

  • Rzaij, Dina R.;Ahmed, Nagham Y.;Alhaboubi, Naseer
    • Corrosion Science and Technology
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    • v.21 no.2
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    • pp.111-120
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    • 2022
  • To solve the corrosion problem of industrial equipment and other constructions containing metals, corrosion protection can be performed by using coating which provides a barrier between the metal and its environment. Coatings play a significant role in protecting irons and steels in harsh marine and acid environments. This study was conducted to identify an anti-corrosive epoxy coating for carbon steel composite with 0.1, 0.3, and 0.5 wt% concentrations of nanoparticles of SiO2 using the dip-coating method. The electrochemical behavior was analyzed with open circuit potential (OCP) technics and polarization curves (Tafle) in 3.5 wt% NaCl and 5 vol% H2SO4 media. The structure, composition, and morphology were characterized using different analytical techniques such as X-ray Diffraction (XRD), Fourier Transform Infrared spectrum (FT-IR), and Scanning Electron Microscopy (SEM). Results revealed that epoxynano SiO2 coating demonstrated a lower corrosion rate of 2.51 × 10-4 mm/year and the efficiency of corrosion protection was as high as 99.77%. The electrochemical measurement showed that the nano-SiO2 / epoxy coating enhanced the anti-corrosive performance in both NaCl and H2SO4 media.

Anti-Corrosion Characteristics of WC-based Alloy Coatings Fabricated by HVOF Process - Polarization Characteristics in Alkaline Solution - (HVOF 용사법에 의해 제조된 WC계 합금 코팅층의 방식특성(II) - 알칼리 용액에서의 분극특성 -)

  • Kim, Tae-Yong;Kim, Yeong-Sik;Kim, Jae-Dong
    • Journal of Power System Engineering
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    • v.18 no.6
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    • pp.40-44
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    • 2014
  • The purpose of this paper is to investigate polarization characteristics of WC-based alloy coatings in alkaline solution. The coatings were fabricated with WC-CrC-Ni, WC-Co-Cr and WC-Co composite powders by HVOF process. Corrosion tests of coatings and substrate were carried out using potentiostat/galvanostat at solution with pH 8 and pH 13. Corrosion potential(Ecorr) and corrosion current density(Icorr) could be studied from polarization curve, and corrosion behavior was analyzed by SEM and EDS. WC-Co-Cr coating and WC-CrC-Ni coating showed more favorable anti-corrosion characteristics than WC-Co coating and substrate at solution with pH 8 and pH 13.