• Title/Summary/Keyword: 내후성강

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Proposed Prediction of Corrosion Loss for Weathering Steel Cladding in KIHO region using Multi-variable Analysis (기호지방 건축용 내후성강 외장재의 다변량 해석을 통한 부식량 예측식 제안)

  • Chung, Kyung Soo;Lee, Jae Sung;Chung, Jin An;Lee, Sung Eun
    • Journal of Korean Society of Steel Construction
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    • v.20 no.5
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    • pp.591-599
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    • 2008
  • Weathering steel has been widely used in bridges and cladding materials due to its superior atmospheric corrosion resistance. Actually, weathering steel has often been used in Korea as cladding material. However, the performance of the weathering steel in claddings has not been fully monitored. We conducted a field study on the performance of weathering steels and measured the quantity of corrosion loss on the weathering steel claddings in Korea. Based on the measured corrosion loss and weather (environmental) data, the equation to predict corrosion loss of weathering steels was proposed by using environmental factors in KIHO region in Korea. The proposed equation predicted very well the real corrosion losses of KIHO region.

Independent Cooling Controller for Temperature Control of High Strength and Atmosphere Corrosion Resisting Steel in Hot Strip Mills (고강도 내후성강의 온도제어를 위한 ICC 제어기 개발)

  • Park, Cheol Jae
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.39 no.3
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    • pp.327-335
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    • 2015
  • In this paper, we propose an independent cooling control (ICC) scheme for high strength and atmosphere corrosion resisting steel to obtain the desired temperature and properties along the longitudinal direction of the steel in the run-out table (ROT) process. A temperature model of the independent process is developed to divide the ROT into front and back sections. The control concept uses field data, problem analysis, and a time-temperature transformation diagram. The effectiveness of the proposed control is verified using simulation results under a temperature disturbance by the transformation in the middle of the ROT. The results of a hot strip mill field test show that the temperature control performance is significantly improved by the proposed control scheme.

Long-term corrosion-resistance of an uncoated weathering steel and its on-line and in-situ measurements (무도장 내후성강의 장기 내식성 및 그 현장즉시측정법)

  • Park, Jeong Real;Kim, Kyoo Young
    • Journal of Korean Society of Steel Construction
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    • v.16 no.4 s.71
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    • pp.415-423
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    • 2004
  • To investigate the long-term corrosion resistance of an uncoated weathering steel, an important outdoor constructional steel material, skyward surfaces of the weathering steel and a control steel initially exposed to rural and industrial atmospheres for 9 years were electrochemically tested in neutral artificial rain in terms of electrochemical potentials, impedances, and anodic potentiodynamic polarization curves. Their results were then discussed. A quite passive and stable rust layer to the artificial rain was well formed on the skyward surface of the weathering steel exposed to the industrial and rural atmospheres, and its corrosion rate in the artificial rain was measured to be about a low $3{{\mu}m}/y$. Continuous immersion of all the weathered surfaces in the artificial rain revealed the gradual degradation of the weathered corrosion layers on the steel, resulting in a cathodically controlled corrosion of the substrate steel by the electrochemical measurements. Alloy components of the weathering steel were found to retard the degradation of the weathered corrosion layers on the steel in the artificial rain. For better corrosion evaluation of the weathering steel, more electrochemical measurements of surfaces that have been exposed for more than 9 years to more closely simulated atmospheric waters are needed. These measurements are almost non-destructive and can provide online and in situ information on the corrosion rate, the development of corrosion and the conditions of rust layers on any interested surface and at any exposure time of the steel, so they can be effectively applicable to the corrosion evaluation of steel structures such as bridges, towers, and architectures by forming an electrochemical cell on an interested structural surface and by using a portable electrochemical instrument.

The study on the protection method from corrosion by the sealant injection on the unpainted weathering steel top flange outer surface of box girder (도장이 필요없는 내후성강 박스거더 상부 플랜지외부면 방식제 주입을 통한 방식공법 연구)

  • Song, Chang-Young
    • Corrosion Science and Technology
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    • v.13 no.4
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    • pp.139-144
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    • 2014
  • In corrosion-sensitive area of exsisting unpainted weathering steel bridge with closed box girder structure. there are some serious local corrosion problems because of rain water or dew water which can not be solved by conventional maintenance method. These problems must be technically controled because of the influence on the safety of bridge. This study is the first stage of developing the economic corrosion control manual for these local corrosion problems. Through the injecting experiment of tar sealant into the crevice of mock-up equipment, it was proofed that the corrosive sealant can be useful to corrosion control at crevice of corrosion sensitive area.

A Study on Corrosion Failure of a Weathering Steel Weldment with Various Applied Potentials in Acid-chloride Solution (산-염소이온 분위기의 인자전위에 따른 내후성강 용접부의 부식파괴에 관한 연구)

  • 최윤석;김정구;김종집;이병훈
    • Journal of Welding and Joining
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    • v.18 no.3
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    • pp.97-105
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    • 2000
  • The stress corrosion cracking(SCC) and hydrogen embrittlement cracking(HEC) characteristics of a weathering steel weldment were investigated in aerated acid-chloride solution. The electrochemical properties of weldment were investigated by polarization test and galvanic corrosion test. Weathering steel did not show passive behavior in the acid-chloride solution. Galvanic corrosion between the weld metal and the base metal was not observed because the base metal was anodic to the weld metal. The slow-strain-rate tests(SSRT0 were conducted at a constant strain rate o 7.87×{TEX}$10^{-7}${/TEX}/s at corrosion potential, and at potentiostatically controlled anodic and cathodic potentials. The weldment of weathering steel was susceptible to both anodic dissolution SCC and hydrogen evolution HEC.

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Application of Mössbauer Spectroscopy for Steel Industry (철강산업에 뫼스바우어 분광기법의 응용)

  • Oh, Sei-Jin
    • Journal of the Korean Magnetics Society
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    • v.16 no.1
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    • pp.51-59
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    • 2006
  • $M\"{o}ssbauer$ spectroscopy is one of the very powerful analytical methods for studying the steel properties. It is the most important advantage that the steel properties can be quantitatively analyzed by Mossbauer analysis. The quantitative analysis could provide various information about corrosion products, environmental condition, kind of steel, foreign element, particle size, etc. It can be also applied for the study of strength and phase of steel, as functions of the kind of steel and foreign elements.

Atmospheric corrosion rate and corrosivity categories of industrial metals in Asan area (아산지역에서 산업재료의 대기부식속도 측정)

  • Kim, Jin-Hyung;Lee, Jong-Kwon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.14 no.10
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    • pp.4653-4657
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    • 2013
  • The atmospheric corrosion rate were measured in Asan area for four years according to ISO 9224. The tested metals chosen as the most frequently used in industry, aluminum were copper, carbon steel, weathgering steel, and galvanized steel. The assessed corrosivity categories was 3 in average. The corrosivity categories of asan area was higher than typical rural area and even urban area, whereas it slightly lower than marine area. The results were discussed, specially as the regional climatic characteristics.

The anti-corrosion study on the corrosion-sensitive areas of unpainted weathering steel bridges with closed box girder(I) (밀폐 박스거더형 무도장 내후성강 교량의 부식취약부에 대한 방식대책 연구(I))

  • Song, Chang-young;Lee, Eui-Ho;Lee, Jea-Hyun;Park, Hyun-Chul;Choi, Jae-Suk;Noh, Young-Tae
    • Corrosion Science and Technology
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    • v.12 no.3
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    • pp.149-157
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    • 2013
  • In corrosion-sensitive areas of exsisting unpainted weathering steel bridges with closed box girder structures. there are some serious local corrosion problems because of rain water or dew water which can not be solved by exsisting maintenance methods. These problems must be controled technically because of bad. influence on the safety of bridge. This study is the first stage of developing the economic corrosion control manual for these local corrosion problems. Through the injection of tar sealant into the crevice of mock-up equipment, it was prooved that the corrosive sealant can be useful to corrosion control at crevice of corrosion sensitive area.

The anti-corrosion study on the corrosion-sensitive areas of unpainted weathering steel bridges with closed box girder(II) (밀폐 박스거더형 무도장 내후성강 교량의 부식취약부에 대한 방식대책 연구(II))

  • Song, Chang-Young;Lee, Eui-Ho;Lee, Jea-Hyun;Park, Hyun-Chul;Choi, Jae-Suk;Noh, Young-Tae
    • Corrosion Science and Technology
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    • v.12 no.4
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    • pp.191-197
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    • 2013
  • This study is the second stage of developing the corrosion control technical manual about unpainted weathering steel bridge with closed box girder structures. This paper contains selection of corrosive sealant to apply into crevice of upper flange, injecting test of sealant at mock-up equipment with various condition, evaluation of experiment result. Through the experiment of injection of sealants into crevice of mock-up equipment, it is proved that the tar sealant injecting corrosion control method is useful to protect corrosion at box girder upper flange corroded by remaning rain water with calcium chloride.