• Corrosion Science and Technology
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• v.10 no.6
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• pp.205-211
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• 2011

The severe corrosion environment makes the steel product lifecycle short while Cu-alloys with anti-corrosion characteristic used in sea water are too expensive. This study shows that the Cu-alloy(Cu-37.25% Zn-0.67%Al) used in sea water environment can be superseded by SS400 with various coating process, evaluating electrochemical characteristics. Three coating processes were applied to SS400 such as PTFE + Zn coaing, Zn + PTFE coating and only Zn electrogalvanizing coaing. Various electrochemical experiments such as open circuit potential measurments, potentiodynamic polarization tests and analyses of Tafel constants. Mechanical properties were also measured by tensile test and hardness tests. As a result, Zn + PTFE coating for SS400 steel presented the excellent anti-corrosion characteristic in sea water.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.241-246
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• 2003

In order to develop a method of corrosion fatigue design and estimate reliability of TMCP steel using as the material of heavy industries and plants, its corrosion susceptibilities, corrosion fatigue strength, and determination of fatigue design criterion considering corrosion degradation were investigated. From the results, the corrosion characteristic of TMCP steel is very susceptible in 3.5wt.% NaCl solution. Its susceptibility was linearly increased with the solution temperature increase. The corrosion fatigue strength in $25${\circ}$, 3.5wt.% NaCl solution is very lower than that of in air. And also, it was decreased with the frequency decrease in the same environment. It is expected that the developed corrosion fatigue design method for TMCP steel is useful. However, it is necessary to verify its reliability for actual application.

• Journal of the Korea institute for structural maintenance and inspection
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• v.5 no.1
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• pp.188-194
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• 2001

A reinforced concrete structure is complex structure that works as one body with bonding role of steel bar and concrete. The bonding action between steel bar and concrete makes possible the compound structure. The transmission of mutual strength of the steel bar with concrete in structure is determined by the bonding characteristic of steel bar and concrete surface. But the efficiency of bonding characteristic of steel bar is Questionable by the corrosion cause by the delay construction term, the wrong management, etc. So this study investigate bonding characteristic of reinforced concrete using pull-out test method which steel bar removed rust and the principal variables of this study are concrete compression strength and the degree of corrosion. The result showed that bonding strength tend to increase when removed rust of steel bar whereas it tend to decrease when not removed rust.

• Proceedings of the KIEE Conference
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• 2006.07a
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• pp.309-310
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• 2006

The considerations for remaining life of ACSR (Aluminum Stranded Conductors Steel Reinforced) in transmission lines has become gradually important to hold reliability and stability of power supply. The remaining life of ACSR exposed to the atmosphere for a long period may rely on deterioration caused by environmental indices such as atmospheric corrosion, galvanic corrosion, crevice corrosion and fatigue corrosion. This paper deals with material characteristic of ACSR due to eccentricity at sleeve point. Test samples are ACSR 240[$mm^2$] conductors, which are real transmission lines. As a result, it is obvious that ACSR due to eccentricity may lead to mechanical deterioration.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.220-225
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• 2003

In order to develop a method of corrosion fatigue design and estimate reliability of TMCP steel using as the material of heavy industries and plants, its corrosion susceptibilities and corrosion fatigue life considering corrosion degradation were investigated. From the results, the corrosion characteristic of TMCP steel is very susceptible in 3.5wt.% NaCl solution. Its susceptibility was linearly increased with the solution temperature increase. The potential difference due to the crack growth behavior in $25^{\circ}C$, 3.5wt.% NaCl solution is very susceptible. And it was found that stress amplitude has a linear relationship with the critical potential. Therefore, it is expected that the corrosion fatigue life of TMCP steel can be nondestructively predicted using the DCPD method.

• Nuclear Engineering and Technology
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• v.56 no.9
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• pp.3616-3625
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• 2024

With the aim to determine the potential corrosion effects of solid boric acid (BA) on light water reactors or other BA-involved equipment, the corrosion behaviors of solid BA on 304 stainless steel (SS) at different temperatures were investigated. Upon comparing the corrosion behaviors of solid BA at different temperatures, significant localized corrosion was observed on 304 SS surfaces at 150 ℃ following 90-day. This localized corrosion exhibited a characteristic pattern of scattered corrosion craters including B-containing Cr-rich oxides. These oxides were found to originate within micro-cracks, gradually evolving into scar-like protrusions within the craters. The proposed corrosion mechanisms entail the interactions between solid BA and chromium oxides/hydroxides, leading to the formation of B-containing Cr-rich oxides. Our findings offer insights into potential corrosion incidents and protective strategies for industries dealing with solid BA.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2011.11a
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• pp.221-223
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• 2011

In this study, in order to comprehend performance of corrosion inhibitor, the experiment study was conducted about corrosion characteristic of 3 steps(0.0, norm 1/2, norm) compared to organic corrosion inhibitor standard use of liquid and molar 3 steps(0.0, 0.3, 0.6%) of Chloride by added amount of inorganic corrosion inhibitor by the corrosion inhibitor types about 2.4kg/㎥, 4.8kg/㎥ based on Chloride ion content 1.2kg/㎥ for service life prediction of concrete structure by using Poteniostat.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.28 no.2
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• pp.216-227
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• 1992

The corrosion rate, behavior of corrosion fatigue and characteristic of cathodic protection for SB41 were investigated by corrosion and corrosion control tests in seawater at laboratory and coast. The main result obtained are as the following; 1) The corrosion rate of base metal (BM) is about 28-37 mg/dm super(2) day in seawater of coast. 2) The correlation between the stress intensity factor range $\Delta$K and crack propagation rate da/dN for weldment follows paris' rule in seawater : da/dN=C($\Delta$K) super(m) where m is the slope of the correlation, and is 2.02 for BM and 1.75 for heat affected zone (HAZ) respectively. 3) The corrosion sensitivity of HAZ is more sensitive than that of BM under the low region of $\Delta$K. 4) With increase of bared surace area of cathode, cathodic protection potential is increased sharply.

• Journal of the Korean institute of surface engineering
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• v.32 no.3
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• pp.472-483
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• 1999

Hard coatings playa continuously increasing role in the field of tribology as well as for decorative applications. In both areas they are often also exposed to corrosive media. While especially hard nitride coatings show a high corrosion resistance for themselves, hard $coating_strate systems may suffer from a severe corrosion attack due to the defects in the coating structure (pores, pinholes) resulting from the PVD-typical film morphology. While a huge number of investigations cover the tribological properties, only limited studies deal with the corrosion behavjour of coating substrate systems and attempts are made to improve their corrosion resistance. The present paper shortly describes the corrosion mechanisms and repots characteristic examples of the system behaviour. Special emphasis is laid on recent investigations to improve the corrosion resistance by alloying, interlayers or multilayered coating structures.es.

• Corrosion Science and Technology
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• v.19 no.5
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• pp.259-264
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• 2020

Many studies have been conducted to improve the corrosion resistance and durability of various aluminum alloys through the anodizing technique. It is already used as a unique technique for enhancing the properties of aluminum alloys in various industries. This paper investigated the electrochemical corrosion and stress corrosion cracking characteristics of anodized aluminum 5083-H321 alloy in natural seawater. The corrosion characteristics were assessed by the electrochemical technique and potentiodynamic polarization test. The stress corrosion cracking characteristic was evaluated with a slow strain rate tensile test under 0.005 mm/min rate, which showed that the hard anodizing film had a thickness of about 16.8 ㎛. Although no significant characteristics of stress corrosion cracking were observed in the slow strain rate test, the anodized specimen presented excellent corrosion resistance. The corrosion current density was measured to be approximately 4.2 times lower than that of the base material, and no surface damage was observed in the anodic polarization test.