• Magazine of the Korea Concrete Institute
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• v.6 no.6
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• pp.173-179
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• 1994

Epoxy coated bars protecting reinforcing bars from corrosion and enhancing durability of reinforced concrete structures are tested to evaluate corrosion protection properties. Tests are performed based on the relevant sta.ndards of KS and ASTM, such as chenical resistance, salt water spray, salt crock test and chloride ermeability test. with the main varlable of the coating thlckness. Test results show good chemical protection property and chloride permeability. The results of the salt water spray and the salt crock test show that epoxy coating well protects the reinforcing bars from corrosion, cornparing to the biack bars without epoxy coatmg. However, several spots on the coated bars are rusted at the pinholes or un the bars with coating thickness less thar $200{\mu}M$. Special cautions are required i n the process of blast cleanmg when applying the usion-bonded epoxy coating.

• Corrosion Science and Technology
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• v.16 no.5
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• pp.235-240
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• 2017

Regional cathodic protection has significant impact on pipeline integrity management. After risk analyses of a newly built gas distribution station constructed in an area with large dwelling density, risk score was high because of potential threat caused by galvanic corrosion. Except reinforced steel in concrete, there are four kinds of metal buried under earth: carbon steel, galvanized flat steel, zinc rod and graphite module. To protect buried pipeline from external corrosion, design and construction of regional cathodic protection was proposed. Current density was measured with potential using potential dynamic test and boundary element method (BEM) was used to calculate current requirement and optimize best anode placement during design. From our calculation on the potential, optimized conditions for this area were that an applied current was 3A and anode was placed at 40 meters deep from the soil surface. It results in potential range between $-1.128V_{CSE}$ and $-0.863V_{CSE}$, meeting the $-0.85V_{CSE}$ criterion and the $-1.2V_{CSE}$ criterion that no potential was more negative than $-1.2V_{CSE}$ to cause hydrogen evolution at defects in coating of the pipeline.

• Corrosion Science and Technology
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• v.8 no.4
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• pp.133-138
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• 2009

For the corrosion protection of the natural gas transmission pipelines, two methods are used, cathodic protection and coating technique. In the case of cathodic protection, defects are embrittled by occurring hydrogen at the crack tip or material surface. It is however very important to evaluate whether cracks in the embrittled area can grow or not, especially in weld metal. In this work, on the basis of elastic plastic fracture mechanics, we performed the CTOD testing with various test conditions, such as testing rate and potential. The CTOD of the base metal and the weld metal showed a strong dependence of the test conditions. The CTOD decreased with decreasing testing rate and with increasing cathodic potential. The morphology of the fracture surface showed the quasi-cleavage at low testing rate and cathodic overprotection. The low CTOD was caused by hydrogen embrittlement at crack tip.

• Corrosion Science and Technology
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• v.11 no.6
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• pp.242-246
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• 2012

This measurement represents the effectiveness of sacrificial anode cathodic protection (SACP) system in a coastal bridge structure. To verify the cathodic protection (CP) effect, the monitoring sensor (DMS-100) that could measure potential, corrosion rate, current, concrete resistivity, and temperature was embedded. The measurement conducted for three years after CP system was installed. Specifically, due to the fact that fresh water and sea water was repeated in the bridge structure, this bridge structure presented special CP behavior. Measurement factors were CP potential, CP current, concrete resistivity, and depolarization potential. In addition, visual inspection was also carried out. As a result of current and depolarization measurement, CP system was well activated in most piers.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.429-432
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• 2008

Cathodic Protection Method was introduced as a corrosion protection method of metals under the ground or sea. Since 1970, it was applied to corrosion protection method of reinforced concrete structures. After 1990, this method has been used around the world, and its usability was proved. But this method has some problems on the aspect of construction and economy. In order to solve these problems, Cathodic Protection Method by using high durable metal spray was developed. First, the specimen was covered with anodic materials (Zn, Al) by using metal spray. And a performance of corrosion protection was confirmed by measuring corrosion current of specimen. Through the result of experiment, it is possible to know that Cathodic Protection Method by using high metal spray is good to protect to corrosion on reinforced concrete structures.

• Proceedings of the KIEE Conference
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• 2002.11d
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• pp.249-252
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• 2002

Recently, the advanced countries are using the corrosion monitoring system in a chemical plant and an oil tank in order to protect the corrosion because it leads to a big accident, pollution of soil. and lose of money Generally. the owners of the facilities adopt CP(Cathodic Protection) systems to protect the corrosion also. However, a CP system for oil tank was not considered in Korea Moreover they didn't adopted a corrosion monitoring system. In this paper, we have been developed not only the remote automatic corrosion monitoring but also the remote corrosion control system using the high efficiency CP rectifier. This results should be used to operate the CP system effectively and economically. And also it will be possible to extend the expectation life of the Oil tanks.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2005.06a
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• pp.395-400
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• 2005

The ship hull part is always exposed to severe corrosive environments. Therefore, it should be protected in appropriate ways to reduce corrosion problems. So there are two effective methods in order to protect the corrosion of ship hull. One is the paint coating as a barrier between steel and electrolyte (seawater) and the other is the cathodic protection(CP) supplying protection current. In the conventional design process of the cathodic protection system the required current densities of protected materials have been used. However, the anode position of field or laboratory experiment for obtaining the required current density for CP is significantly different from anode position for real structures. Therefore, the recent CP design must consider the optimum anode position for potential distribution equally over the ship hull. The CP design companies in the advanced countries can obtain the potential distribution results on the cathodic materials by using the computer analysis module. This study would show how to approach the potential analysis in the field of corrosion engineering. The computer program can predict the under protection area on the structure when the boundary condition and analysis procedure are reasonable. In this analysis the polarization curve is converted to the boundary condition in material data.

• Resources Recycling
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• v.18 no.4
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• pp.44-51
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• 2009

In order to verify the effect of Surface Coating Anode and Solar Battery anode system, accelerated tests in the presence or absence of some chloride content and cracks were carried out. The potential-decay, protection potential and corrosion current density of reinforcing steel in concrete specimen were measured to evaluate the effectiveness of the system. From the test results, the application of the system led to the satisfaction on NACE's criterion in all mixtures of concrete. Additionally it was found that protection potential and corrosion current density were satisfied due to the application of Surface Coating Anode and Solar Battery anode system.

• Corrosion Science and Technology
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• v.21 no.5
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• pp.390-411
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• 2022

Any design engineer or coating formulator's primary objective is to protect metals. Large investments in terms of money, time, labour, and other resources are necessary for constructing large-scale machinery and structures. In terms of economy, the structure's lifespan should be as long as feasible to create revenue. It is becoming essential to protect metal substrates from corrosion to prolong the lifespan of such huge structures. One of the most exciting, durable, useful, and effective methods to protect metals from corrosion is the application of corrosion-resistant coating. Graphene is a novel material with a wide range of applications because of its extraordinary features. The use of graphene in coating creates an obstacle and complicates the path for corrosive medium to reach the metal. As the path to the metal elongates, the corrosion medium takes longer to reach the metal. Thus, metal corrosion can be avoided. In this paper, the importance of graphene in coating formulation is discussed, including chemical modifications of graphene, the effect of graphene concentration on corrosion inhibition, and the contact angle of coating. This review also highlights the significance of water-based corrosion-resistant coating for preventing environmental damage.

• Corrosion Science and Technology
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• v.9 no.1
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• pp.48-55
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• 2010

The many vessels are built with FRP(Fiber-Reinforced Plastic) material for small boats and medium vessels. However, FRP is impossible to be used for recyclable material owing to environmental problems and causes large proportion of collision accidents because radar reflection wave is so weak that large vessels could not detect FRP ships during the sailing. Hence, Al alloy comes into the spotlight to solve these kinds of problems as a new-material for next generation instead of FRP. Al alloy ships are getting widely introduced for fish and leisure boats to save fuel consumption due to lightweight. In this study, it was selected 6061-T6 Al alloy which are mainly used for Al-ships and carried out various electrochemical experiment such as potential, anodic/cathodic polarization, Tafel analysis, potentiostatic experiment and surface morphologies observation after potentiostatic experiment for 1200 sec by using the SEM equipment to evaluate optimum corrosion protection potential in sea water. It is concluded that the optimum corrosion protection potential range is -1.4 V ~ -0.7 V(Ag/AgCl) for 6061-T6 Al alloy, in the case of application of ICCP(Impressed current cathodic protection), which was shown the lowest current density at the electrochemical experiment and good specimen surface morphologies after potentiostatic experiment for Al-Mg-Si(6061-T6) Al alloy in seawater environment.