• Corrosion Science and Technology
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• 제17권2호
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• pp.54-59
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• 2018

The effect of external DC electric field on atmospheric corrosion behavior of zinc under a thin electrolyte layer (TEL) was investigated by measuring open circuit potential (OCP), cathodic polarization curve, and electrochemical impedance spectroscopy (EIS). Results of OCP vs. time curves indicated that the application of external DC electric field resulted in a negative shift of OCP of zinc. Results of cathodic polarization curves measurement and EIS measurement showed that the reduction current of oxygen increased while charge transfer resistance ($R_{ct}$) decreased under the external DC electric field. Variation of OCP negative shift, reduction current of oxygen, and $R_{ct}$ increase with increasing of external DC electric field strength as well as the effect of external DC electric field on double-layer structure in the electrode/electrolyte interface and ions distribution in thin electrolyte layer were analyzed. All results showed that the external DC electric field could accelerate the corrosion of zinc under a thin electrolyte layer.

• Corrosion Science and Technology
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• 제21권5호
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• pp.348-359
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• 2022

Interest in electric vehicle is on the rise due to global eco-friendly policies. To improve the efficiency of electric vehicles, it is essential to reduce weights of components. Since electric vehicles have various electronic equipment, the research on stray current corrosion is required. In this research, a galvanostatic corrosion experiment was performed on 6061-T6 Al alloy for electric vehicle battery housing using chloride concentration and applied current density as variables in a solution simulating an acid rain environment. As a result of the experiment, when chloride concentration and applied current density were increased, corrosion damage became larger. In particular, pitting damage was dominant at an applied current density of 0.1 mA/cm². Pitting damage over the entire surface was found at a current density of 1.0 mA/cm². In conclusion, chloride concentration had a relatively large effect on localized corrosion. The applied current density had a great effect on uniform corrosion. However, in the case of applied current density, localized corrosion was also greatly affected by interaction with chloride.

• 한국군사과학기술학회지
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• 제11권2호
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• pp.43-52
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• 2008

The galvanic corrosion of a vessel, or systems fitted to minimize the ship's corrosion such as ICCP (Impressed Current Cathodic Protection) system and sacrificial anodes, can lead to significant electrical current flow in the sea. The presence of vessel's current sources associated with corrosion will give rise to detectable electric field surrounding the vessel and can put it at risk from mine threats. For this reason, it is necessary to design corrosion protection systems so that they don't only prevent a hull corrosion but also minimize the electric field signature. In this paper, we describe theoretical backgrounds of underwater electric field signature due to corrosion and corrosion protection system on naval vessels and analysis results of the electric field according to the ship's hull and it's propeller coating damage and ICCP anode displacement.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.876-878
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• 2008

The galvanic corrosion of a vessel, or systems fitted to minimize the ship's corrosion such as ICCP(Impressed Current Cathodic Protection) system and sacrificial anodes, can lead to significant electrical current flow in the sea. The presence of vessel's current sources associated with corrosion will give rise to detectable electric field surrounding the vessel and can put it at risk from mine threats. For this reason, it is necessary to design corrosion protection systems so that they don't only prevent a hull corrosion but also minimize the electric field signature. In this paper, we describe theoretical backgrounds of underwater electric field signature due to corrosion and corrosion protection system on naval vessels and analysis results of the electric field according to ICCP anode arrangement.

• 조명전기설비학회논문지
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• 제24권8호
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• pp.21-26
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• 2010

최근 전력구동 수송수단의 보편화로 그 주변에서 발생하는 누설전류로 인한 지하 금속매설물의 전기부식 문제의 심각성이 대두되고 있다. 본 논문에서는 전식에 대한 이론적인 개념과 구체적인 현상을 확인하고 전력구동 수송시스템에서 전식을 최소화할 수 있는 전기화학적 방안에 대하여 연구하였다.

• Corrosion Science and Technology
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• 제18권4호
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• pp.117-120
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• 2019

Considering the tendency of development of electrification vehicles, development and verification of new evaluation technology is needed because of new technology applications. Recently, as the battery package is set outdoors of an electric vehicle, such vehicles are exposed to corrosive environments. Among major components connected to the battery package, rust prevention of high-voltage cables and connectors is considered the most important issue. For example, if corrosion of high voltage cable connectors occurs, the corrosion durability assessment of using an electric vehicle will be different from general environmental corrosion phenomena. The purpose of this study is to investigate the corrosion mechanism of high voltage cable connectors of an electric vehicle under various driving environments (road surface vibration, corrosion environment, current conduction by stray current, etc.) and develop an optimal rust prevention solution. To improve our parts test method, we have proposed a realistic test method to reproduce actual electric vehicle corrosion issues based on the principle test.

• KEPCO Journal on Electric Power and Energy
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• 제2권4호
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• pp.615-618
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• 2016

Electrochemical noise(EN) has been used to analyze the deterioration of coating films of offshore wind substructures. In this study, prototype sensors using EN have been developed to detect the corrosion rate. To verify the reliability of sensors, experiments were conducted both in the laboratory and offshore using probe and standard samples. New analysis and data processing techniques show that the sensor can provide useful information about the corrosion rate.

• Corrosion Science and Technology
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• 제16권1호
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• pp.8-14
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• 2017

The corrosion behavior of a ferritic/martensitic steel T91 exposed to an aqueous solution containing chloride and sulfate ions is investigated depending on the stimulated all-volatile treatment (AVT) and under oxygenated treatment (OT) conditions. The corrosion of T91 steel under OT condition is severe, while the corrosion under AVT condition is not. The co-existence of chloride and sulfate ions has antagonistic effect on the corrosion of T91 steel in both AVT and OT conditions. Unlike to corrosion resistance in the aqueous solution, OT pretreatment provides T91 steel lower oxidation-resistance than VAT pretreatment. From scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDS) and X-ray diffraction (XRD) analysis, the lower corrosion resistance in the aqueous solution by VAT conditions possibly is due to the formation of pits. In addition, the lower oxidation resistance of T91 steel pretreated by OT conditions is explained as follows: the cracks formed during the immersion under OT conditions accelerated peeling-off rate of the oxide film.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 추계학술대회 논문집
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• pp.988-993
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• 2004

This paper considers corrosion problems in the bolt connection of weathering steel box girder bridge using the external electric type corrosion resistance method which resisted to local corrosion in coated steel surface with contacted air. The weathering steel was created a rust itself in the passive state. but a coated box girder type was easily dew form could be made galvanic cell that accelerated corrosion. so that it was ruled by protection coat with some paint. Therefore, it needed that can be applied the external electric type corrosion resistance method in coated surface. As a result of the test of polarization amount had measured that the weathering steel was higher currents than the general steel by about $5\~10\%$. Therefore. an external electric type corrosion resistance method can be used to protect local corrosion in the coated bolt connection of weathering steel box girders effectively.

• Journal of Electrochemical Science and Technology
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• 제11권4호
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• pp.368-378
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• 2020

In the paper, corrosion behavior of T91 steel in different concentrations of NaHSO₃ solution was studied in combination with scanning electron microscope (SEM) and electrochemical measurements. The results showed that the steel exhibited active anodic dissolution characteristics in the solution, and NaHSO₃ concentration affected both cathodic and anodic behaviors. The steel surface was covered by intact corrosion products in the solutions, but the compactness and mechanical properties of the corrosion products degraded with the increase of NaHSO₃ concentration. In low-concentration NaHSO₃ solution the steel tended to undergo uniform corrosion with slight corrosion pits, but its corrosion mode gradually transited to localized corrosion as the NaHSO₃ concentration increased. The mechanical property degradation of the corrosion products caused by sulfur compounds and the pH decrease of the solution are the important factors to accelerating its corrosion process.