• 한국구조물진단유지관리공학회 논문집
• /
• 제17권4호
• /
• pp.66-74
• /
• 2013

본 연구에서는 부동태피막형 무기계 방청제와 흡착형 유기계 방청제를 대상으로, 시멘트세공용액을 모사한 포화 수산화칼슘 수용액내에서 염화물이온 농도와 방청성분 몰비를 변수로 하여 Potentiostat을 사용하여 부식전위, 부식속도, 분극저항을 측정하여 방식성능을 평가하였다. 그 결과, 무기계 방청제는 방청몰비 약 1.2 이상에서 방식성능을 확보하는 것으로 나타났고, 유기계 방청제는 방청몰비 약 0.3 이상에서 방식성능을 확보하는 것으로 나타났다. 또한, 부식속도와 분극저항, 부식속도와 부식전위의 관계는 선형 반비례 경향을 나타냈고, 분극저항과 부식전위는 선형 비례하는 것을 알 수 있었으며, 부식전위, 부식속도, 분극저항과의 상관관계는 유기계와 무기계 방청제에서 큰 차이가 없는 것으로 나타났다.

• 한국표면공학회:학술대회논문집
• /
• 한국표면공학회 2009년도 춘계학술대회 논문집
• /
• pp.227-227
• /
• 2009

Zn-Mg 합금박막 강판의 열처리 온도에 따른 내식특성 변화를 연구하기 위하여 XRD 분석 및 전기화학적 실험을 실시하였다. 실험 결과에 의하면, 부식전위(Ecorr)상승을 통해 합금화 정도를 간접적으로 측정할 수 있었음은 물론 부식전류밀도(Ecorr) 측정을 통해 내식성을 비교 평가 할 수 있었다.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2011년도 추계 학술논문 발표대회
• /
• pp.221-223
• /
• 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.

• 동력기계공학회지
• /
• 제18권6호
• /
• pp.40-44
• /
• 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.

• 동력기계공학회지
• /
• 제18권4호
• /
• pp.72-77
• /
• 2014

The aim of this study to investigate polarization characteristics of WC-based alloy coatings fabricated by high velocity oxygen fuel(HVOF) process. The coatings were fabricated by HVOF process with WC-CrC-Ni, WC-Co-Cr, WC-Co composite powders. Corrosion tests were carried out using potentiostat/galvanostat at solution with pH 2 and pH 6. Corrosion potential(Ecorr) and corrosion current density(Icorr) could be analyzed from polarization curve. WC-Co-Cr coating showed more incorrodible characteristics than other coatings at solution pH 2. WC-CrC-Ni coating was more favorable anti-corrosion characteristics than other coatings at solution with pH 6.

• Journal of Advanced Marine Engineering and Technology
• /
• 제22권5호
• /
• pp.702-711
• /
• 1998

The characteristics of corrosion resistance for the surface of medium high carbon steels and low alloy steels utilizing as manufacturing the machinery structures and machining tools and treating by plasma/ion nitriding process have been studied in terms of electrochemical polarization behav-iors including corrosion potential(Ecorr) anodic polarization trends and polarization resistance(Rp) The seven base materials showed a clear passivation behavior for the polarization tests in the ASTM standard solution 1N ${H_2){SO_4}$ Although the treated surface by plasma nitriding for the seven test materials showed a significant increase in hardness the treatment gave a detri-mental effect in corrosion resistance. The various characteristics including corrosion potential polarization curves microstructures corrosion current polarization resistance among non-treat-ed nitriding and/or soft-nitriding treated specimens have been investigated and some of the mechanisms discussed.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2021년도 봄 학술논문 발표대회
• /
• pp.221-222
• /
• 2021

Bacterial self-healing concrete is known to improve the durability of concrete by preventing the propagation of microcracks. In the literature, bacteria prevent the corrosion of rebar by inhibiting water transfer through crack, but also can promote the corrosion by acting as an ion acceptor in the rust generation mechanism. Therefore in this study, the electrochemical analysis of bio-filmed rebar was conducted to explore the effects of the self-healing bacteria on the bare rebar without cement composite. As a result of the experiment contradicting trends for Ecorr and Icorr occurred and additional experiment will be conducted in various environments to collect data on the mechanism of corrosion of rebar by bacteria.

• 동력기계공학회지
• /
• 제17권4호
• /
• pp.79-85
• /
• 2013

This study aims at investigating the effect of a fusing treatments on anti-corrosion characteristics of Ni-based self-flux alloy coating. Ni-based coatings were fabricated by flame spray process on steel substrates, and fusing treatments were performed using a vacuum furnace at $800^{\circ}C$ $900^{\circ}C$, $1000^{\circ}C$ and $1100^{\circ}C$. After fusing treatments, corrosion tests were carried out using potentiostat/galvanostat at solution with pH 2 and pH 6. Corrosion potential(Ecorr) and corrosion current density(Icorr) could be analyzed from polarization curve. Fusing-treated coating at $1100^{\circ}C$ showed more favorable anti-corrosion characteristics than as-sprayed coating. Anticorrosive effect of fusing-treated coating at solution with pH 2 was relatively greater than at solution with pH 6. Fusing-treated coating at $1100^{\circ}C$ showed the most excellent anti-corrosion characteristics.

• 한국신뢰성학회지:신뢰성응용연구
• /
• 제17권2호
• /
• pp.122-128
• /
• 2017

Purpose: To investigate the corrosion inhibition effect of the natural spearmint oil extracted from Mentha Spicata plants on 304 stainless steel in different concentrations of hydrochloric acid. Method: The anti-corrosive effect has been investigated in 0.5m, 1m and 2m HCl using weight loss test and electrochemical polarization method as a function of inhibitor concentration and immersion time in strong chloride environment. The surface morphology was analysed by scanning electron microscopy (SEM). Results: The corrosion rate of steel decreased and inhibition efficiency increased with the increase in inhibitor concentration. Microscopic evaluation revealed significant corrosion in the specimens immersed in uninhibited conditions. Potentiodynamic polarization test results showed an increase in corrosion potential (Ecorr) and decrease in corrosion current (icorr) value with increasing concentration of inhibitor. Conclusions: Immersion of steel in higher concentration of inhibitor resulted in greater surface coverage value and hence lesser number of surface corrosion sites/pores were formed; thus lowering the corrosion rate.

• 한국해양공학회지
• /
• 제19권6호통권67호
• /
• pp.72-77
• /
• 2005

The materials used in a ship screw propeller are commonly made with brass. The seawater corrosion and seawater cavitation of the screw propeller reduces the propulsive performance of the ship. In screw manufacturing, the corrosion rust of the screw propeller is removed through a hand grinding method. The grinding process produces dust of the heavy metals from the brass. The dust creates a poor working environment that is harmful to the health of the workers. An automatic corrosionrust removing apparatus, using a blasting method, was developed for the improvement of screw polishing conditions and its working environment. The performance of this apparatus was investigated by surface roughness, weight loss rate, hardness, electrochemical corrosion resistance, and cavitation erosion, after removing of the corrosion rust under various blasting conditions. Two medias of alumina and emery were used in this experiment. The surface roughness and hardness of the screw were improved by this apparatus. The electrochemical corrosion potential (Ecorr) and current density (Icorr) were measured by the dynamic polarization method, using a potentiostat,under the conditions of surface polishing with grinding, blasting, wire brushing, and fine sand papering. The test results prove that the new corrosion rust-removing apparatus improves the surface performance of a screw propeller.