• 제목/요약/키워드: sacrificial anode

검색결과 79건 처리시간 0.031초

희생양극 하에서 알루미늄의 해수 부식 거동 (Corrosion Behavior of Aluminium Coupled to a Sacrificial Anode in Seawater)

  • 김종수;김희산
    • 한국표면공학회지
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    • 제39권1호
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    • pp.25-34
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    • 2006
  • Al-Mg alloy, an open rack vaporizer(ORV) material was reported to be corroded in seawater environments though the ORV material was coupled to thermally sprayed Al-Zn alloy functioning a sacrificial anode. In addition, the corrosion behavior based on the calculated corrosion potential did not match the observed corrosion behavior. Hence, the goal of this study is to get better understanding on Al or Al-Mg alloy coupled to Al-Zn alloy and to provide the calculated corrosion potential representing the corrosion behavior of the ORV material by immersion test, electrochemical tests, and calculation of corrosion and galvanic potential. The corrosion potentials of Al and Al alloys also depended on alloying element as well as surface defects. The corrosion potentials of Al and Al-Mg alloy were changed with time. In the meantime, the corrosion potentials of Al-Zn alloys were not. The corrosion rates of Al-Zn alloys were exponentially increased with zinc contents. The phenomena were explained with the stability of passive film proved by passive current density depending on pH and confirmed by the model proposed by McCafferty. Dissimilar material crevice corrosion (DMCC) test shows that higher content of zinc caused Al-Mg alloy corroded more rapidly, which was due to the fact that higher corrosion rate of Al-Zn makes [$H^+$] and [$Cl^-$] more concentrated within pit solution to corrode Al-Mg alloy. Considering electrochemical reactions within pit as well as bulk in the calculation gives better prediction on the corrosion behavior of Al and Al-Mg alloy as well as the capability of Al-Zn alloy for corrosion protection.

해수 내 아크 아연 용사코팅 층의 전기화학적 특성 (Electrochemical Characteristics of Arc Zn Thermal Spray Coating Layer in Sea Water)

  • 박일초;서광철;이경우;김성종
    • 한국표면공학회지
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    • 제48권6호
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    • pp.343-348
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    • 2015
  • In this paper, arc Zn thermal spray coating was carried out on the SS400 steel, and then various electrochemical characteristics and surface damage behavior of Zn thermal spray coating layer were analyzed. As the results, the potential of Zn thermal spray coating layer presented driving voltage above 300 mV compare to that of SS400 steel. The passivity characteristic in anodic polarization curve was not presented. It was adequate to as sacrificial anode material. In the surface damage after galvanostatic experiments, uniform corrosion tendency of Zn thermal spray coating layer was clearly observed with acceleration of the dissolution reaction. In conclusion, Zn thermal spray coating could be determined to represent the corrosion protection effect by stable sacrificial anodic cathodic protection method in seawater because it had sufficient driving voltage and uniform corrosion damage tendency for the SS400 steel.

FRP 어선 2종 스테인리스강 축의 음극방식을 위한 실용설계 및 적용방안 연구 (A Study on the Practical Cathodic Protection Design for the FRP Fishing Boat and It’s Application Scheme)

  • 강대선;김기준;이명훈;박정대;김태언
    • 선박안전
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    • 통권21호
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    • pp.66-77
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    • 2006
  • Stainless steel has been stably used closed by passivity oxidation films(Cr₂O₃) is made by neutral atmospheric environment. However, passivity oxidaton films of the surface of stainless steel occasionally comes to be destroyed in seawater which is influenced by an environment having galogen ion like Cl‾, then, localization corrosion comes to occur Stainless steel 304 for shaft system material of the small-size FRP fishing boat on seawater environments made an experiment on simulation of sacrifical anode(Al, Zn). Through these experiment and study, following results have been obtained ; According to the field inspection and corrosion simulation, the corrosion on the 2nd class stainless steel shaft(STS304) in FRP fishing boat has been verified to occur by crevice corrosion and galvanic corrosion etc., According to the comparison and analysis of Stainless steel 304 was severely corroded, but, protected shaft specimen was not totallay corroded. This result is assumed to be made by the facts that anodic reaction, Fe → fe²++ 2e¯, has been restricted by the cathodic protection current of sacrificial anode material.

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해상용 원심펌프 임펠러의 침식억제법으로 음극방식 및 재료개발에 관한 기초연구 1 (Fundamental Study on Cathodic Protection and Material Development as Erosion-Control Methods of Oceanic Centrifugal Pump(1))

  • 이진열;임우조
    • Journal of Advanced Marine Engineering and Technology
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    • 제19권2호
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    • pp.56-66
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    • 1995
  • Recently, with theraped advancement in th oceanology such an ocean-going vessel and oceanic structures, there is a need to study the cavitation erosion-corrosion control of pump impeller, the partial element of ocean machinery, for more effective operation. Especially, the cathodic protection (impressed current method & Al-sacrificial anode method) was applied to sea water, and Cu-alloy material mixed Zn & Al was used as a control method of cavitation erosion-corrosion. In this study, used the piezoelectric vibrator with 20KHz, 24.mu.m to cavity generation apparatus, and investigated the weight loss, weight loss rate, electrode potential & current density etc. under this condition. According to test result, thos describes how to indentify an influence of the cathodic protection and Al & Zn addition in material development for the control of cavitation erosion-corrosion, and those will serve as fundamental data on the cavitation erosion-corrosion control of oceanic centrifugal pump.

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해양금속구조물의 전기방식을 위한 고효율 정류기 개발(II) (The Development of the High-efficiency Rectifier on Marine Metallic Structures(II))

  • 하태현;배정효;김대경;이현구;최상봉;정성환
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2000년도 추계학술대회 논문집 학회본부 D
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    • pp.727-728
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    • 2000
  • The Cathodic Protection system which is usually applied to marine metallic structures in domestic is Sacrificial Anode Method. In general. low efficiency rectifiers are using in the field of Cathodic Protection. These rectifiers are not only low efficiency but also manual type which is not able to control remotely. In this paper we describe the high efficiency rectifier used the high speed switching method for optimum corrosion control of marine metallic structures.

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주조법에 의해 제조된 마그네슘 합금에서 칼슘 첨가가 전기화학적 특성에 미치는 영향 (The Effect of Ca Addition on Electrochemical Properties of Mg-alloy by Casting)

  • Kim, Hye-Sung
    • 한국콘텐츠학회논문지
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    • 제2권1호
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    • pp.120-124
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    • 2002
  • 본 연구에서는 주조법으로 제조한 Mg-Ca 합금의 전기 화학적 특성을 알아보고자 하였다. 연구결과에 의하면 전기화학적 특성이 불순물의 화학조성과 매우 밀접한 관계가 있으며, 칼슘 첨가 전ㆍ후 뚜렷한 미세구조 변화가 있음이 관찰되었다. 본 연구로부터 적은 양의 칼슘이 첨가되면 마그네슘 합금의 미세구조적 변화를 통하여 우수한 전기화학적 특성이 얻어질 수 있음이 확인되었다.

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Effects of rotation speed and time in potentiostatic experiment in seawater for 5083-H116 Al alloy

  • Lee, Seung-Jun;Han, Min-Su;Jang, Seok-Ki;Kim, Seong-Jong
    • Journal of Advanced Marine Engineering and Technology
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    • 제38권8호
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    • pp.974-980
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    • 2014
  • Aluminum acts as sacrificial anode and corrosion protection with Al2O3 formation. If the same current on material for Al ships with steel ships supplies, the more hydrogen would be occurred, that result is bring about over-protection. For this reason, the damage by hydrogen embrittlement leads to the serious accident. In this study, we evaluate electrochemical behavior with rotation speed of 5083-H116 Al alloy material for Al ship in seawater. To examine the electrochemical characteristics with rotation speed and its effects on performance, experiments were conducted at four rotation speed. Results of experiments, the corrosion current density and damage were increased by applying the rotation speed compared to static state.

선체 부식에 의한 수중 전기장 신호 특성 모델링 기법 연구 (A Study on the Modelling Method of Underwater Electric Field Signature due to Ship's Corrosion)

  • 정현주;양창섭;전재진
    • 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.

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Al-Mg 코팅의 내식성에 미치는 Mg 함량 및 열처리의 영향 (Effect of Mg content and heat treatment on the corrosion resistance of Al-Mg coating)

  • 강재욱;박준무;윤용섭;이명훈
    • 한국표면공학회:학술대회논문집
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    • 한국표면공학회 2015년도 추계학술대회 논문집
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    • pp.144-144
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    • 2015
  • 본 연구에서는 PVD법 중의 하나인 스퍼터링(sputtering) 기술을 이용하여 향상된 희생양극(sacrificial anode)적 특성을 가지는 고내식 Al-Mg 막을 제작함은 물론 그 제작 조건에 따른 표면의 몰포로지, 성분 분포, 결정구조 등의 변화를 해석하였다. 또한 표면 및 단면에 대한 염수분무 노출시험을 통해 Mg 성분의 첨가에 따른 막의 내식특성을 평가하였다. 이상의 재료특성 분석 및 내식성 평가 결과간 연구-고찰을 통해 제작 조건과 막의 내식성에 대한 종합적인 연관성을 해석하였으며 이를 통해 최적의 Al-Mg 제작에 대한 기초적인 설계 조건을 제시하고자 하였다.

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누설전류에서 희생양극법을 이용한 전식 방지에 대한 연구 (A Study on the Prevention of the Electric Corrosion by Leakage Current using the Life of Sacrificial Anode Method)

  • 유해출;최홍규
    • 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.