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Page : 300 - 313
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- PEMFC 금속 분리판용 316L 스테인리스강의 전기화학적 특성 및 손상 거동에 미치는 온도 및 염화물 농도의 영향
- Interest in polymer electrolyte fuel cell is growing to replace fossil fuels. In particular, in order to reduce the cost and volume of the fuel cell, research on a metallic bipolar plate is being actively conducted. In this research, investigated the effects of temperature and chloride concentration on the electrochemical characteristics and damage behavior of 316L stainless steel in an accelerated solution simulating the cathodic operating condition of PEMFC(Polymer electrolyte membrane fuel cell). As a result of the experiments, the corrosion current density, damage size, and surface roughness increased as the temperature and chloride concentration increased. In particular, the temperature had a significant effect on the stability of the
oxide film of 316L stainless steel. In addition, it was described that the growth of the pit was affected by the chloride concentration rather than the temperature. As a result of calculating the corrosion tendency to compare the pitting corrosion rate and the uniform corrosion rate, the uniform corrosion tendency became larger as the temperature increased. And the effects of chloride concentration on corrosion tendency was different according to temperature. - KEYWORDs : PEMFC, Metallic bipolar plate, 316L stainless steel
- AUTHORs : 신동호 · 김성종†
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Page : 314 - 324
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- UNS S31603에 대하여 완전요인설계를 이용한 전해연마조건에 따른 표면 거칠기의 유효인자 산출
- The objective of this investigation was to indentify major factors affecting surface roughness among various parameters of electropolishing process using the design of an experiment method (full factorial design) for UNS S31603. Factors selected included electrolyte composition ratio, applied current density, and electrolytic polishing time. They were compared through analysis of variance (ANOVA). Results of ANOVA revealed that all parameters could affect surface roughness, with the influence of electrolyte composition ratio being the highest. As a result of surface analysis after electropolishing, the specimen with the deepest surface damage was about 35 times greater than the condition with the smallest surface damage. The largest value of surface roughness after electropolishing was higher than that of mechanical polishing due to excessive processing. On the other hand, the smallest value of surface roughness after electropolishing was 0.159 μm, which was improved by more than 80% compared to the previous mechanical polishing. Taken all results together, it is the most appropriate to perform electrolytic polishing with a sulfuric acid and phosphoric acid ratio of 3:7, an applied current density of 300 mA/cm2, and anelectrolytic polishing time of 5 minutes.
- KEYWORDs : Electropolishing, Mechanical polishing, Surface roughness, UNS S31603, Full factorial design
- AUTHORs : 황현규 · 김성종†
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Page : 325 - 0
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- Erratum to: Corrosion Inhibition Studies on Low Carbon Steel in Hydrochloric Acid Medium Using o-Vanillin-Glutamine Schiff Base
- The original version of the article was published in CORROSION SCIENCE AND TECHNOLOGY, Vol. 21, No. 1(2022), pp. 32~40. Unfortunately, the original version
of this article contains a mistake in the author section & affiliation section.
Before correction
G. Rexin Thusnavis†, T. V.Archana, P. Palanisamy
Department of Chemistry, Pioneer Kumaraswamy College, Nagercoil, Tamil Nadu, India
After correction
G. Rexin Thusnavis1,†, T. V. Archana2, P. Palanisamy3
1Assistant Professor, 2Research Scholar (17213152032010),
3Assistant Professor
Department of Chemistry, Pioneer Kumaraswamy College, Nagercoil-629003, Tamilnadu, India
Affiliated to Manonmaniam Sundaranar University, Abishekapatti, Tirunelveli-627012, Tamilnadu, India - KEYWORDs : -
- AUTHORs : G. Rexin Thusnavis†, T. V.Archana, P. Palanisamy
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Page : 327 - 339
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- Effect of Water Impingement Conditions on the Degradation of Epoxy Coatings in Tap Water
- The water-jet technique started by Bridgman can cut metal and alloys without harmful gas and fume. However, while this technique is convenient to cut metals and alloys, in the case of coated pipe, water jet induces the degradation of coatings on the pipes, and may facilitate structural failure, leakage, and loss of products. While there are many reports on the effect of water jet on cut metals and the damage of metallic materials, research on the effect of water impingement on the epoxy coatings has been little studied. In this work, we therefore control the velocity of water jet, distance between nozzle and specimen, and water temperature, and discuss the effect of water impingement on the epoxy coatings. Increasing water velocity and water temperature and reducing nozzle distance increased the degradation rates of three epoxy coatings were increased. Among three test parameters ? water velocity, nozzle distance and water temperature,
water temperature was relatively effective to increase the degradation rate of epoxy coatings. - KEYWORDs : Epoxy coating, Water impingement, Velocity, Nozzle distance, Temperature
- AUTHORs : D. H. Kim, Y. R. Yoo, and Y. S. Kim†
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Page : 340 - 347
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- MMO(Ti/Ru) 코팅된 타이타늄의 고분자 전해질 연료전지 양극환경에서의 전기화학적 거동
- In this research, mixed metal oxide (TiO2, RuO2) coating was applied to grade 1 titanium as a bipolar plate for polymer electrolyte membrane fuel cell (PEMFC). Electrochemical experiments were carried out in an aqueous solution of pH 3 (H2SO4 + 0.1 ppm HF, 80 oC) determined by DoE. The air was bubbled to simulate a cathode environment. Potentiodynamic polarization test revealed that corrosion current densities of the titanium substrate and MMO-coated specimen were 0.180 μA/cm2 and 4.381 μA/cm2, respectively. There was no active peak. After potentiostatic experiment, current densities of the titanium substrate and the MMO-coated specimen were 0.19 μA/cm2 and 1.05 μA/cm2, respectively. As a result of observing the surface before and after the potentiostatic experiment, cracked dried clay structures were observed without corrosion damage. Both the titanium substrate and the MMO-coated specimen could not satisfy the interfacial contact resistance suggested by the DoE. Thus, further research is needed before they could be applied as bipolar plates.
- KEYWORDs : PEMFC, Bipolar plate, Mixed metal oxide, Ruthenium, Titanium
- AUTHORs : 허호성 · 김성종†
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Page : 348 - 359
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- 전기자동차 배터리 하우징용 6061-T6 알루미늄합금의 전식 특성에 미치는 염화물농도 및 인가전류밀도의 영향
- 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.
- KEYWORDs : Electric vehicle battery housing, 6061-T6 Al alloy, Stray current corrosion,
- AUTHORs : 신동호 · 김성종†
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Page : 360 - 371
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- 다구찌 기법을 활용한 통계적·표면 분석에 따른 오스테나이트 스테인리스강의 전해연마조건 최적화 연구
- Electropolishing has various parameters because an electrochemical reaction is applied. Accordingly, experiments to determine factors and levels of electropolishing conditions are in progress for various materials. The purpose of this investigation was to optimize conditions for electropolishing using the taguchi method for UNS S31603. Factors such as electrolyte composition ratio, electrolyte temperature, and electropolishing process time were selected. Electropolishing was optimized using analysis of variance (ANOVA), signal-to-noise ratio (the smaller the better characteristics), and surface analysis. Results of ANOVA revealed that only the electrolyte composition ratio among factors was effective for surface roughness. As a result of statistical analysis of the signal-to-noise ratio, the highest signal-to-noise ratio was calculated under electropolishing conditions with sulfuric acid and phosphoric acid ratio of 4:6, an electrolyte temperature of 75 oC, and electropolishing process time of 7 minutes. In addition, the surface roughness after electropolishing under the above conditions was 0.121 μm, which was improved by more than 88% compared to mechanical polishing.
- KEYWORDs : Electropolishing, Surface roughness, UNS S31603, Taguchi method, SN ratio
- AUTHORs : 황현규 · 김성종†
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Page : 372 - 380
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- 토양 매설 배관의 음극방식과 환경인자 간의 상관관계
- The external corrosion control of buried pipes can be achieved by a combination of coatings and cathodic protection to maximize effectiveness. One of the factors affecting cathodic protection is the environmental soil conditions. Because soil is a kind of electrolyte, the environmental conditions of soil may be changed by the atmospheric environment. Therefore, in this study, changes in environmental soil factors by atmospheric environmental factors were monitored. In cathodic protection, on-potential and off-potential were measured from December 2021 to July 2022. The effects of external environmental factors and soil environmental factors on cathodic protection were analyzed. Changes in outdoor temperature affected soil temperature, and soil conductivity had a proportional relationship with soil humidity, but outdoor humidity and precipitation did not significantly affect humidity and conductivity of the soil. In contrast, in cathodic protection, the on-potential was affected by temperature, humidity, the conductivity of the soil, and the anode used, but the off-potential was little affected by these factors.
- KEYWORDs : Buried pipe, Cathodic Protection, Temperature, Humidity, Conductivity
- AUTHORs : 최승헌 · 원석연 · 유영란 · 김영식†
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Page : 381 - 389
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- Anthocyanins Extracted from Grapes as Green Corrosion Inhibitors for Tin Metal in Citric Acid Solution
- Cyclic Voltammetry and weight loss measurements were used to investigate corrosion prevention of tin in a 0.5M citric acid solution containing Anthocyanins extracted from grapes at various concentrations and temperatures. Results showed that the investigated chemicals, Anthocyanins extracted from grapes, performed well as tin corrosion inhibitors in 0.5M citric acid. Increasing the concentration of Anthocyanins increased their corrosion inhibition efficiencies. When the temperature dropped, their inhibition efficiencies, increased indicating that higher temperature tin dissolution predominated the adsorption of Anthocyanins at the surface of tin metal. When inhibitor concentrations were increased, their inhibition efficiencies were also increased. These results revealed that corrosion of tin metal was inhibited by a mixed type of adsorption on the metal surface. The adsorption isotherm of Langmuir governed the adsorption of Anthocyanins. Thermodynamic parameters such as the enthalpy of adsorption, the entropy of adsorption, and Gibbs free energy and kinetic parameters such as activation energy, enthalpy of activation, and entropy of activation were computed and discussed in this study.
- KEYWORDs : Corrosion inhibitors, Tin metal, Cyclic Voltammetry, Weight loss, Adsorption
- AUTHORs : Mervate Mohamed Mohamed†, Raiedhah Alsaiari, Fatima A. Al-Qadri, Iman Mohammad Shedaiwa, Mabkhoot Alsaiari, Esraa Mohamed Musa, Faeza Alkorbi1 and Ali S. Alkorbi
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Page : 390 - 411
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- A State-of-the-Art Review of Graphene-Based Corrosion Resistant Coatings for Metal Protection
- 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.
- KEYWORDs : Graphene, Corrosion resistance, Water base coating, Metal protection, Corrosive media
- AUTHORs : Ganesh S. Zade and Kiran D. Patil†
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