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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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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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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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양극산화 방법을 이용한 기능성 알루미늄 3003 합금의 표면 특성 및 부식 거동 연구
Anodizing is an electrochemical surface treatment method conferring corrosion resistance and durability by forming a thick anodization film on the metal surface. Aluminum has a long service life and high thermal conductivity and formability, as well as excellent corrosion resistance. Aluminum 3003 alloy has improved formability, strength, and corrosion resistance due to the addition of a small amount of manganese. However, corrosion occurs in seawater and environments polluted with corrosion-inducing substances, which reduce corrosion resistance. Therefore, it is necessary to artificially form a thick anodized film to improve corrosion resistance. In this study, the anodization treatment time was 4 minutes, and voltages of 10 V, 20 V, 30 V, 40 V, 50 V, 60 V, 70 V, 80 V, 90 V, and 100 V were applied. The thickness and pore size of the oxide film increased according to the applied voltage. A barrier film was formed under voltage conditions from 10 V to 50 V, and a porous film was formed under voltage conditions from 60 V to 100 V. After anodizing, coating was applied. Wettability and corrosion resistance were observed before and after coating according to the surface shape and thickness of the oxide film.
KEYWORDs : Anodization, Aluminum alloy, Hydrophilicity, Hydrophobicity, Corrosion resistance
AUTHORs : 김지수 · 정찬영†

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알루미늄 1050 합금의 양극산화 시간에 따른 산화피막 성장 거동 및 부식 손상 연구
Aluminum 1000 series alloy, a pure aluminum with excellent workability and weldability, is mainly used in the ship field. Aluminum alloy can combine with oxygen in the atmosphere and form a natural oxide film with high corrosion resistance. However, its corrosion resistance and durability are decreased when it is exposed to a harsh environment for a long period of time. For solving this problem, a porous oxide film can be formed on the surface using an anodizing treatment method, a typical surface technique among various methods. In this study, aluminum 1050 alloy was anodized for 2 minutes, 6 minutes, and 10 minutes. The structure and shape of the oxide film were then analyzed to determine the corrosion resistance according to the thickness of the oxide film that changed depending on working condition using 15 wt% NaCl. After it was immersed in NaCl solution for 1, 5, and 10 days, corrosion damage was observed. Results confirmed that the thickness of the oxide film increased as the anodization time became longer. The depth of surface damage due to corrosion became deeper when the film was immersed in the 15 wt% NaCl solution for a longer period of time.
KEYWORDs : Corrosion resistance, Aluminum alloy, Anodization time, Thickness, Porous oxide film
AUTHORs : 최예지 · 정찬영†

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Effect of Cu Addition on the Properties of Duplex Stainless Steels
The effect of addition of Cu on the localized corrosion performance of aged duplex stainless steel in chloride media has yet to be explained in a consistent manner, and there is some controversy in the literature regarding the composition of stainless steel and the experimental conditions (pH, temperature, chloride concentration, etc.) used. In this work, the effect of the addition of Cu on the microstructure, hardness, and corrosion resistance of duplex stainless steel in an acidic chloride or high concentration sulfuric acid solutions was investigated for annealed and aged alloys. The Cu addition of annealed duplex stainless steel strengthened the alloy and reduced the ferrite contents of the alloy, and it also increased the polarization behavior in chloride or sulfuric solutions, except for the case of a high potential in acidic chloride solution. However, the Cu addition of aged duplex stainless steel reduced the formation of harmful phases such as sigma and kai and increased the polarization behavior in acidic chloride or sulfuric solutions up to 0.8 wt% of the Cu content, after which it slightly decreased at 0.8 wt% Cu or more.
KEYWORDs : Duplex stainless steel, Copper, Sigma phase, Hardness, Corrosion
AUTHORs : D. Hwangbo, Y. R. Yoo, S. H. Choi, S. J. Choi, and Y. S. Kim†

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Atmospheric Corrosion Behavior of Weathering Steel Exposed to the Outdoors for 10 Years in Korea
Steel structures exposed to the outdoors experienced several types of corrosion, which may reduce their thickness. Since atmospheric corrosion can induce economic losses, it is important to consider the atmospheric corrosion behavior of a variety of metals and alloys. This work performed outdoor exposure tests for 10 years at 14 areas in Korea and calculated the atmospheric corrosion rate of weathering steel. This paper discussed the atmospheric corrosion behavior of weathering steel based on various corrosion factors. The average corrosion rates in coastal, industrial, urban, and rural areas were found to range from (2.83 to 4.23) μm/y, (2.99 to 4.23) μm/y, (1.72 to 3.14) μm/y, and (1.57 to 2.85) μm/y respectively. It should be noted that the maximum corrosion rate was about 6.0 times greater than the average corrosion rate. Regardless of the exposure sites, the color differences were increased, but the glossiness was reduced and there was no relationship between the corrosion rate and environmental factors and the glossiness.
KEYWORDs : Weathering steel, Atmospheric corrosion, Corrosion rate, Color difference, Glossiness
AUTHORs : Y. R. Yoo, S. H. Choi, and Y. S. Kim†

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Synthesis and Electrochemical Properties of FexNbS2/C Composites as an Anode Material for Li Secondary Batteries
Transition metal sulfide materials have emerged as a new anode material for Li secondary batteries owing to their high capacity and rate capability facilitated by fast Li-ion transport through the layered structure. Among these materials, niobium disulfide (NbS2) has attracted much attention with its high electrical conductivity and high theoretical capacity (683 mAh g–1). In this study, we propose a facile synthesis of Fex-NbS2/C composite via simple ball milling and heat treatment. The starting materials of FeS and Nb were reacted in the first milling step and transformed into an Fe-Nb-S composite. In the second milling step, activated carbon was incorporated and the sulfide was crystallized into FexNbS2 by heat treatment. The prepared materials were characterized by X-ray diffraction, electron spectroscopies, and X-ray photoelectron spectroscopy. The electrochemical test results reveal that the synthesized FexNbS2/C composite electrode demonstrates a high reversible capacity of more than 600 mAh g–1, stable cycling stability, and excellent rate performance for Li-ion battery anodes.
KEYWORDs : Transition metal dichalcogenide, Niobium sulfide, Composite, Li battery, Electrochemical properties
AUTHORs : Yunjung Kim and Jae-Hun Kim†

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Failure Analysis of Stress Reliever in Heat-Transport Pipe of District Heating System
The objective of the present study was to perform failure analysis of double-layered bellow (expansion joint), a core part of stress reliever, used to relieve axial stresses induced by thermal expansion of heattransport pipes in a district heating system. The bellow underwent tensile or compressive stresses due to its structure in terms of position. A leaked position sufferred a fatigue with a tensile component for decades. A cracked bellow contained a higher fraction of martensitic phase because of manufacturing and usage histories, which induced more brittleness on the component. Inclusions in the inner layer of the bellow acted as a site of stress concentration, from which cracks initiated and then propagated along the hoop direction from the inner surface of the inner layer under fatigue loading conditions. As the crack reached critical thickness, the crack propagated
to the outer surface at a higher rate, resulting in leakage of the stress reliever.
KEYWORDs : District heating, Heat-transport pipe, Stress reliever, Crack
AUTHORs : Jeongmin Cho, Hobyung Chae, Heesan Kim, Jung-Gu Kim, Woo Cheol Kim, and Soo Yeol Lee†

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