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Page : 107 - 119
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- Adsorption Isotherm, Thermodynamic and Electrochemical Studies of Lawsonia Inermis Leaf Extract as a Sustainable Corrosion Inhibitor of Mild Steel in Acid Medium
- Weight loss method, polarization techniques, and electrochemical impedance spectroscopy (EIS) experi- ments were used to evaluate natural corrosion prevention and adsorption capacities of Lawsonia inermis (Henna) leaf extract on mild steel in 1 M HCl medium. Effect of temperature on mild steel corrosion behavior was studied at a temperature range of 303K?33K. The efficiency of Henna leaf extract in inhib- iting corrosion of mild steel increased with increasing concentration but decreased with increasing tem- perature. Activation and free energies for inhibition reactions support a mechanism of physical adsorption. The adsorption of henna extract on mild steel surface was endothermic and spontaneous, consistent with Langmuir adsorption isotherm. Polarization and EIS measurements indicated that henna extract could act as a mixed type inhibitor. Henna leaf extract as a protective coating was examined using Fourier transform infrared spectroscopy and scanning electron microscopy. Maximum inhibition efficiency at 1 M HCl was (66%) obtained when inhibitor concentration was 400 ppm.
- KEYWORDs : Mild steel, Corrosion inhibition, Lawsonia Inermis Leaf extract, Thermodynamic parameters
- AUTHORs : R. Rajkumar†, C. Kavitha, and S. Pringlin
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Page : 120 - 133
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- Effect of TMN on the Corrosion Inhibition of Carbon Steel in 1 M HCl Solution: Experimental and DFT Studies
- This work aimed to elucidate effect of 1-((thiazol-2-ylimino)methyl)-2-naphthol (TMN) on corrosion inhi- bition of carbon steel in 1 M HCl medium. Corrosion inhibition efficiencies were assessed based pm weight loss measurements and computational Density Functional Theory (DFT) studies. TMN, a very strong adsorbate on surface steel, is expected to show high values of inhibition efficiency since it has excellent electronic properties based on DFT analysis. Inhibition efficiency of TMN increased with increasing concentration. The maximum value was 91.2 at 0.5 mM concentration after 5 hours of immer- sion at 303 K. Study of immersion time at 303 K for different concentrations of the inhibitor indicated an increase in inhibition efficiency with time until 10 hours, followed by a slight decrease until 48 hours. After immersion of 5 hours, corrosion inhibition efficiency increased with increasing temperature from 303 K to 333 K. Adsorption behavior of TMN followed Langmuir adsorption isotherm. For this study, DFT calculations supported the data observed experimentally, confirming that TMN could be utilized as an effi- cient corrosion inhibitor with a strong efficacy.
- KEYWORDs : Schiff base, Corrosion inhibitor, Carbon steel, Weight loss measurements, DFT analysis
- AUTHORs : Rasha Khalid Ahmed, Ali H. Kareem, M.A.I. Al-Hamid, F. F. Sayyid, A. M. Mustafa, A.A.H. Kadhum, A. Alamiery†
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Page : 134 - 150
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- Evaluating the Potential of Ataluren as X80 Steel Corrosion Inhibitor in Acid Wash Solution: An Experimental and Computational Intelligence Approach
- Corrosion inhibition performance of Ataluren (ATA) on X80 steel in oilfield acid wash solution was inves- tigated using a combination of experimental and computational techniques. Corrosion rates were quantified using weight loss analysis and electrochemical methods. Surface morphology and protection mechanisms were examined using spectroscopic and microscopic tools. Quantum chemical calculations and molecular dynamics simulations were performed to evaluate solvation, adsorption behavior, and binding affinity of ATA molecules at the steel interface. Experimental results demonstrated significant reductions of corro- sion rates across various ATA concentrations, achieving inhibition efficiencies of 96.2%, 95.6%, and 96.3% as determined by impedance, polarization and weight loss measurements, respectively, while Monte Carlo simulations supported an inhibition efficiency of 76.1%. Analysis of Fukui indices, Mulliken charge distributions and interaction energies in both gas and aqueous phases, along with EDAX data, indicated that corrosion inhibition was primarily driven by spontaneous exothermic chemisorption involving N and O functionalities in ATA interacting with Fe d-orbitals. This adsorption led to formation of a protective ATA monolayer that significantly reduced surface roughness, as confirmed by SEM. These findings estab- lish ATA as a highly effective corrosion inhibitor for X80 steel under investigated conditions.
- KEYWORDs : Adsorption, Corrosion protection, DFT, Interaction energy, Surface characterization
- AUTHORs : Ekemini Ituen†, Victor Mkpenie, Solomon Shaibu, Lin Yuanhua†, Udoinyang Inyang, Shuangqin Sun, Simphiwe Nelana, Michael Klink, Olushola Ayanda†
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Page : 151 - 161
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- Improving Insulating and Wettability Properties of Titanium Alloys via Electrochemical Anodization
- In this study, anodization was applied to Titanium (Grade 4) alloy to form nanostructured oxide films and resulting changes in surface properties were systematically investigated with respect to anodization time. As the duration of anodization increased, the oxidation reaction was intensified, leading to a progressive thickening of the TiO2 layer. Energy Dispersive X-ray Spectroscopy (EDS) analysis confirmed a gradual increase in oxygen content with a corresponding decrease in titanium content. Additionally, enlargement of pores and surface roughness with longer anodization times resulted in reduced contact angles, indicating enhanced hydrophilicity. Electrical resistance measures revealed that thicker oxide layers effectively impeded electron flow, thereby exhibiting superior insulating characteristics than thinner oxide layers. Overall, these results demonstrate that anodization is a promising surface modification technique for a wide range of applications, including energy devices and electronic components. In particular, the TiO2 oxide layer holds significant potential as a high-performance surface material due to its excellent insulat- ing properties and improved wettability.
- KEYWORDs : Titanium Anodizing, Anodizing Time, Surface Roughness, Wettability, Resistance Test
- AUTHORs : Yeji Choi and Chanyoung Jeong†
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Page : 162 - 174
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- Investigating SDS Surfactant as a Corrosion Inhibitor for Carbon Steel in Hydrochloric Acid: Mechanisms and Efficacy
- The corrosion inhibition performance of sodium dodecyl sulfate (SDS) for carbon steel (CS) in 1 M hydro- chloric acid (HCl) environments was rigorously evaluated using potentiodynamic polarization techniques. This study explored efficacies of SDS at various concentrations and temperatures (20, 30, 40, and 50 oC) for inhibiting corrosion of CS. Findings demonstrated a notable anti-corrosion effect of SDS, with the max- imum inhibition efficiency reaching 70% at 20 oC. The adsorption behavior of SDS conformed to the Langmuir adsorption isotherm as indicated by high correlation coefficients. Computed standard adsorption free energy values suggested that both physisorption and chemisorption of SDS occurred on the CS sur- face. Surface analyses, including atomic force microscopy (AFM) and scanning electron microscopy (SEM), revealed the formation of a uniform protective layer, evidenced by smoother AFM images and reduced corrosion damage in SEM micrographs. A computational investigation using the PM3 method offered additional insights into the observed inhibition efficiencies, enhancing comprehension of the mech- anism of action of SDS invovled in inhibiting corrosion of CS.
- KEYWORDs : Corrosion inhibitor, SDS, Carbon steel, Isotherms, Potentiodynamic polarization
- AUTHORs : Duhak Ahmed Alwan and Oraas Adnan Hatem†
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Page : 175 - 183
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- Evaluation of Corrosion Resistance of Aluminium-Silicon Carbide Composites for Thermal Application
- Aluminium-silicon carbide (Al-SiC) has garnered attention recently due to its advantageous features. Effects of uniform corrosion and pitting corrosion susceptibility of Al-SiC composites in HCl solution were investigated using cyclic potentiodynamic polarization for thermal application. Surface morphology of Al-SiC composites was examined by scanning electron microscope (SEM) and energy Dispersive spec- troscopy (EDS). This study was complemented by examining elemental compositions of various compos- ites through surface analysis methods. Results revealed that composites sintered for 2 hours at 550 °C exhibited a decrease in the rate of uniform corrosion and a diminished susceptibility to pitting corrosion when the solution temperature was elevated. Extending the sintering time for composite to 3 hours led to an enhancement in uniform corrosion, while concurrently mitigating the incidence of pitting corrosion. Uniform corrosion of sintered composites showed a significant dependence on sintering time with increas- ing temperature. Sintering time can potentially affect grain size, resulting in a corrosion behavior.
- KEYWORDs : Al-SiC composites, Cyclic polarization, Powder metallurgy, Temperature, Pitting corrosion
- AUTHORs : Baydaa Jaber Nabhan, Lubna Ghalib†, and Manal Hameed Jasem
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Page : 184 - 192
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- Real Time Crossbow Measurement and Control
- The transverse curvature of a strip referred to as ‘crossbow’ has always been a factor present in the coated steel production process. Its existence at the galvanizing pot and consequence on coating control need to be managed. Many attempts have been made to reduce its effect. Using an array of sensors across a strip, strip position (passline) and strip shape can be measured just above air knives. While the passline shift and crossbow are considered separate effects caused by properties of the substrate and pot roll configuration, they are not independent of each other. In the same way, the control of crossbow by adjusting the cor- recting roll affects both the passline and crossbow. The resulting strip position and curvature measurement can be fed into the coating control air knife and correcting roll positioning systems. This paper presents results from a laser strip profile and passline measurement system employed at air knives. The use of mea- surements of strip shape and subsequent development of a crossbow model and control system that can be used to reduce or minimise the crossbow in the steel strip at air knives are also discussed in this paper
- KEYWORDs : Crossbow, Strip shape, Passline, Correcting roll, Curvature
- AUTHORs : Owen Pearcey†, Ivan Marincic, and Joel Tham
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Page : 193 - 201
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- 해수 담수화 시스템의 해수펌프용 316L 스테인리스강의 마찰부식 특성 연구
- In this paper, tribocorrosion characteristics of 316L stainless steel were investigated. Experimental results revealed that stability of chromium oxide film under corrosion conditions led to an increase in potential and a decrease in corrosion current density. However, under tribocorrosion conditions, destruction of the oxide film by friction led to a decrease in potential and an increase in corrosion current density. This was because grain refinement and residual stress concentration on the surface caused by friction affected the electrochemical stability of the oxide film. However, under corrosion conditions after tribocorrosion exper- iments, the potential increased over time while the corrosion current density decreased due to reformation of the oxide film. Nevertheless, it presented a higher corrosion current density than the corrosion condition due to the influence of defects and residual stress caused by friction. Under tribocorrosion conditions, ini- tial lubrication effect resulted in a low friction coefficient. However, after trans-passive potential, the fric- tion coefficient increased significantly due to destruction of the oxide film. As a result, the wear track appeared to be an area where the electrochemical reaction of corrosive ions was concentrated whereas the surrounding area presented a relatively good corrosion protection effect.
- KEYWORDs : 316L stainless steel, Tribocorrosion, Seawater, Electrochemical characteristics, Mechanical characteristics
- AUTHORs : 신동호 · 김성종†
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Page : 203 - 211
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- Investigation into the Corrosion Mechanism of High-Voltage Cables in Eco-Friendly Vehicles
- This study investigates corrosion mechanisms in high-voltage (HV) cable connectors used in eco-friendly vehicles, focusing on galvanic and stray current corrosion under realistic operating conditions. Severe oxi- dation and pitting were observed at the interface between aluminum connectors and copper ground ter- minals, which are coated with tin (Sn). Mechanical fretting and electrical stress accelerated Sn layer breakdown, exposing the aluminum substrate and forming a galvanic couple with copper. A series of com- bined corrosion tests were carried out under vibration, DC bias, moisture ingress, and their simultaneous action. SEM/EDS analyses confirmed significant fretting wear and Al₂O₃ formation, especially when mechanical and electrical loads acted together. Leakage current measurements showed that both AC and DC systems produced current densities within critical stray current corrosion thresholds, particularly during deceleration and braking. These results reveal a synergistic degradation mechanism involving vibra- tion, electrolyte exposure, and electrical bias. To mitigate corrosion, structural enhancements such as vibra- tion-resistant fastening and environmental sealing are proposed. Overall, the findings provide new insight into HV connector failure mechanisms and present practical design recommendations to enhance durabil- ity and reliability in electric mobility applications.
- KEYWORDs : Corrosion, Eco-Friendly vehicle, High-Voltage cable, Corrosion mechanism, Surface characterization
- AUTHORs : Sungho Shin, Seungho Ahn, and Hyuntaeck Lim†
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Page : 203 - 211
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- Investigation into the Corrosion Mechanism of High-Voltage Cables in Eco-Friendly Vehicles
- This study investigates corrosion mechanisms in high-voltage (HV) cable connectors used in eco-friendly vehicles, focusing on galvanic and stray current corrosion under realistic operating conditions. Severe oxi- dation and pitting were observed at the interface between aluminum connectors and copper ground ter- minals, which are coated with tin (Sn). Mechanical fretting and electrical stress accelerated Sn layer breakdown, exposing the aluminum substrate and forming a galvanic couple with copper. A series of com- bined corrosion tests were carried out under vibration, DC bias, moisture ingress, and their simultaneous action. SEM/EDS analyses confirmed significant fretting wear and Al₂O₃ formation, especially when mechanical and electrical loads acted together. Leakage current measurements showed that both AC and DC systems produced current densities within critical stray current corrosion thresholds, particularly during deceleration and braking. These results reveal a synergistic degradation mechanism involving vibra- tion, electrolyte exposure, and electrical bias. To mitigate corrosion, structural enhancements such as vibra- tion-resistant fastening and environmental sealing are proposed. Overall, the findings provide new insight into HV connector failure mechanisms and present practical design recommendations to enhance durabil- ity and reliability in electric mobility applications.
- KEYWORDs : Corrosion, Eco-Friendly vehicle, High-Voltage cable, Corrosion mechanism, Surface characterization
- AUTHORs : Sungho Shin, Seungho Ahn, and Hyuntaeck Lim†
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