Publications by authors named "Jung-Gu Kim"

Article Synopsis
  • The study analyzes how Ti-Pt-coated stainless steel bipolar plates behave under corrosion in a polymer electrolyte membrane water electrolysis (PEMWE) environment, using electrochemical tests and surface analysis.
  • Results show that the coated plates have significantly better corrosion resistance (1.68 × 10 A/cm) compared to bare SS316L plates (1.94 × 10 A/cm).
  • However, the coating's effectiveness decreases in the PEMWE environment due to electrolyte entering blistered areas of the coating, caused by oxygen gas pressure, which leads to corrosion of the underlying substrate.
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  • * The research involved electrochemical tests in simulated environments that mimic conditions inside and outside of a pit to analyze how benzotriazole affects pit propagation.
  • * Results indicated that both concentrations of benzotriazole showed low efficiency in preventing corrosion in acidic conditions due to challenges in forming a protective layer and issues with benzotriazole cationization.
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  • This study evaluates the corrosion resistance of Type 316 stainless steel for use in radioactive waste disposal canisters, focusing on conditions similar to groundwater and various concentrations of pH, bisulfide ions (HS), and chloride ions (Cl).
  • The research employs response surface methodology to relate corrosion factors to key outcomes like passive film breakdown potential and protection potential, confirmed through cyclic potentiodynamic polarization tests.
  • Findings reveal that while HS weakens the passive film and impacts pitting corrosion resistance, it can inhibit corrosion under low Cl concentrations, leading to immediate re-passivation and no observed hysteresis in polarization curves.
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This study delves into the atmospheric corrosion behavior of chromium-free complex-phase (CP) steel, specifically investigating the influence of wet/dry frequency and ratio in cyclic corrosion tests (CCT). The study employs a modified ISO 14993 standard CCT method, which involves salt spray, dry, and wet stages. After 15 and 30 CCT cycles, mass loss, maximum corrosion depth, and corrosion products were analyzed to gain insights into corrosion mechanisms.

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In this study, an Al-Mn-Zr alloy was designed and its microstructure and corrosion behavior compared after laser welding to that of AA3003. As the results of immersion and electrochemical tests showed, both alloys had a faster corrosion rate in the fusion zone than in the base metal. Laser welding caused interdendritic segregation, and spread the intermetallic compounds (IMCs) evenly throughout in the fusion zone.

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In order to predict the corrosion depth of a district heating pipeline, it is necessary to analyze various corrosion factors. In this study, the relationship between corrosion factors such as pH, dissolved oxygen, and operating time and corrosion depth was investigated using the Box-Behnken method within the response surface methodology. To accelerate the corrosion process, galvanostatic tests were conducted in synthetic district heating water.

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The automobile industry commonly uses cyclic corrosion tests (CCTs) to evaluate the durability of materials. However, the extended evaluation period required by CCTs can pose challenges in this fast-paced industry. To address this issue, a new approach that combines a CCT with an electrochemically accelerated corrosion test has been explored, to shorten the evaluation period.

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Soil corrosion is always a critical concern to corrosion engineering because of the economic influence of soil infrastructures as has been and has recently been the focus of spent nuclear fuel canisters. Besides corrosion protection, the corrosion prediction of the canister is also important. Advanced knowledge of the corrosion rate of spent nuclear fuel canister material in a particular environment can be extremely helpful in choosing the best protection method.

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In this work, a cerium/tetraethylenepentamine dithiocarbamate complex was synthesized and evaluated for the corrosion inhibition capability on an AA2024-T3 Al alloy in a 3.5% NaCl medium. The synthesized compounds were characterized via spectroscopic techniques.

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This study investigated the hydrogen embrittlement (HE) characteristics of advanced high-strength steels (AHSSs). Two different types of AHSSs with a tensile strength of 1.2 GPa were investigated.

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In this study, the cause of failure of a low-carbon steel pipe meeting standard KS D 3562 (ASTM A135), in a district heating system was investigated. After 6 years of operation, the pipe failed prematurely due to pitting corrosion, which occurred both inside and outside of the pipe. Pitting corrosion occurred more prominently outside the pipe than inside, where water quality is controlled.

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In this study, we performed metal (Ag, Ni, Cu, or Pd) electroplating of core-shell metallic Ag nanowire (AgNW) networks intended for use as the anode electrode in organic light-emitting diodes (OLEDs) to modify the work function (WF) and conductivity of the AgNW networks. This low-cost and facile electroplating method enabled the precise deposition of metal onto the AgNW surface and at the nanowire (NW) junctions. AgNWs coated onto a transparent glass substrate were immersed in four different metal electroplating baths: those containing AgNO for Ag electroplating, NiSO for Ni electroplating, CuPO for Cu electroplating, and PdCl for Pd electroplating.

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  • * This study proposes using calcareous deposits (layers made from calcium and magnesium) to reduce the current that causes corrosion by forming barriers at the pipeline's current entry points.
  • * Experimental results show that these deposits significantly decrease stray current, with the calcium carbonate (CaCO) layer being the most effective, providing a thick and dense barrier against corrosion.
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  • External damage to buried pipelines is primarily caused by corrosive elements in the soil, making it challenging to study due to the presence of multiple agents.
  • This study aims to assess the impact of pH, chloride, and sulfate on corrosion using a statistical approach called Response Surface Methodology (RSM), specifically the Box-Behnken design (BBD).
  • Through electrochemical tests, the research formulates an equation to predict corrosion current density based on varying concentrations of these three factors and analyzes their individual effects using response surface and contour plots.
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A new approach to the recycling of spent coffee grounds is described in which lignin, a chemical component of spent coffee, is used as an electrolyte additive in aluminum-air batteries. The effect of lignin on the performance of aluminum-air batteries has been investigated by weight loss measurement, galvanostatic discharge test, and electrochemical impedance spectroscopy (EIS). The corrosion inhibition efficiency is improved up to 37.

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Many research studies have been conducted on the corrosion inhibition performance of imidazole in acidic environments such as in the piping of a petrochemical plant. However, there has been no study on the effect of imidazole in alkaline conditions such as a local district water heating environment. Therefore, in this study, the effect of imidazole as a corrosion inhibitor on carbon steel weldment was investigated in alkaline district heating water.

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This study investigated the effect of Cr alloying element on the corrosion properties of automotive carbon steel (0.1C, 0.5Si, 2.

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Carbonaceous residues on copper pipes during the manufacturing process are known to be one of the main causes of pitting corrosion on copper pipes. This study examined the corrosion-inhibiting effect of benzotriazole (BTA) on C12200 copper pipes with carbonaceous film in synthetic tap water. In the absence of BTA, localized corrosion mechanisms due to galvanic corrosion, crevice corrosion, and oxygen-concentration cell were proposed in the boundary part of the carbonaceous film on the copper through X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) with energy dispersive spectrometer (EDS) analyses.

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Various studies have been conducted to better understand the long-term corrosion mechanism for steels in a soil environment. Here, electrochemical acceleration methods present the most efficient way to simulate long-term corrosion. Among the various methods, galvanostatic testing allows for accelerating the surface corrosion reactions through controlling the impressed anodic current density.

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  • High sensitivity detection of tumor markers like vascular endothelial growth factor (VEGF) is crucial for quick cancer diagnosis and treatment.
  • An electrochemical aptasensor utilizing nanocomposites of polyaniline (PANI) and carbon nanotubes (CNT) shows promise due to its cost-effectiveness and quantitative capabilities.
  • This aptasensor can detect VEGF at very low concentrations (as low as 0.4 pg/mL) and maintains stability and reproducibility, making it suitable for future non-invasive diagnostic applications.
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Several corrosion mitigation methods are generally applied to pipelines exposed to corrosive environments. However, in the case of pre-buried pipelines, the only option for corrosion inhibition is cathodic protection (CP). To apply CP, the required current should be defined even though the pipeline is covered with various oxide layers.

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This study investigated the optimum pickling conditions for improving the phosphatability of advanced high-strength steel (AHSS) using surface analysis and electrochemical measurements. To remove the SiO that forms on the surface of AHSS, 30 wt.% NHHF was added to the pickling solution, resulting in a significant reduction in the amount of SiO remaining on the surface of the AHSS.

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The low sheet resistance and high optical transparency of silver nanowires (AgNWs) make them a promising candidate for use as the flexible transparent electrode of light-emitting diodes (LEDs). In a perovskite LED (PeLED), however, the AgNW electrode can react with the overlying perovskite material by redox reactions, which limit the electroluminescence efficiency of the PeLED by causing the degradation of and generating defect states in the perovskite material. In this study, we prepared Ag-Ni core-shell NW electrodes using the solution-electroplating technique to realize highly efficient PeLEDs based on colloidal formamidinium lead bromide (FAPbBr) nanoparticles (NPs).

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Pre-stretching experiments were carried out on AZ31-0.5Ca magnesium alloy to alter the microstructure and texture for enhancing room-temperature formability. Compared to as-received alloy, the formability of a 5%-stretched sample was improved by 15%.

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This study examined the effect of corrosion on mechanical properties of welded carbon steel pipe in district heating water. To evaluate the corrosion properties, potentiodynamic tests were conducted and a galvanostatic test was used to accelerate corrosion. Tensile tests and microstructure observations were performed to figure out the degradation of the corroded region, and stress intensity factors were calculated.

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