scholarly journals Optimizing the Required Cathodic Protection Current for Pre-Buried Pipelines Using Electrochemical Acceleration Methods

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 579
Author(s):  
Nguyen-Thuy Chung ◽  
Min-Sung Hong ◽  
Jung-Gu Kim
Keyword(s):  
Current Density ◽  
Cathodic Protection ◽  
Potentiodynamic Polarization ◽  
Corrosion Current Density ◽  
Electrochemical Impedance ◽  
Operating Time ◽  
Corrosion Current ◽  
Buried Pipelines ◽  
Soil Corrosion ◽  
Surface Corrosion

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. In this study, an electrochemical acceleration test was used to investigate the synthetic soil corrosion of a pre-buried pipeline. Potentiodynamic polarization experiments were first conducted to ascertain the corrosion current density in the environment, and galvanostatic measurements were performed to accelerate corrosion according to the operating time. In addition, corrosion current density and the properties of the rust layer were investigated via potentiodynamic polarization tests and electrochemical impedance spectroscopy (EIS) tests. The variation in surface corrosion was subsequently analyzed via optical microscopy (OM) and X-ray diffraction (XRD) measurements. Finally, an empirical equation for the optimized CP current requirement, according to the pipeline service time, was derived. This equation can be applied to any corroded pipeline.

Electrochemical Characteristics of Al-Based Coating on Magnesium Alloy Fabricated by Supersonic Particles Deposition

2013 ◽  
Vol 756-759 ◽  
pp. 85-88
Author(s):  
Xiao Ming Wang ◽  
Sheng Zhu ◽  
Qing Chang ◽  
Guo Feng Han
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Magnesium Alloy ◽  
Impedance Spectroscopy ◽  
Current Density ◽  
Corrosion Current Density ◽  
Corrosion Potential ◽  
Electrochemical Impedance ◽  
Corrosion Current ◽  
Electrochemical Characteristics ◽  
Order Of Magnitude

Al-based coating on ZM5 magnesium alloy was prepared by Supersonic Particles Deposition (SPD). Electrochemical working station was utilized to test polarization curve, corrosion potential and electrochemical impedance spectroscopy etc. The results indicted that corrosion potential of Al-Si coating was about-767.6mV, much higher than that of ZM5 Mg-substrate; And corrosion current density of the coating sample decreased three order of magnitude than that of the uncoated. Compared to Mg-substrate, the radius of capacitive impedance arc of the coating enlarged and impedance modulus improved two order of magnitude.

Electrochemical Corrosion Behavior of Iron Aluminides in Sulfuric Acid

2020 ◽  
Vol 1012 ◽  
pp. 395-400
Author(s):  
Pedro Paiva Brito ◽  
Carlos Trivellato de Carvalho Filho ◽  
Gabriela de Andrade Oliveira
Keyword(s):  
Current Density ◽  
Corrosion Current Density ◽  
Electrochemical Impedance ◽  
Electrochemical Corrosion ◽  
Corrosion Current ◽  
Passive Behavior ◽  
Corrosion Evaluation ◽  
Electrochemical Corrosion Behavior ◽  
Work Samples ◽  
Passive Current

In the present work, samples of a binary intermetallic alloy (Fe3Al) with 26at.%Al were submitted to electrochemical corrosion evaluation in a 0.5M H2SO4 solution containing naturally dissolved oxygen. The corrosion resistance was evaluated by applying linear polarization, electrochemical impedance spectroscopy and potentiodynamic polarization at 22 and 35°C. The results obtained revealed that in both conditions the material exhibits active-passive behavior. Heating to 35°C did not alter the passivity characteristics of the alloy (passivation range and passive current density), but elevated the corrosion current density and the critical current density. The polarization resistance of the samples was also decreased with temperature, following the trend observed for the corrosion current density.

High corrosion resistance Ni-reduced graphene oxide nanocomposite coating

2016 ◽  
Vol 34 (5-6) ◽  
pp. 305-312 ◽  
Author(s):  
Seyed Ali Hosseini Khorasani ◽  
Sohrab Sanjabi
Keyword(s):  
Corrosion Resistance ◽  
Graphene Oxide ◽  
Composite Coating ◽  
Current Density ◽  
Corrosion Current Density ◽  
Electrochemical Impedance ◽  
Corrosion Current ◽  
Nanocomposite Coating ◽  
High Corrosion Resistance ◽  
High Corrosion

AbstractThis paper presents a high corrosion resistance Ni-graphene composite coating fabricated by co-electrodeposition on Cu substrate. First, GO was synthesized by improved Hummers’ method, and then different concentrations of GO aqueous solution were introduced to Ni Watt’s bath. During electrodeposition, GO and Ni ions were reduced simultaneously to form composite coating. The phase structure and morphology were covered by X-ray diffraction and scanning electron microscopy analysis, respectively. Atomic force microscopy (AFM) was employed to identify the surface topography of the coatings. Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), and electrochemical impedance spectroscopy (EIS) were used to study the synthesis of GO and its reduction during the plating process. Corrosion resistance of nanocomposite and that of pure Ni coating were compared by applying potentiodynamic polarization spectroscopy (PDS). The results showed that by increasing the amount of graphene oxide in solution, there has been a significant reduction in corrosion current density. As the EIS result showed, the high amount of GO reduction was obtained in GO concentration of 0.6 mg ml−1 and current density of 8 A dm−2. It is in a good agreement with data obtained from PDS. Analyses showed that the corrosion current density of corresponding coating was improved up to 0.2 μA cm−2, which means an improvement of about 100 times compared to pure Ni coating.

scholarly journals Corrosion Behavior and Biological Activity of Micro Arc Oxidation Coatings with Berberine on a Pure Magnesium Surface

Coatings ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 837
Author(s):  
Liting Mu ◽  
Zhen Ma ◽  
Jingyan Wang ◽  
Shidan Yuan ◽  
Muqin Li
Keyword(s):  
Biological Activity ◽  
Current Density ◽  
Photoelectron Spectroscopy ◽  
Corrosion Current Density ◽  
Electrochemical Impedance ◽  
Corrosion Current ◽  
Pure Magnesium ◽  
X Ray ◽  
Micro Arc Oxidation ◽  
Assembly Technology

Bone tissue repair materials can cause problems such as inflammation around the implant, slow bone regeneration, and poor repair quality. In order to solve these problems, a coating was prepared by ultrasonic micro-arc oxidation and self-assembly technology on a pure magnesium substrate. We studied the effect of berberine on the performance of the ultrasonic micro-arc oxidation/polylactic acid and glycolic acid copolymer/berberine (UMAO/PLGA/BR) coating. The chemical and morphological character of the coating was analyzed using scanning electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The corrosion properties were studied by potentiodynamic polarization and electrochemical impedance spectroscopy in a simulated body fluid. The cumulative release of drugs was tested by high-performance liquid chromatography. The results indicate that different amounts of BR can seal the corrosion channel to different extents. These coatings have a self-corrosion current density (Icorr) at least one order of magnitude lower than the UMAO coatings. When the BR content is 3.0 g/L, the self-corrosion current density of the UMAO/PLGA/BR coatings is the lowest (3.14 × 10−8 A/cm2) and the corrosion resistance is improved. UMAO/PLGA/BR coatings have excellent biological activity, which can effectively solve the clinical problem of rapid degradation of pure magnesium and easy infection.

Corrosion Behavior of Cobalt Alloy Coating in NaCl Solution

2020 ◽  
Vol 993 ◽  
pp. 1086-1094
Author(s):  
Yue Hou ◽  
Hai Yan Chen ◽  
Li Fan ◽  
Yu Rong Xu ◽  
Qian Cheng ◽  
...  
Keyword(s):  
Current Density ◽  
Corrosion Current Density ◽  
Electrochemical Impedance ◽  
Corrosion Behaviour ◽  
Alloy Coating ◽  
Corrosion Current ◽  
Eutectic Structure ◽  
Open Circuit ◽  
The Self ◽  
Nacl Solution

Two kinds of Co-based coatings were obtained through the laser cladding (LC) and plasma transfer arc (PTA) process. The phase composition and microstructure of the coatings were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The corrosion behaviour of the different Co-based alloy coatings in 3.5wt% NaCl solution were compared by means of open-circuit potential (OCP), polarization curve and electrochemical impedance spectroscopy (EIS). XRD and SEM measurements demonstrated that the microstructures of the two different Co-based coatings were composed of primary solid solution γ-Co and eutectic structure Cr23C6, whereas, fish-bone typed (CoCrW)6C was also detected in the coating produced by PTA. The polarization curves and EIS results showed that in 3.5wt% NaCl solution, the passivation zones of the two coatings occurred obviously, the self-corrosion potential of the two coatings shifted to the right, and the self-corrosion current density was much smaller than that of the substrate. In addition, the Co-based coating made by LC showed lower corrosion current density and larger diameter of a capacitive arc than that of Co-based coating produced by PTA, indicating the LC coating had the best corrosion resistance in the three samples.

Preparation and Properties of Chrome-Free Colored Na3AlF6 Conversion Coating on Aluminum Alloy

2012 ◽  
Vol 490-495 ◽  
pp. 3527-3530 ◽  
Author(s):  
Ai Hua Yi ◽  
Wen Fang Li ◽  
Jun Du ◽  
Song Lin Mu
Keyword(s):  
Corrosion Resistance ◽  
Aluminum Alloy ◽  
Current Density ◽  
Potentiodynamic Polarization ◽  
Corrosion Current Density ◽  
Corrosion Current ◽  
Conversion Coating ◽  
Film Forming ◽  
Polarization Test ◽  
Main Component

By adding tannic acid and film-forming accelerator in the treatment solution containing titanium and zirconium ions, a golden conversion coating on the surface of aluminum alloy was prepared. The main component and corrosion resistance of the conversion coating were characterized by means of EDS, SEM, XRD and electrochemical workstation. The conversion coating was golden and showed as uniform cubical crystal. results also showed that the main component of the conversion coating was Na3AlF6. In potentiodynamic polarization test, the corrosion current density of the aluminum alloy decreases to 0.083 A•cm-2 from 5.894 A•cm-2, which indicated an obvious improvement of corrosion resistance.

scholarly journals Polarization and EIS studies to evaluate the effect of aluminum concentration on the corrosion behavior of SAC105 solder alloy

2018 ◽  
Vol 35 (4) ◽  
pp. 694-701 ◽  
Author(s):  
N. K. Liyana ◽  
M. A. Fazal ◽  
A. S. M. A. Haseeb
Keyword(s):  
Solder Alloy ◽  
Corrosion Behavior ◽  
Current Density ◽  
Corrosion Current Density ◽  
Electrochemical Impedance ◽  
Corrosion Current ◽  
Aluminum Concentration ◽  
Nacl Solution ◽  
Sac105 Solder ◽  
Eis Measurements

Abstract This paper presents an investigation on corrosion behavior of Sn-1.0Ag-0.5Cu-XAl (X = 0, 0.1, 0.5, 1.0) by means of polarization and electrochemical impedance spectroscopy (EIS) measurements in 3.5 wt.% NaCl solution. The results show that addition of aluminum into SAC105 shifts the corrosion current density and passivation current density towards more positive values. It is also found that with an increase in aluminum concentration in SAC105 solder alloy, the corrosion current density increases and polarization resistance decreases. This suggests that SAC105 with the highest concentration of Al has the lowest corrosion resistance. In this case, the corrosion behavior seems to be attributed to anodic dissolution of aluminum and Sn-matrix.

The tribological and corrosion behavior of TiO2 coatings deposited by the electrophoretic deposition process

2019 ◽  
Vol 234 (6) ◽  
pp. 1231-1238
Author(s):  
Hafedh Dhiflaoui ◽  
Kaouther Khlifi ◽  
Najoua Barhoumi ◽  
Ahmed Ben Cheikh Larbi
Keyword(s):  
Current Density ◽  
Potentiodynamic Polarization ◽  
Corrosion Current Density ◽  
Corrosion Current ◽  
Deposition Process ◽  
Atomic Ratio ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Experimental Findings

TiO2 coatings have recently been used as corrosion resistant materials to protect metals in several environments. In this study, the microstructure, phase composition and morphology under different voltages (20, 30 and 40 V) were investigated using scanning electron microscopy (SEM), X-ray diffraction (XRD) and atomic force microscopy (AFM), respectively. The coating corrosion performance was examined by potentiodynamic polarization in 3.5 wt% NaCl solution. Experimental findings indicate that the thickness and cracks of the coating rise by increasing voltage. Energy dispersive X-ray spectroscopy results show that the atomic ratio Ti/O of the coating has an almost constant ratio. Obviously, the defects and cracks on the deposited coatings resulted in corrosive attack due to a considerable increase of the corrosion current density noticed during potentiodynamic polarization experiments. The film produced under 30 V exhibited the lowest corrosion current density [Formula: see text] value of 0.21 µA cm−2 as well as the lowest corrosion potential ([Formula: see text] value of −111.89 mV, which was attributed mainly to the significant decrease of micro-pore density in the coating.

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