Evaluation of Polymeric Coatings in CO2 Containing Environment

2019 ◽  
Vol 965 ◽  
pp. 133-141
Author(s):  
Rayane Z.C. Demoner ◽  
Alexandre R.P. Castro ◽  
Adriana L. Barros ◽  
J.P. Quintela ◽  
Jefferson R. de Oliveira ◽  
...  
Keyword(s):  
Electrochemical Impedance ◽  
Electrochemical Techniques ◽  
Polymeric Coating ◽  
Metallic Surface ◽  
Polymeric Coatings ◽  
X Ray Diffraction ◽  
X Ray ◽  
Linear Polarization Resistance ◽  
Weight Loss Method ◽  
Loss Method

Two types of polymeric coating were applied on an AISI 1020 steel, where one of them was reinforced by carbon nanotubes, with the objective of protection against corrosion in a medium containing saline solution, NaCl 3% wt satured with CO2, at 75 bar and tested at 50oC and 75oC for 360 hours. Electrochemical techniques, such as Linear Polarization Resistance, (LPR), Electrochemical Impedance Spectroscopy (EIS), Tafel curves and weight loss method, were used for coating evaluation performance. Scanning Electron Microscopy (SEM), X-ray diffraction (XRD) and energy dispersive spectroscopy (EDS) were used to determine both the morphology and chemical composition of the layer formed on the analyzed surfaces. The coating adhesion to metallic surface was evaluated using pull-off test according to ASTM D4541-09. For the studied conditions, the results obtained showed that there was no adequate coating protection, occurring failures and indicating that both coatings may not be used in the tested conditions.

scholarly journals Corrosion Performance of AISI-309 Exposed to Molten Salts V2O5-Na2SO4at 700°C Applying EIS andRpElectrochemical Techniques

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
E. F. Diaz ◽  
C. Cuevas-Arteaga ◽  
N. Flores-García ◽  
S. Mejía Sintillo ◽  
O. Sotelo-Mazón
Keyword(s):  
Molten Salts ◽  
Electrochemical Impedance ◽  
Electrochemical Techniques ◽  
Metallic Surface ◽  
Corrosion Performance ◽  
Potentiodynamic Polarization Curve ◽  
Linear Polarization Resistance ◽  
Second Stage ◽  
Tafel Slopes ◽  
Bode Plots

The corrosion performance of AISI-309 exposed 5 days to molten salts 50 mol% V2O5-50 mol% Na2SO4at 700°C is reported in this paper. Such evaluation was made using three electrochemical techniques: potentiodynamic polarization curve (PC), electrochemical impedance spectroscopy (EIS), and linear polarization resistance (Rp). FromPC, the Tafel slopes,Icorr, andEcorrwere obtained. From Nyquist and Bode plots, it was possible to determine two different stages; the first one showed just one loop, which indicated the initial formation of Cr2O3layer over the metallic surface; after that, the dissolution of Cr2O3formed a porous layer, which became part of the corrosion products; at the same time a NiO layer combined with sulfur was forming, which was suggested as the second stage, represented by two capacitive loops. EIS plots were in agreement with the physical characterization made from SEM and EDS analyses. Fitting of EIS experimental data allowed us to propose two electrical circuits, being in concordance with the corrosion stages. Parameters obtained from the simulation of EIS data are also reported. From the results, it was stated that AISI-309 suffered intergranular corrosion due to the presence of sulfur, which diffused to the metallic surface through a porous Cr2O3layer.

scholarly journals Green Corrosion Inhibitors for Copper in HCl and H2SO4 Solution - A Review

2021 ◽  
Vol 9 (VI) ◽  
pp. 353-361
Author(s):  
R. T. Vashi
Keyword(s):  
Weight Loss ◽  
Electrochemical Impedance ◽  
Electrochemical Techniques ◽  
Energy Dispersive ◽  
Effect Of Temperature ◽  
Metallic Surface ◽  
Electrochemical Impedance Spectra ◽  
X Ray ◽  
Surface Corrosion ◽  
Chemical Attack

Corrosion is the deterioration of metal by chemical attack or reaction with its environment. It is a constant and continuous problem, often difficult to eliminate completely. Prevention would be more practical and achievable than complete elimination. Recently, a huge interested for the use of naturally occurring inhibitors extracted from plants have been emerged. Most of the natural products are non-toxic, biodegradable and readily available due to environmental concerns. The inhibitor is chemically adsorbed on the surface of the metal and forms a protective thin film with inhibitor effect or by combination between inhibitor ions and metallic surface. Corrosion of copper and its inhibition was analyzed by weight loss (Gravimetric), effect of temperature and time of immersion methods. Electrochemical methods such as, Potentiodynamic polarization and Electrochemical Impedance Spectra (EIS) were employed. The protective films formed on metal surface have been analyzed by various techniques such as Scanning Electron Microscope (SEM), Energy dispersive X-ray spectrometry (EDS) and. Atomic Force Microscopy (AFM), Fourier transform infrared spectroscopy (FT-IR), UV-Visible spectra, X-ray Diffraction spectroscopy (XRD), Energy Dispersive X-ray Spectroscopy (EDX), electrochemical frequency modulation (EFM) techniques. The results obtained from weight loss and electrochemical techniques were in good agreement. In this review paper, research works produced over the past background on the corrosion of copper in various medium and their corrosion inhibition by using a various green inhibitors were presented.

The Accelerated Corrosion of Elemental Sulfur for Carbon Steel in Wet H2S Environment

2011 ◽  
Vol 117-119 ◽  
pp. 999-1002
Author(s):  
Shu Qi Zheng ◽  
Chun Yu Li ◽  
Chang Feng Chen
Keyword(s):  
Weight Loss ◽  
Carbon Steel ◽  
Corrosion Rate ◽  
Elemental Sulfur ◽  
X Ray Diffraction ◽  
Accelerated Corrosion ◽  
X Ray ◽  
Weight Loss Method ◽  
Loss Method

The accelerated corrosion action of sulfur for carbon steel in wet H2S environment was studied by simulating the actual serviced environment. The weight-loss method, SEM, EDS and X-ray diffraction techniques are used to analyze the corrosion rate, the structure and the composition of the corrosion production formed in the environments. The results show that sulfur aggravated the corrosion sharply in wet H2S environment.

Hot Corrosion Monitoring of Waste Incineration Corrosion Processes Using Electrochemical Techniques

2006 ◽  
Vol 522-523 ◽  
pp. 531-538 ◽  
Author(s):  
F.J. Pérez ◽  
J. Nieto ◽  
J.A. Trilleros ◽  
M.P. Hierro
Keyword(s):  
Electrochemical Impedance ◽  
Electrochemical Techniques ◽  
Waste Incineration ◽  
Corrosion Monitoring ◽  
Spinel Oxide ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cr2o3 Scale ◽  
Electrochemical Processes ◽  
Salt Mixtures

In order to evaluate the damage of molten salt mixtures in waste incineration environments, the alloy 625 was exposed to a molten KCl-ZnCl2 mixture at 650 °C for 200 hours. The corrosion process was monitored by electrochemical impedance spectroscopy (EIS). After exposure the corrosion products were analyzed by X-ray diffraction and SEM. Two different electrochemical impedance models were found to describe the electrochemical processes. In the early stages of corrosion the alloy developed a protective Cr2O3 scale which turned into a porous spinel oxide scale after 100 hours.

scholarly journals Fabrication of h-MoO3 Nanorods and the Properties of the MoO3/WEP Composite Coatings Research

2021 ◽  
Vol 5 (8) ◽  
pp. 207
Author(s):  
Ying Zhou ◽  
Cuihuan Song ◽  
Zhixiang Chen ◽  
Qixin Zhou
Keyword(s):  
Electrochemical Impedance ◽  
Composite Coatings ◽  
Polymeric Coating ◽  
Test Results ◽  
X Ray Diffraction ◽  
One Dimensional ◽  
X Ray ◽  
Waterborne Epoxy ◽  
Waterborne Epoxy Resin ◽  
Synthesis Methodology

In this study, we prepared a novel coating composed of hexagonal molybdenum oxide (h-MoO3) nanofiller and waterborne epoxy resin (WEP) to provide corrosion protection. We optimized the h-MoO3 nanorod synthesis methodology first by changing different parameters (pH, temperature, etc.). Furthermore, the as-prepared h-MoO3 rods were characterized using a scanning electron microscope (SEM) and X-ray diffraction (XRD). Finally, the electrochemical impedance spectroscopy (EIS) test results verified that the anticorrosive performance of the composite coatings was improved by incorporation of low content of MoO3 nanofiller (0.5 wt.%) compared to pure WEP sample. This developed composite will provide a new insight for the design and fabrication of one-dimensional (1D) nanomaterial (e.g., nanorod) reinforced epoxy coating and other polymeric coating processes.

Effect of Zn Content on Structure, Roughness and Corrosion Behavior of Zn-Ni Alloys

2019 ◽  
Vol 17 (17) ◽  
pp. 17-22
Author(s):  
Hayette Faid
Keyword(s):  
Corrosion Behavior ◽  
Electrochemical Impedance ◽  
Stripping Voltammetry ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ni Alloys ◽  
Sulfate Bath ◽  
Zn Content ◽  
Polarization Test ◽  
Δ Phase

AbstractIn this work, Zn-Ni alloys have been deposited on steel from sulfate bath, by electrodeposition method. The effect of Zn content on deposits properties was studied by cyclic voltammetry (CV), chronoaperometry (CA), linear stripping voltammetry (ALSV) and diffraction (XRD) and scanning electronic microscopy (SEM). The corrosion behavior in 3.5 wt. NaCl solution was examined using anodic polarization test and electrochemical impedance spectroscopy. X-ray diffraction of show that Zn-Ni alloys structure is composed of δ phase and γ phase, which increase with the decrease of Zn content in deposits. Results show that deposits obtained from bath less Zn2+ concentration exhibited better corrosion resistance.

Characterizations of Synthetic 8mol% YSZ with Comparison to 3mol %YSZ for HT-SOFC

2020 ◽  
Vol 38 (4A) ◽  
pp. 491-500
Author(s):  
Abeer F. Al-Attar ◽  
Saad B. H. Farid ◽  
Fadhil A. Hashim
Keyword(s):  
Ionic Conductivity ◽  
Electrochemical Impedance ◽  
Structural Information ◽  
Impedance Analysis ◽  
High Energy ◽  
Yttria Stabilized Zirconia ◽  
X Ray Diffraction ◽  
Stabilized Zirconia ◽  
Powder Morphology ◽  
X Ray

In this work, Yttria (Y2O3) was successfully doped into tetragonal 3mol% yttria stabilized Zirconia (3YSZ) by high energy-mechanical milling to synthesize 8mol% yttria stabilized Zirconia (8YSZ) used as an electrolyte for high temperature solid oxide fuel cells (HT-SOFC). This work aims to evaluate the densification and ionic conductivity of the sintered electrolytes at 1650°C. The bulk density was measured according to ASTM C373-17. The powder morphology and the microstructure of the sintered electrolytes were analyzed via Field Emission Scanning Electron Microscopy (FESEM). The chemical analysis was obtained with Energy-dispersive X-ray spectroscopy (EDS). Also, X-ray diffraction (XRD) was used to obtain structural information of the starting materials and the sintered electrolytes. The ionic conductivity was obtained through electrochemical impedance spectroscopy (EIS) in the air as a function of temperatures at a frequency range of 100(mHz)-100(kHz). It is found that the 3YSZ has a higher density than the 8YSZ. The impedance analysis showed that the ionic conductivity of the prepared 8YSZ at 800°C is0.906 (S.cm) and it was 0.214(S.cm) of the 3YSZ. Besides, 8YSZ has a lower activation energy 0.774(eV) than that of the 3YSZ 0.901(eV). Thus, the prepared 8YSZ can be nominated as an electrolyte for the HT-SOFC.

scholarly journals Effect of Molybdenum Content on the Corrosion and Microstructure of Low-Ni, Co-Free Maraging Steels

Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 852
Author(s):  
Asiful H. Seikh ◽  
Hossam Halfa ◽  
Mahmoud S. Soliman
Keyword(s):  
Corrosion Resistance ◽  
Electrochemical Impedance ◽  
Microstructural Analysis ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Alloying Element ◽  
X Ray ◽  
Maraging Steels ◽  
Eds Analysis ◽  
Electroslag Refining

Molybdenum (Mo) is an important alloying element in maraging steels. In this study, we altered the Mo concentration during the production of four cobalt-free maraging steels using an electroslag refining process. The microstructure of the four forged maraging steels was evaluated to examine phase contents by optical microscopy, scanning electron microscopy (SEM), and X-ray diffraction (XRD) analysis. Additionally, we assessed the corrosion resistance of the newly developed alloys in 3.5% NaCl solution and 1 M H2SO4 solution through potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques. Furthermore, we performed SEM and energy-dispersive spectroscopy (EDS) analysis after corrosion to assess changes in microstructure and Raman spectroscopy to identify the presence of phases on the electrode surface. The microstructural analysis shows that the formation of retained austenite increases with increasing Mo concentrations. It is found from corrosion study that increasing Mo concentration up to 4.6% increased the corrosion resistance of the steel. However, further increase in Mo concentration reduces the corrosion resistance.

Few-Layered MoS2 Nanostructures for Highly Efficient Visible Light Photocatalysis

NANO ◽  
2016 ◽  
Vol 11 (10) ◽  
pp. 1650114 ◽  
Author(s):  
Dan Li ◽  
Jianwei Li ◽  
Caiqin Han ◽  
Xinsheng Zhao ◽  
Haipeng Chu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Electrochemical Impedance ◽  
X Ray Diffraction ◽  
Electron Hole ◽  
Electrochemical Impedance Spectra ◽  
X Ray ◽  
Transmission Electron ◽  
Electron Hole Pair

Few-layered MoS2 nanostructures were successfully synthesized by a simple hydrothermal method without the addition of any catalysts or surfactants. Their morphology, structure and photocatalytic activity were characterized by X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy, transmission electron microscopy, electrochemical impedance spectra and UV-Vis absorption spectroscopy, respectively. These results show that the MoS2 nanostructures synthesized at 180[Formula: see text]C exhibit an optimal visible light photocatalytic activity (99%) in the degradation of Rhodamine B owing to the relatively easier adsorption of pollutants, higher visible light absorption and lower electron–hole pair recombination.

Structure and Electrochemical Behavior of Plasma-Sprayed LSGM Electrolyte Films

2002 ◽  
Vol 756 ◽  
Author(s):  
H. Zhang ◽  
X. Ma ◽  
J. Dai ◽  
S. Hui ◽  
J. Roth ◽  
...  
Keyword(s):  
Electrochemical Behavior ◽  
Electrochemical Impedance ◽  
Amorphous Structure ◽  
Solid Oxide ◽  
X Ray Diffraction ◽  
X Ray ◽  
Spray Process ◽  
Plasma Spray Process ◽  
Electrolyte Film ◽  
Plasma Sprayed

ABSTRACTAn intermediate temperature solid oxide fuel cell (SOFC) electrolyte film of La0.8Sr 0.2Ga0.8Mg0.2O2.8 (LSGM) was fabricated using a plasma spray process. The microstructure and phase were investigated using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The electrochemical behavior of the thermal sprayed LSGM film was investigated using electrochemical impedance spectroscopy (EIS). The study indicates that thermal spray can deposit a dense LSGM layer. It was found that the rapid cooling in the thermal process led to an amorphous or poor crystalline LSGM deposited layer. This amorphous structure has a significant effect on the performance of the cell. Crystallization of the deposited LSGM layer was observed during annealing between 500–600 °C. After annealing at 800 °C, the ionic conductivity of the sprayed LSGM layer can reach the same level as that of the sintered LSGM.

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