scholarly journals Boric Acid as an Accelerator of Cerium Surface Treatment on Aluminum

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
K. Cruz-Hernández ◽  
S. López-Leon ◽  
F. J. Rodríguez-Gómez
Keyword(s):  
Boric Acid ◽  
Polarization Resistance ◽  
Immersion Time ◽  
Surface Characterization ◽  
Electrochemical Impedance ◽  
Electrochemical Techniques ◽  
Industrial Processes ◽  
Aerospace Manufacturing ◽  
Better Than ◽  
Anticorrosion Properties

Aluminum pieces are often used in various industrial processes like automotive and aerospace manufacturing, as well as in ornamental applications, so it is necessary to develop processes to protect these materials, processes that can be industrialized to protect the aluminum as well or better than chromate treatments. The purpose of this research is to evaluate boric acid as an accelerator by optimizing its concentration in cerium conversion coatings (CeCC) with 10-minute immersion time with a concentration of 0.1 g L−1over aluminum to protect it. The evaluation will be carried out by measuring anticorrosion properties with electrochemical techniques (polarization resistance,Rp, polarization curves, PC, and electrochemical impedance spectroscopy, EIS) in NaCl 3.5% wt. aqueous solution and surface characterization with scanning electron microscopy (SEM).

scholarly journals Corrosion and Corrosion Inhibition of High Strength Low Alloy Steel in 2.0 M Sulfuric Acid Solutions by 3-Amino-1,2,3-triazole as a Corrosion Inhibitor

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
El-Sayed M. Sherif ◽  
Adel Taha Abbas ◽  
D. Gopi ◽  
A. M. El-Shamy
Keyword(s):  
Sulfuric Acid ◽  
Corrosion Inhibition ◽  
Polarization Resistance ◽  
Immersion Time ◽  
Electrochemical Impedance ◽  
Hsla Steel ◽  
Electrochemical Techniques ◽  
High Strength ◽  
X Ray ◽  
Sulfuric Acid Solutions

The corrosion and corrosion inhibition of high strength low alloy (HSLA) steel after 10 min and 60 min immersion in 2.0 M H2SO4solution by 3-amino-1,2,4-triazole (ATA) were reported. Several electrochemical techniques along with scanning electron microscopy (SEM) and energy dispersive X-ray (EDS) were employed. Electrochemical impedance spectroscopy indicated that the increase of immersion time from 10 min to 60 min significantly decreased both the solution and polarization resistance for the steel in the sulfuric acid solution. The increase of immersion time increased the anodic, cathodic, and corrosion currents, while it decreased the polarization resistance as indicated by the potentiodynamic polarization measurements. The addition of 1.0 mM ATA remarkably decreased the corrosion of the steel and this effect was found to increase with increasing its concentration to 5.0 mM. SEM and EDS investigations confirmed that the inhibition of the HSLA steel in the 2.0 M H2SO4solutions is achieved via the adsorption of the ATA molecules onto the steel protecting its surface from being dissolved easily.

scholarly journals Green Approach to Corrosion Inhibition of Carbon Steel by Fucus spiralis extract in 1 M HCl Medium

2021 ◽  
Vol 12 (5) ◽  
pp. 7075-7091
Keyword(s):  
Carbon Steel ◽  
Corrosion Inhibitor ◽  
Surface Characterization ◽  
Electrochemical Impedance ◽  
Electrochemical Techniques ◽  
Adsorption Model ◽  
Corrosion Properties ◽  
Uv Visible ◽  
Fucus Spiralis ◽  
Hcl Medium

The extract of Fucus spiralis (FS) was tested as a corrosion inhibitor of carbon steel in a 1M HCl medium. The anti-corrosion properties were analyzed by gravimetric and electrochemical techniques such as potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS). The surface characterization of carbon steel submerged in the optimal solution was carried out using UV-Visible, UV-Vis-NIR, and Optical microscopy analyses. Electrochemical and gravimetric results demonstrated that inhibitory efficiencies increase with increasing inhibitor concentration and the efficiency reaches 87% at a concentration of 0.5 g/L. According to Tafel extrapolated polarisation measurements, the FS also worked as a mixed-type corrosion inhibitor and changed the mechanism of anodic reactions. EIS analysis showed that a depressed capacitive loop dominates the Nyquist plot of impedance and enhances the polarization resistance (Rp) to 161.9 Ω cm2 with a reduction of the double layer capacity (Cdl) of carbon steel to 61.8 μF/cm2. This protection is assured by an adsorption mechanism based on the isothermal Langmuir adsorption model, which positively affects the thermodynamic parameters. UV-Visible, UV-Vis-NIR analyses exhibited that inhibitor decreases the iron oxides like hematite, Magnetite, and Goethite, Maghemite, Lepidocrocite, δ-FeOOH of the metal surface and delays the dissolution of the bare metal of iron to the ferrous ions, notably that optical morphology showed that FS extract decreases the aggressivity of HCl.

Facile caffeine electrochemical detection via electrodeposited Ag nanoparticles with modifier polymers on carbon paste sensor at aqueous and micellar media

2020 ◽  
Vol 98 (4) ◽  
pp. 169-178 ◽  
Author(s):  
M. Shehata ◽  
S.M. Azab ◽  
A.M. Fekry
Keyword(s):  
Ag Nanoparticles ◽  
Surface Characterization ◽  
Electrochemical Impedance ◽  
Limit Of Detection ◽  
Electrochemical Techniques ◽  
Calibration Plot ◽  
Micellar Media ◽  
Carbon Paste ◽  
Detection Range ◽  
X Ray

The analysis and detection of caffeine (Caf) is very useful due to its widespread usage in several daily consumed beverages, food products, and pharmacological preparations with various physiological effects. The preparation of a newly electrodeposited Ag nanoparticles – cellulose acetate phthalate (CAP) – chitosan (Chit) modified carbon paste (ACCMCP) sensor for sensitive determination of Caf in 0.01 mol L−1 H3PO4 solution (pH 1.0–5.0) both in aqueous and micellar media (0.5 mmol L−1 SDS) was achieved. The interaction of Caf was monitored using electrochemical techniques such as cyclic voltammetry, differential pulse voltammetry, electrochemical impedance spectroscopy, and chronoamperometry, and surface characterization was carried out using X-ray diffraction, scanning electron microscope, and energy dispersive X-ray techniques. The linear detection range of Caf was between 4 and 500 μmol L−1 (r2 = 0.955) and the limit of detection obtained from the calibration plot was 0.252 μmol L−1. The sensor was applicable for detecting Caf in numerous real samples with recoveries from 98.03% to 101.60% without interference of any accompanying species, which ensures high method selectivity.

Electrochemical Investigation of the Effects of Acid Concentration and Dissolved Oxygen on the Corrosion Behavior of Austenitic Low-Nickel Stainless Steels in Citric Acid

2016 ◽  
Vol 835 ◽  
pp. 115-120
Author(s):  
Francis Mulimbayan ◽  
Manolo G. Mena
Keyword(s):  
Corrosion Resistance ◽  
Citric Acid ◽  
Dissolved Oxygen ◽  
Corrosion Behavior ◽  
Polarization Resistance ◽  
Electrochemical Impedance ◽  
Electrochemical Techniques ◽  
Open Circuit ◽  
Human Consumption ◽  
Face Centered Cubic

All materials which are intended to have in contact with food and other commodities produced or processed for human consumption are called food contact materials (FCM’s). Stainless steel (SS) – a widely known metallic FCM is used mainly in processing equipment, containers and household utensils. It is known for having numerous industrial and domestic applications worldwide due to its special characteristics of having notable corrosion resistance. However, this corrosion resistance is not all-encompassing since SS may still undergo degradation when subjected to a specific corrosion-inducing environment. SS may be classified according to its microstructure. If the atoms which make up the SS can be viewed as having a face-centered cubic structure, then the alloy is said to be austenitic. This SS grades include the conventional 300-series and the newly-developed 200-series. The former has superior corrosion resistance while the latter is far cheaper. In this study, the corrosion behavior of AISI 202 SS in two different levels of dissolved oxygen (O2) and three acid concentrations was investigated using electrochemical techniques, namely, open-circuit potential (OCP) measurements and electrochemical impedance spectroscopy (EIS). As the concentration of citric acid is increased, the measured OCP values of the alloy decreased and the polarization resistance (Rp) decreased, indicating decrease in alloy stability and decline in the corrosion resistance, respectively. With regards to effects of dissolved O2, results revealed that increasing the level of dissolved O2 has consequently increased the polarization resistance and shifted the OCP to more positive values. All the generated Nyquist plots exhibited a depressed capacitive loops indicating that corrosion in the designated solution occurred with charge transfer as the rate-determining step.

scholarly journals Evaluación de la degradación de superficies de fluorapatita mediante técnicas electroquímicas. (Degradation Assessment of Fluorapatite Surfaces using Electrochemical Techniques)

2015 ◽  
Vol 6 (1) ◽  
pp. 33 ◽  
Author(s):  
L. J. Reyes Jaimes ◽  
H. A. González Romero ◽  
A. Sandoval Amadora ◽  
D. Y. Peña Ballesteros ◽  
H. A. Estupiñán Durán
Keyword(s):  
Simulated Body Fluid ◽  
Body Fluid ◽  
Immersion Time ◽  
Electrochemical Impedance ◽  
Electrochemical Techniques ◽  
Active Surface ◽  
Apatite Formation ◽  
X Ray ◽  
Cathodic Electrodeposition ◽  
High Concentrations

ResumenSe evaluó el efecto del pH de fluido corporal simulado en la formación de apatitas y en la degradación de superficies de la aleación Ti6Al4V recubiertas con Fosfato de Calcio mediante la técnica de lectrodeposición catódica. Como variables de estudio se tomaron el pH del fluido corporal simulado y el tiempo de inmersión de los recubrimientos. Mediante microscopia electrónica de barrido, espectroscopia de energía dispersiva, difracción de rayos X y absorción atómica se pudo corroborar la formación de apatitas, y la degradación de los recubrimientos se evaluó mediante Espectroscopia de impedancia electroquímica y curvas de polarización potenciodinámicas. Los resultados obtenidos muestran que los recubrimientos tenían altas concentraciones de Fluorapatita (Ca5(PO4)3F) y que su formación se ve favorecida a medida que el pH del fluido corporal simulado y el tiempo de inmersión aumenta. Por otra parte, se obtuvo que las muestras evaluadas a pH de 7,2 son menos estables termodinámicamente, sin embargo, las evaluadas a 7,6 presentan una superficie más activa, por lo que se obtiene una mayor velocidad de degradación. AbstractThe pH eect of a Simulated Body Fluid in the apatite formation and the degradation of the Ti6Al4V alloy surfaces, coated by calcium phosphate obtained through cathodic electrodeposition was evaluated. The simulated body fluid pH and the coating immersion time were taken as variables. The formation of apatite was corroborated by Scanning Electron Microscopy, Energy Dispersive Spectroscopy, X Ray Diraction and Atomic Absorption Techniques. The coating degradation was assessed by the Electrochemical Impedance Spectroscopy and the Potential Dynamic Polarization Curves. The results have shown that the coatings had high concentrations of fluorapatite (Ca5(PO4)3F) and its formation was favored as the simulated body fluid pH and the immersion time increases. Moreover, it was found that the coatings samples evaluated at pH 7.2 were less thermodynamically steady, however, the evaluated coating at pH 7.6 exhibited a more active surface, so that a higher rate of degradation is obtained.

scholarly journals Effects of Immersion Time and 5-Phenyl-1H-tetrazole on the Corrosion and Corrosion Mitigation of Cobalt Free Maraging Steel in 0.5 M Sulfuric Acid Pickling Solutions

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
El-Sayed M. Sherif ◽  
Asiful H. Seikh
Keyword(s):  
Maraging Steel ◽  
Electron Spectroscopy ◽  
Polarization Resistance ◽  
Immersion Time ◽  
Electrochemical Impedance ◽  
Steel Corrosion ◽  
Polarization Data ◽  
Exposure Test ◽  
X Ray ◽  
Scanning Electron

The effect of exposure time and 5-phenyl-1H-tetrazole on the corrosion and corrosion mitigation of cobalt free maraging steel in 0.5 M H2SO4pickling solutions has been reported using electrochemical and spectroscopic investigations. Potentiodynamic polarization data showed that the increase of immersion time from 0 min to 120 min increases the corrosion rate and decreases the polarization resistance of the maraging steel. On the other hand, the addition of PHTA and the increase of its concentration decrease all the corrosion parameters of the steel at all exposure test periods. Electrochemical impedance spectroscopy measurements agreed with the obtained polarization data. Scanning electron spectroscopy and energy dispersive X-ray investigations confirmed that the inhibition of the steel corrosion is achieved via the adsorption of the PHTA molecules onto the steel precluding its surface from being dissolved.

Use and Limitations of Electrochemical Techniques for Investigating Microbiological Corrosion

CORROSION ◽  
1991 ◽  
Vol 47 (4) ◽  
pp. 308-318 ◽  
Author(s):  
S. C. Dexter ◽  
D. J. Duquette ◽  
O. W. Siebert ◽  
H. A. Videla
Keyword(s):  
Electrical Resistance ◽  
Polarization Resistance ◽  
Electrochemical Noise ◽  
Electrochemical Impedance ◽  
Electrochemical Techniques ◽  
Microbiologically Influenced Corrosion ◽  
Microbiological Corrosion ◽  
Pitting Potential ◽  
Linear Polarization Resistance ◽  
Cell Current

Abstract Electrochemical techniques such as: corrosion and critical pitting potential measurements, direct current potentiostatic and potentiodynamic polarization, linear polarization resistance, split-cell current measurements, electrochemical impedance, electrochemical noise, and electrical resistance probes are evaluated for use in investigating microbiologically influenced corrosion. Examples are given to illustrate the capabilities and limitations of each technique.

scholarly journals Immersion Behavior of Carbon Steel, Phosphate Carbon Steel and Phosphate and Painted Carbon Steel in Saltwater

Materials ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 188
Author(s):  
Costica Bejinariu ◽  
Diana-Petronela Burduhos-Nergis ◽  
Nicanor Cimpoesu
Keyword(s):  
Mechanical Properties ◽  
Corrosion Resistance ◽  
Carbon Steel ◽  
Polarization Resistance ◽  
Immersion Time ◽  
Electrochemical Impedance ◽  
Petroleum Industry ◽  
Paint Layer ◽  
Corrosion Process ◽  
Paper Study

The carbon steel is used in many areas due to its good mechanical properties; however, its low corrosion resistance presents a very important problem, for example, when carbon steel carabiners are used in the petroleum industry or navy, the possibility of an accident is higher due to carabiner failure. This phenomenon could occur as a consequence of the corrosion process which negatively affects mechanical properties. This paper study the possibility to improve its corrosion resistance by depositing on its surface a phosphate layer and a paint layer, and also aims to analyze the immersion behavior in saltwater of carbon steel, phosphate carbon steel, and phosphate and painted carbon steel. According to this study, by coating the carbon steel with a phosphate or paint layer, a higher polarization resistance is obtained in saltwater. Moreover, by electrochemical impedance spectroscopy (EIS), it was observed that the corrosion rate decreases with the increase of the immersion time. Meanwhile scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) revealed that the main compounds which formed on the sample’s surface were iron oxides or hydroxy-oxides, after immersion for a longer period. The overall results show that all types of deposited layers increase the corrosion resistance of C45 steel.

scholarly journals Corrosion Behavior of Some Timonb Alloys in Ringer Solution

2020 ◽  
Vol 71 (7) ◽  
pp. 187-196
Author(s):  
Maria Magdalena Pricopi ◽  
Romeu Chelariu ◽  
Nicolae Apostolescu ◽  
Doina-Margareta Gordin ◽  
Daniel Sutiman ◽  
...  
Keyword(s):  
Corrosion Behavior ◽  
Immersion Time ◽  
Open Circuit Potential ◽  
Electrochemical Impedance ◽  
Ph Value ◽  
Electrochemical Techniques ◽  
Ringer Solution ◽  
Open Circuit ◽  
Chemical Compositions ◽  
Solution Ph

The aim of this study was to investigate the influence of different process parameters as chemical composition, the pH value and immersion time on the corrosion of the some TiMoNb alloys, using different electrochemical techniques such as: cyclic voltammetry, open circuit potential (OCP) measurement, polarization curves and electrochemical impedance spectroscopy (EIS). The alloys were analyzed in the natural pH of the Ringer solution, but also with an acidic modification of the solution (ph = 4) and a basic modification (ph = 8). The more acidic values of pH, the more evident are differences between corrosion behavior of titanium-based alloys depending on their chemical compositions and immersion times.

scholarly journals Electrochemical Behavior of a Stainless Steel Superficially Modified with Nitrogen by Three-dimensional Ion Implantation

2021 ◽  
Vol 42 (1) ◽  
pp. e85772
Author(s):  
Felipe Sanabria-Martínez ◽  
Ely Dannier Valbuena Niño ◽  
Leidy Silvana Chacón Velasco ◽  
Hugo Armando Estupiñán Duran
Keyword(s):  
Stainless Steel ◽  
Ion Implantation ◽  
Polarization Resistance ◽  
Electrochemical Impedance ◽  
Electrochemical Techniques ◽  
Three Dimensional ◽  
Electrochemical Corrosion ◽  
Uniform Corrosion ◽  
Operation Conditions ◽  
Aisi 420

Martensitic-grade stainless steels are widely used in diverse industrial and surgical applications, despite their natural tendency to suffer local and uniform corrosion when continuously exposed to aggressive operation conditions. In order to enhance their surface properties, this paper characterized the performance, in saline solutions, of AISI 420 stainless steel, which was surface-modified by three-dimensional ion implantation using electrochemical techniques. The surface of the samples was implanted with ionized nitrogen particles with an energy of 10 keV, varying the implantation time between 30 and 90 minutes. After the surface treatment, the samples were exposed to a NaCl 3% (w/w) aqueous solution for 21 days. Tafel extrapolation, linear polarization resistance, and electrochemical impedance spectroscopy tests were performed, with the purpose of quantifying the effect of the ion implantation technique against electrochemical corrosion. To establish a comparison, the same tests were also performed on non-treated samples. The results indicated an increase in the corrosion potential, polarization resistance, and a decrease in the current density of implanted samples, thus demonstrating that, by delaying corrosive activity, traditional ion implantation offers better protection against electrochemical corrosion in AISI 420 stainless steel samples implanted with nitrogen.

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