scholarly journals Effect of Nd3+ Ion Concentration on the Corrosion Resistance of API X70 Steel in Chloride-Rich Environments

2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
D. M. Martinez de la Escalera ◽  
J. J. Ramos-Hernandez ◽  
E. Porcayo-Palafox ◽  
J. Porcayo-Calderon ◽  
J. G. Gonzalez-Rodriguez ◽  
...  
Keyword(s):  
Open Circuit Potential ◽  
Inhibition Efficiency ◽  
Electrochemical Impedance ◽  
Electrochemical Techniques ◽  
Protective Layer ◽  
Open Circuit ◽  
Chloride Ions ◽  
Ion Concentration ◽  
Linear Polarization Resistance ◽  
Potentiodynamic Polarization Curves

In this study, the effect of the addition of Nd3+ ions as a corrosion inhibitor of the API X70 steel in a medium rich in chlorides was evaluated. The performance of the Nd3+ ions was evaluated by means of electrochemical techniques such as potentiodynamic polarization curves, open circuit potential measurements, linear polarization resistance, and electrochemical impedance spectroscopy, as well as by means of scanning electron microscopy and EDS measurements. The results showed that Nd3+ ions reduce the corrosion rate of steel at concentrations as low as 0.001 M Nd3+. At higher concentrations, the inhibition efficiency was only slightly affected although the concentration of chloride ions was increased by the addition of the inhibitor. The adsorption of the Nd3+ ions promotes the formation of a protective layer of oxides/hydroxides on the metal surface, thereby reducing the exchange rate of electrons. Nd3+ ions act as a mixed inhibitor with a strong predominant cathodic effect.

scholarly journals Electrochemical Performance of Ti-Based Commercial Biomaterials

2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
E. Porcayo-Palafox ◽  
S. I. Carrera-Chavez ◽  
S. R. Casolco ◽  
J. Porcayo-Calderon ◽  
V. M. Salinas-Bravo
Keyword(s):  
Polarization Resistance ◽  
Open Circuit Potential ◽  
Electrochemical Impedance ◽  
Open Circuit ◽  
Titanium Implants ◽  
Nacl Solution ◽  
Linear Polarization Resistance ◽  
Potentiodynamic Polarization Curves ◽  
Commercially Pure ◽  
Thermomechanical Processes

In order to determine the electrochemical behavior against the corrosion of different commercial biomaterials, in this study the results of the evaluation of different titanium implants are reported. The commercial implants evaluated were purchased randomly with different suppliers. The different biomaterials were subjected to studies of potentiodynamic polarization curves, open circuit potential measurements, linear polarization resistance measurements, and electrochemical impedance spectroscopy measurements in a 0.9% NaCl solution. The results showed that the chemical composition of the biomaterials corresponds to commercially pure Ti or to the alloy Ti6Al4V. In addition, although all the biomaterials showed a high resistance to corrosion, notable differences were observed in their performance. These differences were associated with the thermomechanical processes during the manufacture of the biomaterial, which affected its microstructure.

scholarly journals Inhibition Effect of Glycerol on the Corrosion of Copper in NaCl Solutions at Different pH Values

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Santos Lorenzo Chi-Ucán ◽  
Andrea Castillo-Atoche ◽  
Pedro Castro Borges ◽  
José Antonio Manzanilla-Cano ◽  
Gerardo González-García ◽  
...  
Keyword(s):  
Open Circuit Potential ◽  
Inhibition Efficiency ◽  
Electrochemical Impedance ◽  
Electrochemical Techniques ◽  
Impedance Analysis ◽  
Inhibitory Effect ◽  
Open Circuit ◽  
Copper Corrosion ◽  
Inhibition Effect ◽  
Ph Values

The inhibitory effect of glycerol on copper corrosion in aerated NaCl (0.5 M) solutions at three pH values (4, 7, and 10) was evaluated. Inhibition efficiency was assessed with conventional electrochemical techniques: open circuit potential, potentiodynamic polarization, and electrochemical impedance analysis. Glycerol reduced the corrosion rate of copper in NaCl solutions. The best inhibition effect (η≈83%) was produced in alkaline (pH 10) chloride media. This effect can be ascribed to increased viscosity and the presence of copper-glycerol complexes.

scholarly journals Electrochemical Study of Ni20Cr Coatings Applied by HVOF Process in ZnCl2-KCl at High Temperatures

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
J. Porcayo-Calderón ◽  
O. Sotelo-Mazón ◽  
M. Casales-Diaz ◽  
J. A. Ascencio-Gutierrez ◽  
V. M. Salinas-Bravo ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Electrochemical Techniques ◽  
Open Circuit ◽  
304 Stainless Steel ◽  
Experimental Conditions ◽  
Corrosive Media ◽  
Linear Polarization Resistance ◽  
Potentiodynamic Polarization Curves ◽  
Hvof Process ◽  
Oxygen Fuel

Corrosion behavior of Ni20Cr coatings deposited by HVOF (high velocity oxygen-fuel) process was evaluated in ZnCl2-KCl (1 : 1 mole ratio) molten salts. Electrochemical techniques employed were potentiodynamic polarization curves, open circuit potential, and linear polarization resistance (LPR) measurements. Experimental conditions included static air and temperatures of 350, 400, and 450°C. 304-type SS was evaluated in the same conditions as the Ni20Cr coatings and it was used as a reference material to assess the coatings corrosion resistance. Coatings were evaluated as-deposited and with a grinded surface finished condition. Results showed that Ni20Cr coatings have a better corrosion performance than 304-type SS. Analysis showed that Ni content of the coatings improved its corrosion resistance, and the low corrosion resistance of 304 stainless steel was attributed to the low stability of Fe and Cr and their oxides in the corrosive media used.

scholarly journals SYNTHESIS AND EVALUATION OF ETHYL (4-(N-(THIAZOL-2-YL) SULFAMOYL) PHENYL)CARBAMATE (TSPC) AS A CORROSION INHIBITOR FOR MILD STEEL IN 0.1M HCL

2016 ◽  
Vol 11 (2) ◽  
pp. 3441-3451 ◽  
Author(s):  
A. M. El-Shamy ◽  
M. F. Shehata ◽  
Samir T. Gaballah ◽  
Eman A. Elhefny
Keyword(s):  
Mild Steel ◽  
Corrosion Inhibitor ◽  
Room Temperature ◽  
Open Circuit Potential ◽  
Inhibition Efficiency ◽  
Electrochemical Techniques ◽  
Open Circuit ◽  
Free Energy Of Adsorption ◽  
Langmuir Adsorption ◽  
Gibb’S Free Energy

Laboratory synthesized ethyl (4-(N-(thiazol-2-yl)sulfamoyl)phenyl)carbamate (TSPC), characterized by 1H NMR spectroscopy, was evaluated as corrosion inhibitor of mild steel in 0.1M HCl using electrochemical techniques. Open circuit potential, potentiodynamic polarization and impedance spectroscopy were used to evaluate the inhibition efficiency of (TSPC) at various concentrations. The obtained electrochemical data indicated that (TSPC) acts as moderate corrosion inhibitor for mild steel in acidic media. It is found that the inhibition efficiency increases with the concentration of the inhibitor till 400ppm. The adsorption isotherm involving physisorption of (TSPC) at room temperature and the experimental data complied to the Langmuir adsorption isotherms and the negative values of the Gibb’s free energy of adsorption obtained suggested that inhibitor molecules have been spontaneously adsorbed onto the mild steel surface.

Comparison of Electrochemical Behavior of Cu-10Ni-10Zn Alloy and Cu in Aqueous Solutions

2015 ◽  
Vol 229 (3) ◽  
Author(s):  
Waheed A. Badawy ◽  
Mohamed M. El-Rabiei ◽  
Hashem M. Nady ◽  
Mohammed A. Samy
Keyword(s):  
Electrochemical Behavior ◽  
Electrochemical Impedance ◽  
Electrochemical Techniques ◽  
Pure Copper ◽  
Open Circuit ◽  
Chloride Ions ◽  
Alloy Surface ◽  
Metallic Surface ◽  
Copper Dissolution ◽  
Basic Solutions

AbstractThe electrochemical behavior of Cu-10Ni-10Zn alloy and Cu was investigated in acidic, neutral and basic solutions. The effect of chloride ions in neutral solutions was also studied. Conventional electrochemical techniques and electrochemical impedance spectroscopy were used. The corrosion rate of these materials in acidic solutions is relatively high compared to that in neutral or basic solutions. The open-circuit potential of the alloy is nearly the same as that of pure copper in the different media, indicating that the processes which occur on the alloy surface are mainly governed by copper dissolution. In chloride solutions the rate of Cu corrosion is remarkably high. In the alloy, the copper dissolution was suppressed by the presence of nickel and zinc, due to the formation of complex oxide layers. The impedance data were fitted to equivalent circuit models that explain the different electrochemical processes occurring at the electrode/electrolyte interface. SEM and EDAX have shown that the alloy surface is enriched with Ni. In neutral solutions the chloride ions are penetrating the metallic surface.

scholarly journals Effect of Cu Addition on the Electrochemical Corrosion Performance of Ni3Al in 1.0 M H2SO4

2015 ◽  
Vol 2015 ◽  
pp. 1-18 ◽  
Author(s):  
J. Porcayo-Calderon ◽  
R. A. Rodriguez-Diaz ◽  
E. Porcayo-Palafox ◽  
J. Colin ◽  
A. Molina-Ocampo ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Open Circuit Potential ◽  
Electrochemical Impedance ◽  
Electrochemical Corrosion ◽  
Open Circuit ◽  
Intermetallic Alloy ◽  
Intermetallic Alloys ◽  
Corrosion Performance ◽  
Linear Polarization Resistance ◽  
Electrochemical Corrosion Behavior

The effect of Cu addition on the electrochemical corrosion behavior of Ni3Al intermetallic alloy was investigated by potentiodynamic polarization, open-circuit potential, linear polarization resistance, and electrochemical impedance spectroscopy in 1.0 M H2SO4solution. Performance of the pure elements (Cu, Ni, and Al) was also evaluated. In general, Cu addition improved the corrosion resistance of Ni3Al. Electrochemical measurements show that corrosion resistance of Ni3Al-1Cu alloy is lower than that of other intermetallic alloys and pure elements (Ni, Cu, and Al) in 1.0 M H2SO4solution at 25°C. Surface analysis showed that the Ni3Al alloys are attacked mainly through the dendritic phases, and Cu addition suppresses the density of dendritic phases.

scholarly journals Pyrite Passivation by Triethylenetetramine: An Electrochemical Study

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Yun Liu ◽  
Zhi Dang ◽  
Yin Xu ◽  
Tianyuan Xu
Keyword(s):  
Cyclic Voltammetry ◽  
Potentiodynamic Polarization ◽  
Mixed Type ◽  
Open Circuit Potential ◽  
Inhibition Efficiency ◽  
Electrochemical Impedance ◽  
Open Circuit ◽  
Experimental Results ◽  
Coating Agent ◽  
Mixed Type Inhibitor

The potential of triethylenetetramine (TETA) to inhibit the oxidation of pyrite in H2SO4solution had been investigated by using the open-circuit potential (OCP), cyclic voltammetry (CV), potentiodynamic polarization, and electrochemical impedance (EIS), respectively. Experimental results indicate that TETA is an efficient coating agent in preventing the oxidation of pyrite and that the inhibition efficiency is more pronounced with the increase of TETA. The data from potentiodynamic polarization show that the inhibition efficiency (η%) increases from 42.08% to 80.98% with the concentration of TETA increasing from 1% to 5%. These results are consistent with the measurement of EIS (43.09% to 82.55%). The information obtained from potentiodynamic polarization also displays that the TETA is a kind of mixed type inhibitor.

scholarly journals Investigations of sintering temperature and cell viability of biocompatible nano Yttria stabilised zirconia coated on 316L SS for dental applications

2021 ◽  
Author(s):  
Mohandoss S ◽  
◽  
Srinivasan S.P. ◽  
Keyword(s):  
316L Stainless Steel ◽  
Open Circuit Potential ◽  
Electrochemical Impedance ◽  
Artificial Saliva ◽  
Electrochemical Techniques ◽  
Open Circuit ◽  
Stainless Steel 316L ◽  
Cyclic Potentiodynamic Polarization ◽  
Ysz Coating ◽  
Dental Applications

Development of biocompatible dental implants has become significant impact in dental industry. In the present work, we report for the development of biocompatible nano Yttria stabilised Zirconia (YSZ) coatings on 316L stainless steel (316L SS) obtained by EPD process. The optimized sample (nano YSZ coating on 316 obtained at applied potential of 70 V for 5 minutes) were sintered in air at 600, 800 and 900°C. The surface morphology and composition of the coatings were characterized by XRD and FE-SEM with EDAX. The electrochemical performance of the uncoated metal and nano YSZ coated 316L SS samples were evaluated in artificial saliva (AS) medium using electrochemical techniques such as Open Circuit Potential – time measurement (OCP), Electrochemical Impedance Spectroscopy (EIS) and Cyclic Potentiodynamic Polarization (CPP).

scholarly journals Evaluation of the Corrosion Inhibiting Capacity of Silica/Polypyrrole-Oxalate Nanocomposite in Epoxy Coatings

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Van T. H. Vu ◽  
Thanh T. M. Dinh ◽  
Nam T. Pham ◽  
Thom. T. Nguyen ◽  
Phuong T. Nguyen ◽  
...  
Keyword(s):  
Open Circuit Potential ◽  
Electrochemical Impedance ◽  
Electrochemical Techniques ◽  
Open Circuit ◽  
Epoxy Coating ◽  
Sodium Oxalate ◽  
Counter Anion ◽  
Epoxy Coatings ◽  
Protective Properties ◽  
Oxalate Anion

Silica/Polypyrrole nanocomposites (SiO2/PPy) incorporating oxalate as counter anion (SiO2/PPyOx) were chemically polymerized in the solution with the presence of pyrrole, silica, and sodium oxalate. Nanocomposites SiO2/PPyOx at different concentrations of oxalate anion were characterized with FTIR, XRD, EDX, TGA, and TEM. The corrosion protective properties for carbon steel of nanocomposites in epoxy coating were studied by electrochemical techniques including electrochemical impedance spectroscopy (EIS) and open circuit potential (OCP). FTIR results of nanocomposites show a slightly red-shift in terms of wavelength compared with the case of PPy and SiO2 spectra. It may be due to a better conjugation and interactions between PPy and SiO2 in nanocomposite structure. TEM image indicated that nanocomposites have spherical morphologies with diameters between 100 and 150 nm. The EIS results showed that |Z| modulus values of epoxy coatings containing SiO2/PPyOx composites reached about 109.7 Ω.cm2, always higher than that of epoxy coating. These results are also confirmed by OCP results. It proves that the presence of oxalate anion can enhance the resistance against corrosion and it has been shown that the content of counter anion strongly affects the anticorrosion ability.

scholarly journals Influence of the Chemical Composition in the Electrochemical Response of Permanent Magnets

2015 ◽  
Vol 2015 ◽  
pp. 1-16 ◽  
Author(s):  
S. Godavarthi ◽  
J. Porcayo-Calderon ◽  
E. Vazquez-Velez ◽  
M. Casales-Diaz ◽  
D. M. Ortega-Toledo ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Room Temperature ◽  
Permanent Magnets ◽  
Open Circuit Potential ◽  
Electrochemical Impedance ◽  
Open Circuit ◽  
Nacl Solution ◽  
Main Mode ◽  
Linear Polarization Resistance ◽  
Co Addition

The corrosion behavior of permanent magnets with different chemical composition was evaluated. Permanent magnets were tested in 3.5% NaCl solution at room temperature using electrochemical technics such as polarization curves, open-circuit potential, linear polarization resistance, and electrochemical impedance spectroscopy measurements. Results have shown that corrosion rate is affected by Nd, Pr, and Co content. Analysis by scanning electron microscopy has shown that pitting attack is the main mode of degradation of the magnets, while Co addition reduces it and Pr addition increases it.

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