scholarly journals Corrosion Behavior of Fe40Al Alloy with Additions of Ti, Ag, and Cr in Molten KCl +ZnCl2

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
R. Ademar ◽  
J. G. Gonzalez-Rodriguez ◽  
J. Uruchurtu ◽  
J. Porcayo-Calderon ◽  
V. M. Salinas-Bravo ◽  
...  
Keyword(s):  
Corrosion Rate ◽  
Corrosion Behavior ◽  
Electrochemical Impedance ◽  
Electrochemical Techniques ◽  
Intermetallic Alloy ◽  
Corrosion Performance ◽  
Linear Polarization Resistance ◽  
Potentiodynamic Polarization Curves ◽  
Eis Measurements ◽  
The Stability

The effect of 2.5 at.% Cr, Ti, and Ag on the corrosion behavior of Fe40Al intermetallic alloy in KCl-ZnCl2(1 : 1 M) at 670°C has been evaluated by using electrochemical techniques. Techniques included potentiodynamic polarization curves, linear polarization resistance (LPR), and electrochemical impedance spectroscopy (EIS) measurements. Results have shown that additions of both Cr and Ti were beneficial to the alloy, since they decreased its corrosion rate, whereas additions of Ag was detrimental, since its additions increased the corrosion rate, although the alloy was passivated by adding Ag or Cr. The best corrosion performance was obtained with the addition of Cr, whereas the highest corrosion rate was obtained by adding Ag. This is explained in terms of the stability of the corrosion products formed film.

Corrosion Behavior of Al-Sn-Bi Alloys in Ethylene Glycol-Water Mixtures

CORROSION ◽  
2012 ◽  
Vol 68 (5) ◽  
pp. 421-431
Author(s):  
J.L. Gama-Ferrer ◽  
J.G. Gonzalez-Rodriguez ◽  
I. Rosales ◽  
J. Uruchurtu
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Corrosion Rate ◽  
Ethylene Glycol ◽  
Corrosion Behavior ◽  
Potentiodynamic Polarization ◽  
Electrochemical Noise ◽  
Electrochemical Impedance ◽  
Electrochemical Techniques ◽  
Potentiodynamic Polarization Curves

A study of the effect of Sn (1, 2, 3.5, 4.5, and 5 wt%) and Bi (0.5, 1.5, 3, and 4%) on the corrosion behavior of Al in ethylene glycol (C2H6O2)-40% water mixtures at 20, 40, and 60°C has been carried out using electrochemical techniques. Techniques include potentiodynamic polarization curves, electrochemical impedance spectroscopy (EIS), and electrochemical noise (EN) measurements. The three techniques have shown that additions of either Sn or Bi contents increased the corrosion rate of pure Al in all cases, and that generally speaking, the corrosion rate increased by increasing the temperature except for the alloy containing 1% Sn + 4% Bi, which showed the lowest corrosion rate at 60°C. This was because of a galvanic effect from the presence of Sn and/or Bi particles on the surface alloy, which acted as local cathodes, leading to an acceleration of corrosion. Nyquist diagrams showed two semicircles at 20°C and only one at 40°C or 60°C for all the alloys, showing two different corrosion-controlling mechanisms. EN measurements showed evidence of a mixture of both localized and uniform types of corrosion for all Al-based alloys.

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.

Effects of Different Ions on the Corrosion Behavior of SM 80SS Tubing Steel in CO2/H2S Containing Aqueous Solution

2013 ◽  
Vol 734-737 ◽  
pp. 1367-1373
Author(s):  
Guan Fa Lin ◽  
Xun Chang Dong ◽  
Shi Dong Zhu ◽  
Zhen Quan Bai
Keyword(s):  
Aqueous Solution ◽  
Weight Loss ◽  
Corrosion Rate ◽  
Corrosion Behavior ◽  
Polarization Resistance ◽  
Electrochemical Impedance ◽  
Electrochemical Reaction ◽  
Initial Period ◽  
Activation Reaction ◽  
Linear Polarization Resistance

As an attempt to contribute to the understanding of the corrosion processes of anti-sulfur steel in CO2and H2S containing environment with different species, the corrosion behavior of SM 80SS tubing steel immersed in CO2and H2S containing solution was analyzed in this work. To determine the corrosion behavior of SM80SS steel, the linear polarization resistance (LPR) and electrochemical impedance spectroscopy (EIS) techniques were used, as well as weight loss test and surface analysis. The results showed that the presence of Cl-quickened the anodic dissolution processes and rapidly increased the corrosion rate of SM 80SS steel, and that the addition of Ca2+and Mg2+reduced corrosion rate. The corrosion processes of SM 80SS steel were controlled by the electrochemical reaction in the initial period and then converted to be controlled by electrochemical and activation reaction with increasing Cl-. Keywords: SM 80SS tubing steel; CO2/H2S corrosion; EIS; Chloride; Ca2++ Mg2+

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 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.

Electrochemical corrosion study of Pb-free solders

2006 ◽  
Vol 21 (1) ◽  
pp. 62-70 ◽  
Author(s):  
B.Y. Wu ◽  
Y.C. Chan ◽  
M.O. Alam ◽  
W. Jillek
Keyword(s):  
Acid Solution ◽  
Corrosion Behavior ◽  
Current Density ◽  
Corrosion Potential ◽  
Electrochemical Impedance ◽  
Electrochemical Corrosion ◽  
Corrosion Current ◽  
Corrosion Properties ◽  
Linear Polarization Resistance ◽  
Eis Measurements

This paper presents an investigation on the corrosion behavior of five solders by means of polarization and electrochemical impedance spectroscopy (EIS) measurements. The Sn–9Zn and Sn–8Zn–3Bi solder, in comparison with the Sn–3.5Ag–0.5Cu and Sn–3.5Ag–0.5Cu–9In solder, were tested in 3.5 wt% NaCl solution and 0.1 wt% adipic acid solution, respectively. The Sn–37Pb solder was for reference in this work. The polarization curves indicated that the Sn–9Zn and Sn–8Zn–3Bi solder showed the worst corrosion resistance both in the salt and acid solutions, in terms of corrosion-current density, corrosion potential, linear polarization resistance, and passivation-current density. Meanwhile, the Sn–3.5Ag–0.5Cu solder remained the best corrosion characteristics in both solutions. It was found that due to microstructure alteration, Bi additive to the Sn–9Zn solder improved the corrosion behavior in the salt solution, whereas decreased that in the acid solution. However, the additive of In degraded the Sn–3.5Ag–0.5Cu solder in both solutions. The EIS results agreed well with the noble sequence of the five solders subjected to the two solutions with polarization. The equivalent circuits were also determined. Nevertheless, the four Pb-free solders exhibited acceptable corrosion properties since there was not much difference of key corrosion parameters between them and the Sn–37Pb solder.

scholarly journals Cuminum cyminum Extracts as Eco-Friendly Corrosion Inhibitor for Mild Steel in Seawater

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
V. Sribharathy ◽  
Susai Rajendran
Keyword(s):  
Mild Steel ◽  
Potentiodynamic Polarization ◽  
Electrochemical Impedance ◽  
Cuminum Cyminum ◽  
Potentiodynamic Polarization Curves ◽  
Weight Loss Method ◽  
Loss Method ◽  
Eis Measurements ◽  
The Stability ◽  
Good Agreement

The inhibitive effect of Jeera (Cuminum cyminum) plant extracts on the corrosion of mild steel in an aqueous solution of seawater was investigated using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques. The stability of the inhibition efficiency of Jeera extracts was examined by weight-loss method. Potentiodynamic polarization curves indicated that the Jeera extract behaves as an anodic type inhibitor. EIS measurements showed that the dissolution process occurs under activation control. The corrosion rates of steel and the inhibition efficiencies of the extract obtained from impedance and polarization measurements were in good agreement. Inhibition was found to increase with an increasing concentration of the plant extract. The results obtained show that the Jeera extract could serve as an effective inhibitor for the corrosion of mild steel in seawater.

scholarly journals Corrosion Behavior of Mg-Al/TiC Composites in NaCl Solution

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
L. A. Falcon ◽  
E. Bedolla B. ◽  
J. Lemus ◽  
C. Leon ◽  
I. Rosales ◽  
...  
Keyword(s):  
Corrosion Rate ◽  
Corrosion Behavior ◽  
Electrochemical Impedance ◽  
Base Alloy ◽  
Electrochemical Techniques ◽  
Al Alloy ◽  
Nacl Solution ◽  
The Matrix ◽  
Diffusion Phenomena ◽  
Lower Corrosion Rate

The corrosion behavior of TiC particles reinforced Mg-Al alloy in 3.5% NaCl solution has been evaluated using electrochemical techniques. Tested alloys included an Mg-9Al (Mg AZ91E) alloy with and without 56 wt. % TiC particles. Electrochemical techniques included potentiodynamic polarization curves, linear polarization resistance, electrochemical noise, and electrochemical impedance spectroscopy measurements. All techniques showed that the composite exhibited a lower corrosion rate than the base alloy. Evidence of galvanic effects that increased the composite corrosion rate was found between the matrix and the TiC particles. Additionally, the tendency to suffer from pitting corrosion was higher for the base alloy than that for the composite. Electrochemical impedance results showed the importance of adsorption/diffusion phenomena in both materials.

Corrosion Behavior of MRI153M Magnesium Alloy in 3% NaCl Solution

2015 ◽  
Vol 227 ◽  
pp. 83-86
Author(s):  
Ohad Gaon ◽  
Barbara Kazanski ◽  
Alex Lugovskoy
Keyword(s):  
Magnesium Alloy ◽  
Corrosion Behavior ◽  
Electrochemical Impedance ◽  
Electrochemical Techniques ◽  
Electrochemical Methods ◽  
Gas Evolution ◽  
Linear Polarization Resistance ◽  
Corrosion Rates ◽  
Die Cast ◽  
Good Agreement

Corrosion behavior of high-pressure die cast creep resistant magnesium alloy MRI 153M in 3% NaCl aqueous solution was studied by several electrochemical and non-electrochemical techniques. The electrochemical techniques were Electrochemical Impedance Spectroscopy (EIS), Linear Polarization Resistance (LPR) and Tafel-slope Polarization. The non-electrochemical techniques were mass-loss and gas evolution measurements. Values of corrosion rates were calculated and the morphology of corroded surface studied. While corrosion rates calculated by both non-electrochemical methods are not consistent, those gained by the three electrochemical methods demonstrate consistency. In general, the rate of corrosion calculated by the gas evolution method is in a good agreement with the corrosion rate calculated from the electrochemical methods, which should be an indication of mixed chemical-electrochemical character of the process. SEM and light microscope observation of corroded specimens demonstrated the localized character of corrosion, at least at the initial stages.

scholarly journals Corrosion of Steel Rebars in Anoxic Environments. Part I: Electrochemical Measurements

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2491
Author(s):  
Elena Garcia ◽  
Julio Torres ◽  
Nuria Rebolledo ◽  
Raul Arrabal ◽  
Javier Sanchez
Keyword(s):  
Corrosion Rate ◽  
Electrochemical Impedance ◽  
Electrochemical Techniques ◽  
Chloride Content ◽  
Offshore Platforms ◽  
Anoxic Conditions ◽  
Current Limit ◽  
Anoxic Environments ◽  
Corrosion Of Steel ◽  
Steel Rebars

The number of reinforced concrete structures subject to anoxic conditions such as offshore platforms and geological storage facilities is growing steadily. This study explored the behaviour of embedded steel reinforcement corrosion under anoxic conditions in the presence of different chloride concentrations. Corrosion rate values were obtained by three electrochemical techniques: Linear polarization resistance, electrochemical impedance spectroscopy, and chronopotenciometry. The corrosion rate ceiling observed was 0.98 µA/cm2, irrespective of the chloride content in the concrete. By means of an Evans diagram, it was possible to estimate the value of the cathodic Tafel constant (bc) to be 180 mV dec−1, and the current limit yielded an ilim value of 0.98 µA/cm2. On the other hand, the corrosion potential would lie most likely in the −900 mVAg/AgCl to −1000 mVAg/AgCl range, whilst the bounds for the most probable corrosion rate were 0.61 µA/cm2 to 0.22 µA/cm2. The experiments conducted revealed clear evidence of corrosion-induced pitting that will be assessed in subsequent research.

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