scholarly journals An Electrochemical Study to Evaluate the Effect of Calcium Nitrite Inhibitor to Mitigate the Corrosion of Reinforcement in Sodium Chloride Contaminated Ca(OH)2Solution

2017 ◽  
Vol 2017 ◽  
pp. 1-14 ◽  
Author(s):  
Hwa-Sung Ryu ◽  
Jitendra Kumar Singh ◽  
Han-Seung Lee ◽  
Won-Jun Park
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Sodium Chloride ◽  
Anodic Polarization ◽  
Open Circuit Potential ◽  
Electrochemical Impedance ◽  
Open Circuit ◽  
Nacl Solution ◽  
Steel Rebar ◽  
Calcium Nitrite ◽  
Corrosion Of Steel

The effect of calcium nitrite (Ca(NO2)2) was assessed by electrochemical means such as open circuit potential (OCP), electrochemical impedance spectroscopy (EIS), and potentiodynamic studies in saturated Ca(OH)2solution contaminated with 0.99 and 7.91 g/L NaCl. The preliminary results of OCP showed that the potential is shifted towards positive (noble) side as content of inhibitor increased. The EIS results indicate that Ca(NO2)2works effectively in reduction and initiation of corrosion of steel rebar in NaCl contaminated Ca(OH)2solution. Potentiodynamic studies revealed the pitting tendency of steel rebar exposed in 0.99 g/L NaCl at [Cl−/NO2-] = 1.2 attributed to low conductivity of passive film which causes interference for Cl−ions attack during anodic polarization. The 85.75% efficiency is found in 0.99 g/L at [Cl−/NO2-] = 1.2. The Ca(NO2)2inhibitor transformed the unstable iron oxides/hydroxides into stable and protective oxides/hydroxides due to its strong oxidizing nature. Therefore, this inhibitor is sufficiently and significantly reducing the corrosion of steel rebar at even its low concentration with 0.99 and 7.91 g/L NaCl solution.

scholarly journals Χαρακτηρισμός πολυμερικών επιστρώσεων με νανοπερίεκτες σε μέταλλα για την προστασία τους από διάβρωση σε θαλάσσιο περιβάλλον

2012 ◽  
Author(s):  
Ανδρόνικος Μπαλάσκας
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Open Circuit Potential ◽  
Electrochemical Impedance ◽  
Open Circuit ◽  
X Ray Diffraction ◽  
X Ray ◽  
Organically Modified Silicates ◽  
Organically Modified ◽  
Ft Ir ◽  
Scanningelectron Microscopy

Υβριδικές επιστρώσεις οργανικά τροποποιημένων πυριτικών ενώσεων και εποξειδικώνρητινών (Organically Modified Silicates, ORMOSILs – epoxy) εφαρμόστηκαν στο κράμααργιλίου 2024-Τ3 και σε γαλβανισμένο χάλυβα σε υψηλές θερμοκρασίες (Hot Dip GalvanizedSteel, HDGS) προκειμένου αυτές να προστατεύσουν τα υποστρώματα από τη διάβρωση. Για τηνβελτίωση της αντοχής των επιστρώσεων στην διάβρωση ενσωματώθηκαν στην πολυμερικήμήτρα νανοπεριέκτες από μολυβδαινικό δημήτριο (CeMo) και οξείδιο του τιτανίου (TiO2),καθώς και pH-ευαίσθητα οργανικά νανοδοχεία πληρωμένα με τους αναστολείς διάβρωσης 2-μερκαπτοβενζοθειαζόλιο, 8-υδροξυκινολίνη, 1H-βενζοτριαζολο-4-σουλφονικό οξύ καιεξαφλουοροτιτανικό οξύ.Οι υβριδικές επιστρώσεις εφαρμόστηκαν στο υπόστρωμα με τη διαδικασία εμβάπτισης.Η μορφολογία των επιστρώσεων εξετάστηκε με ηλεκτρονική μικροσκοπία σάρωσης (ScanningElectron Microscopy (SEM)). Η σύνθεση και η δομή τους μελετήθηκε με υπέρυθρηΦασματοσκοπία μετασχηματισμού Fourier (FT-IR) και με μικροανάλυση με φθορισμομετρίαακτίνων Χ (Energy Dispersive X-Ray Analysis (EDX)). H ηλεκτροχημική φασματοσκοπίασύνθετης αντίστασης (Electrochemical Impedance Spectroscopy, EIS), η dc-πόλωση (dcpolarization)και η μέτριση ανοικτού δυναμικού (open circuit potential, OCP) χρησιμοποιήθηκανγια την αξιολόγηση των αντι-διαβρωτικών ιδιοτήτων των επιστρώσεων. Τα αποτελέσματαέδειξαν ότι οι επιστρώσεις με πληρωμένα νανοδοχεία έχουν αυξημένες αντιδιαβρωτικέςιδιότητες συγκριτικά με τις υπόλοιπες επιστρώσεις εμφανίζοντας και ιδιότητες αυτο-θεραπείας.Τέλος, συντέθηκαν νανόσφαιρες οξειδίου του χαλκού (Cu2O), οι οποίεςχαρακτηρίστηκαν με SEM, ηλεκτρονική μικροσκοπία διερχόμενης δέσμης (ΤransmissionΕlectron Μicroscopy (TEM)) και περίθλαση ακτίνων Χ (X ray Diffraction (XRD)). Οινανόσφαιρες στη συνέχεια πληρώθηκαν με ουσίες που δρουν ως βιοκτόνα και ενσωματώθηκανσε βαφές εμπορίου και σε επιστρώσεις βασισμένες σε εποξειδικές ενώσεις και μελετήθηκε ηδράση τους ως αντιαποθετικά αντιδραστήρια. Τα αποτελέσματα έδειξαν ότι οι επιστρώσεις μεπληρωμένες νανόσφαιρες Cu2O είχαν μεγαλύτερη αποτελεσματικότητα σε σύγκριση με τιςβαφές εμπορίου με βιοκτόνα μετά από έκθεση σε θαλάσσιο περιβάλλον.

A Research on the Protective Performance of Green Organic Composite Coating on Vehicle Equipment

2013 ◽  
Vol 325-326 ◽  
pp. 79-82
Author(s):  
An Tao Xu ◽  
Bing Luo ◽  
Fan Zhang ◽  
Fu Jin ◽  
Yang Yang Liu
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Composite Coating ◽  
Research Method ◽  
Open Circuit Potential ◽  
Electrochemical Impedance ◽  
Open Circuit ◽  
Simulation Research ◽  
Damage Level ◽  
Damage Simulation ◽  
Protective Performance

By adopting coating damage simulation research method with open circuit potential and electrochemical impedance spectroscopy, the influence of different damage levels of green organic composite coating to its protective performance has been studied. The research found that the variation of open circuit potential partly reflected the damage level of the coating. When K is less than or equal to 0.04, the coating still has favorable protective performance, while K is higher than 16, the protective performance of the coating is basically unavailable, but when K falls in between, the protective performance of the coating is fair good.

Study on Corrosion Process of Al-Mg Coatings Based on Electrochemical Impedance Spectroscopy

2017 ◽  
Vol 744 ◽  
pp. 380-384
Author(s):  
Hui Tong ◽  
Wen Li Han ◽  
Zhong Ping Xu ◽  
Yan Jun Zhang ◽  
Zhu Lin ◽  
...  
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Electrochemical Impedance ◽  
Open Circuit ◽  
Corrosion Process ◽  
Corrosion Products ◽  
Passive Films ◽  
Nacl Solution ◽  
Electrochemical Testing ◽  
Immersion Corrosion

Electrochemical impedance spectroscopy (EIS) is a technology of nondestructive electrochemical testing. In this paper, EIS is applied to study the corrosion processes of Al-Mg coatings. In the initial 24 h of immersion in 3.5% NaCl solution, passive films of Al-Mg coatings dissolve quickly. As time passed, corrosion products increase on surface gradually, which can inhibit corrosion. After 480h of immersion, corrosion products fully cover on Al-Mg coatings’ surface. The EIS of different corrosion processes are fitted by three equivalent circuits corresponding to the three corrosion processes. In the test of open circuit potentials (OCP), OCP is instable in the initial 24 h of immersion. As immersion time goes by, OCP tends to stabilization at about -0.90 V. Measurements of scanning electron microscope (SEM) confirm the conclusions of electrochemical measurements.

Effect of Different Dopants in Films TEOS/MPTS Used to Protect the Carbon Steel

2014 ◽  
Vol 805 ◽  
pp. 167-171 ◽  
Author(s):  
F.S. Silva ◽  
P.H. Suegama ◽  
W.P. Silva ◽  
A.W. Rinaldi ◽  
N.L.C. Domingues ◽  
...  
Keyword(s):  
Carbon Steel ◽  
Open Circuit Potential ◽  
Hybrid Film ◽  
Electrochemical Impedance ◽  
Open Circuit ◽  
The Other ◽  
Nacl Solution ◽  
Hybrid Films ◽  
Impedance Measurements ◽  
Current Densities

Schiff bases m-toluene N-Salicylideneaniline (m-TOL), (B) m-nitro-N- Salicylideneaniline (m-NTR) and (C) m-methoxy-N-salicylideneaniline (m-MTX) and cerium ions were studied added to 3.5 wt.% NaCl solution and added to the hybrid film based tetraethoxysilane (TEOS) e 3-methacryloxypropyltrimethoxysilane (MPTS). The polarization measurements showed lower current densities for the steel in NaCl with m-MTX, indicating that the m-MTX may be acting as an inhibitor. The hybrid films were doped with the m-MTX, Ce (III) or Ce (IV). Electrochemical measurements of open circuit potential (EOC), polarization curves and electrochemical impedance spectroscopy (EIS), were used to evaluate the corrosion behavior of the hybrid films. According Electrochemical Impedance measurements, all hybrid films, provided protection to the carbon steel. The films doped with Ce (IV), provided greater protection than the other, which indicates that this is the most suitable dopant for use in films.

Corrosion Behavior of Alloys for Hot Dipping

2013 ◽  
Vol 634-638 ◽  
pp. 2935-2938
Author(s):  
You Bin Wang ◽  
Jian Min Zeng
Keyword(s):  
Open Circuit Potential ◽  
Electrochemical Impedance ◽  
Open Circuit ◽  
Corrosion Property ◽  
Nacl Solution ◽  
Low Frequencies ◽  
High Impedance ◽  
Relaxation Time Constants ◽  
Phase Angles ◽  
Good Agreement

The corrosion property of three currently used hot dipped alloys (Al-8Si, Zn-0.6Ni and 55Al-Zn-Si) immersed in 3.5% NaCl solution were studied by analyzing the open circuit potential variation with time and electrochemical impedance spectroscopy (EIS) tests. The open circuit potential of the Al-8Si alloy is 100mV higher than the potential of Zn-0.6Ni and 55Al-Zn-Si, and the potential of Zn-0.6Ni is approach to the 55Al-Zn-Si alloy. The phase angles of the Al-8Si, 55Al-Zn-Si and Zn-0.6Ni are close to -80°,-70°,-60°, and the high impedance values at low frequencies are 105,104,103 Ω cm2, respectively. The EIS spectra of the alloys indicated two relaxation time constants. An “equivalent circuit” with the circuit elements representing the electrochemical properties was proposed to simulate the EIS spectra, and the simulated dates were in a good agreement with the experiment dates. The polarization resistance (Rp) of Al-8Si, 55Al-Zn-Si and Zn-0.6Ni are 18000, 2010, 251 Ω•cm-2, respectively. The results showed that the corrosion property of Al-8Si is well than the other alloys in the test solution.

scholarly journals The Estimation of Corrosion Behavior of NiTi and NiTiNb Alloys Using Dynamic Electrochemical Impedance Spectroscopy

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Georgiana Bolat ◽  
Daniel Mareci ◽  
Sorin Iacoban ◽  
Nicanor Cimpoesu ◽  
Corneliu Munteanu
Keyword(s):  
Open Circuit Potential ◽  
Electrochemical Impedance ◽  
Layer Structure ◽  
Passive Layer ◽  
Open Circuit ◽  
Impedance Spectra ◽  
Nacl Solution ◽  
Polarization Test ◽  
Dynamic Electrochemical Impedance Spectroscopy ◽  
Electrochemical Impedance Spectroscopic

Linear anodic potentiodynamic polarization and dynamic electrochemical impedance spectroscopic (DEIS) measurements were carried out for NiTi and NiTiNb alloys in physiological 0.9 wt% NaCl solution in order to assess their corrosion resistance. DEIS measurements were performed from open circuit potential to dissolution potential. It was shown that the impedance measurements in potentiodynamic conditions allow simultaneous investigation of changes in passive layer structure. The impedance spectra of various potential regions were fitted and also discussed. The surface morphology of the alloys after linear anodic polarization test was studied using scanning electron microscopy (SEM) technique.

Effect of the Fe/Cu Relationship Corrosion and low Alloying Elements on Corrosion Behavior of Cast Aluminum Parts

2016 ◽  
Vol 1815 ◽  
Author(s):  
C. Rodríguez-Rivera ◽  
J.A. García-Hinojosa ◽  
F.J. Rodríguez-Gómez
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Aluminum Alloys ◽  
Impedance Spectroscopy ◽  
Corrosion Rate ◽  
Open Circuit Potential ◽  
Electrochemical Impedance ◽  
Open Circuit ◽  
Localized Corrosion ◽  
Corrosion Mechanism ◽  
Corrosion Morphology

ABSTRACTThe aim of this study is to compare the corrosion rate of aluminum alloys for ornamental pieces. Three Fe/Cu relationships were tested in order to improve hardness and brightness in aluminum pieces since these alloys are used in the making of ornamental pieces. The variation on Fe/Cu content could result in modification on corrosion rate, since a metallographic characterization must be carried out identifying the presence of intermetallic phases. The presence of these elements could result in increasing corrosion rate, or even in modification of corrosion morphology, so localized corrosion could be expected.The assessment of corrosion rate was carried out in saline media, since chlorides are ions that promote localized corrosion. Electrochemical techniques (polarization curves and Tafel plots) were used in order to evaluate the attack in aluminum pieces; electrochemical impedance spectroscopy was also employed with voltage amplitude of 10 mV rms, and a frequency range from 10,000 Hz to 0.01 Hz. A typical three electrodes cell was used, exposing an area of one cm2. Before polarization, open circuit potential was monitored for an hour looking for a steady state. All conditions were tested for triplicate.The behavior of open circuit potential vs. time, and polarization curves was analyzed; a corrosion mechanism is proposed according to the electrochemical control. Polarization rate was calculated by using Tafel plots and, an electrochemical impedance spectroscopy analysis by using equivalent electric circuits is shown. Electrochemical impedance will yield information about corrosion morphology that is backed with microscopic inspection.The objective of this study is to compare the corrosion rate of aluminum alloys for ornamental pieces in order to determine the effect of the relationship Fe/Cu on the corrosion mechanism in aluminum parts for ornamental pieces.

Obtaining and Characterization of Zirconium and Cerium Coatings

2016 ◽  
Vol 869 ◽  
pp. 711-715
Author(s):  
Larissa Oliveira Berbel ◽  
Larissa Aparecida Corrêa Matos ◽  
Paulo Vitor Sochodolak ◽  
Claudia Schlindwein ◽  
Paulo Rogério Pinto Rodrigues ◽  
...  
Keyword(s):  
Metal Surfaces ◽  
Anodic Polarization ◽  
Open Circuit Potential ◽  
Electrochemical Impedance ◽  
Pechini Method ◽  
Open Circuit ◽  
Good Resistance ◽  
Potentiodynamic Anodic Polarization ◽  
Scanning Electron

Some metals prior to receiving a layer of paint should be submitted to a treatment of metal surface, since they are subjected to corrosion. This work aims the obtaining and characterization of a coating based on ceramics of cerium and / or zirconium for metal surfaces treatment. The ceramics were obtained by immersing the aluminum alloy 3003 and the carbon steel (SAE 1010) in the polymeric resin of citric acid and ethylene glycol according to the Pechini method. The characterization of the samples was performed using the following techniques: scanning electron microscopy (SEM), open circuit potential (OCP), electrochemical impedance spectroscopy (EIS) and Potentiodynamic Anodic Polarization (PAP). It was confirmed that the coatings of cerium and / or zirconium presented themselves as promise in the treatment of metal surfaces, because both showed good resistance, protecting the metal from corrosion.

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.

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.

Sign in / Sign up

Export Citation Format

Share Document