Influence of pH on the Electrochemical Bahavior of 00Cr15Ni7Mo2Cu2 Supermartensitic Stainless Steel in 3.5% NaCl Solutions

2012 ◽  
Vol 581-582 ◽  
pp. 1058-1061
Author(s):  
Jia Qun Rui ◽  
Jun Li ◽  
Hu Dai Sun ◽  
Kun Yu Zhao ◽  
Zhi Dong Li ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Open Circuit Potential ◽  
Electrochemical Impedance ◽  
Open Circuit ◽  
Pitting Potential ◽  
Supermartensitic Stainless Steel ◽  
Pitting Corrosion Resistance ◽  
Polarization Technique ◽  
Current Densities ◽  
Influence Of Ph

This objective is to study the influence of pH on the electrochemical behavior of 00Cr15Ni7Mo2Cu2 supermartensitic stainless steel in 3.5% NaCl solutions using potentiondynamic polarization technique, open circuit potential tests and electrochemical impedance spectroscopy (EIS).The study reveals that the pitting potential (Eb) is higher, the passivation current densities (ip) is lower and the electrochemical impedance increases with the pH. The results indicate that this stainless steel offer good pitting corrosion resistance with the pH increasing in 3.5% NaCl solutions.

scholarly journals From Waste to Valuable Resource: Lignin as a Sustainable Anti-Corrosion Coating

Coatings ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 454 ◽  
Author(s):  
Arman Dastpak ◽  
Kirsi Yliniemi ◽  
Mariana de Oliveira Monteiro ◽  
Sarah Höhn ◽  
Sannakaisa Virtanen ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Open Circuit Potential ◽  
Electrochemical Impedance ◽  
Steel Corrosion ◽  
Linear Sweep Voltammetry ◽  
Corrosion Current ◽  
Polymer Coatings ◽  
Open Circuit ◽  
Linear Sweep ◽  
Cyclic Potentiodynamic Polarization

In this study, a waste of biorefinery—lignin—is investigated as an anticorrosion coating on stainless steel. Corrosion behavior of two lignin types (hardwood beech and softwood spruce) was studied by electrochemical measurements (linear sweep voltammetry, open circuit potential, potentiostatic polarization, cyclic potentiodynamic polarization, and electrochemical impedance measurements) during exposure to simulated body fluid (SBF) or phosphate buffer (PBS). Results from linear sweep voltammetry of lignin-coated samples, in particular, demonstrated a reduction in corrosion current density between 1 and 3 orders of magnitude cf. blank stainless steel. Furthermore, results from cross cut adhesion tests on lignin-coated samples demonstrated that the best possible adhesion (grade 0) of ISO 2409 standard was achieved for the investigated novel coatings. Such findings suggest that lignin materials could transform the field of organic coatings towards more sustainable alternatives by replacing non-renewable polymer coatings.

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.

Electrochemical Properties of Passive Film Formed on Supermartensitic Stainless Steel in a Chloride Medium

CORROSION ◽  
10.5006/3230 ◽  
2020 ◽  
Vol 76 (9) ◽  
pp. 884-890
Author(s):  
Renata B. Soares ◽  
Wagner R.C. Campos ◽  
Pedro L. Gastelois ◽  
Waldemar A.A. Macedo ◽  
Luís F.P. Dick ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Stainless Steel ◽  
Passive Film ◽  
Electrochemical Behavior ◽  
Photoelectron Spectroscopy ◽  
Oil And Gas ◽  
Electrochemical Impedance ◽  
Passive Layer ◽  
Open Circuit ◽  
Pitting Potential

The electrochemical behavior and the electronic properties of passive films formed on a super martensitic stainless steel (SMSS) used in oil and gas industries were investigated in aqueous 0.6 M and 2.1 M NaCl solutions with additions of sodium acetate and acetic acid (pH 4.5). Open-circuit potential transients, electrochemical impedance spectroscopy, cyclic voltammetry, and x-ray photoelectron spectroscopy were measured to characterize the passive film formed on SMSS. The electrochemical behavior of the steel in an aqueous solution of 0.6 M NaCl presented the highest pitting potential and the highest polarization resistance in relation to the NaCl/NaAc solution. The passive film of SMSS in an aqueous solution of NaCl presented a thickness of 18.40 nm, three times the thickness of the oxide film in NaCl/NaAc, and consisted of FeO, Cr2O3, MoO2, and spinels such as FeCr2O4 species that are a p-type semiconductor, but may also contain a small fraction of the Fe2O3 and MoO3 oxides. Additionally, it was shown that the passive layer after immersion in a saline solution also contains hydroxides such as FeOOH and Cr(OH)3.

scholarly journals Adsorption of Some Allylic Compounds on Polarized 304 Austenitic Stainless Steel Electrodes in H2SO4 Solutions

1996 ◽  
Vol 13 (1) ◽  
pp. 31-47
Author(s):  
Hamid A. Al-Megren ◽  
Abdulaziz A. Al-Suhybani
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Open Circuit Potential ◽  
Inhibition Efficiency ◽  
Open Circuit ◽  
Rate Of Reaction ◽  
304 Austenitic Stainless Steel ◽  
Current Densities ◽  
Anodic Reactions ◽  
Steel Electrodes

The adsorption of different compounds containing the allylic group on 304 austenitic stainless steel (304SS) in H2SO4 solutions was investigated under different conditions. These include the effect of H2SO4 (1–12 M), temperature (5–45°C), inhibitor concentration [inhibitor] (10−610−1 M) and the effect of Cl− on the inhibition efficiency (%Ef). The dependence of the open circuit potential (OCP) on time as well as on the above-mentioned conditions was also investigated. The current densities (cds) for the cathodic and anodic reactions were reported under the specified conditions. Such additives were found to greatly reduce the rate of reaction and for the weak inhibitors the extent of adsorption is enhanced in the presence of Cl−. In addition, the kinetic parameters and thermodynamic functions were evaluated using appropriate equations.

Experimental Study of Propagation Stage of Pitting Corrosion of 20Cr13 Steel

2008 ◽  
Vol 38 ◽  
pp. 238-247
Author(s):  
A.D. Davydov ◽  
V.S. Shaldaev
Keyword(s):  
Pitting Corrosion ◽  
Open Circuit Potential ◽  
Corrosion Potential ◽  
Ph Value ◽  
Open Circuit ◽  
Effect Of Temperature ◽  
Pitting Potential ◽  
Free Corrosion Potential ◽  
External Power Source ◽  
Corrosion Of Steel

The initiation and development of pitting corrosion of steel 20Cr13 in the NaCl solutions with various concentrations, temperatures, and pH values are studied under the potentiostatic conditions and at the free-corrosion potential. The pitting and repassivation potentials are determined using the method of cycling voltammetry. In spite of the fact that thus determined pitting potential is more positive than the corrosion potential (the open-circuit potential Eo.c.), the long-term experiments, which were performed at the free-corrosion potential, showed that pitting corrosion takes place without imposing a potential using an external power source. It is concluded that the probability of pitting corrosion of steel should be determined by comparing the corrosion potential (the open-circuit potential) with the repassivation potential Erp. Steel 20Cr13 is prone to the pitting corrosion, because Erp is more negative than Eo.c.. In the potentiostatic experiments, the variation of the depth and diameter of pits and their number with the time and the effect of temperature and electrode rotation on the pit propagation are studied. The results, which were obtained at the free-corrosion potential, are much less reproducible. In this case, in contrast to the potentiostatic conditions, the pit depth increased only slightly and the pit width increased to a larger extent. The effect of concentration, pH value, and temperature of NaCl solutions on the pit propagation is considered. It is concluded that the data on the development of pitting corrosion under the potentiostatic conditions can be hardly extended to the conditions of free corrosion potential.

Nano-Thick Amorphous Oxide Layer Produced by Plasma on Type 316L Stainless Steel for Improved Corrosion Resistance Under Plastic Deformation

CORROSION ◽  
10.5006/2674 ◽  
2018 ◽  
Vol 74 (9) ◽  
pp. 1011-1022 ◽  
Author(s):  
Megan Mahrokh Dorri ◽  
Stéphane Turgeon ◽  
Maxime Cloutier ◽  
Pascale Chevallier ◽  
Diego Mantovani
Keyword(s):  
Plastic Deformation ◽  
Stainless Steel ◽  
Oxide Layer ◽  
Electrochemical Impedance ◽  
Open Circuit ◽  
Localized Corrosion ◽  
Native Oxide ◽  
Native Oxide Layer ◽  
Amorphous Oxide ◽  
Amorphous Oxide Layer

Localized corrosion constitutes a major concern in medical devices made of stainless steel. The conventional approach to circumvent such a problem is to convert the surface polycrystalline microstructure of the native oxide layer to an amorphous oxide layer, a few micrometers thick. This process cannot, however, be used for devices such as stents that undergo plastic deformation during their implantation, especially those used in vascular surgery for the treatment of cardiac, neurological, and peripheral vessels. This work explores the feasibility of producing a nano-thick plastic-deformation resistant amorphous oxide layer by plasma-based surface modifications. By varying the plasma process parameters, oxide layers with different features were produced and their properties were investigated before and after clinically-relevant plastic deformation. These properties and the related corrosion mechanisms were mainly evaluated using the electrochemical methods of open-circuit potential, cyclic potentiodynamic polarization, and electrochemical impedance spectroscopy. Results showed that, under optimal conditions, the resistance to corrosion and to the permeation of ions in a phosphate buffered saline, even after deformation, was significantly enhanced.

scholarly journals The Effect of the Action of Impurities Present in Methanol as a Basis for Automobile Fuel and Their Impact on the Environment

2020 ◽  
Vol 70 (12) ◽  
pp. 4260-4265
Keyword(s):  
Air Pollution ◽  
Aluminum Alloy ◽  
Acid Chloride ◽  
Considerable Increase ◽  
Open Circuit Potential ◽  
Corrosion Potential ◽  
Open Circuit ◽  
Sulfur Oxides ◽  
Pitting Potential ◽  
Hydroxyl Ion

Corrosion of the tank made of aluminum alloy AlMg2,7Mn (5454) has been studied by electrochemical methods in methanolic solution containing different concentrations of acid, chloride, sulphate and water as impurities. In all these cases, the alloy exhibited a sponge passivity. Adding a 1mM solution in fuel leads to a considerable increase in corrosion potential, a 1 mM chlorine solution decreases the pitting potential, and a 1 mM solution of sulfate concentrations does not show any change. In the first phase, due to the hydroxyl ion that surrounds the aluminum, the present water leads to a decrease in the pitting potential.At the same time, the combustion of fuel remains the biggest source of air pollution. The air is polluted by impurities (acids, chlorides, sulphates and water) present in fuels, smoke (incomplete combustion) or nitrogen and sulfur oxides, so it is required to keep them within the limits set by the rules in force. Keywords: aluminium alloy, pitting potential, impurities, polarization curves, open circuit potential

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.

Influence of Sigma Phase Precipitation on Pitting Corrosion of 2507 Super-Duplex Stainless Steel

2010 ◽  
Vol 658 ◽  
pp. 380-383 ◽  
Author(s):  
Ying Han ◽  
De Ning Zou ◽  
Wei Zhang ◽  
Jun Hui Yu ◽  
Yuan Yuan Qiao
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Ambient Temperature ◽  
Duplex Stainless Steel ◽  
Pitting Corrosion ◽  
Super Duplex Stainless Steel ◽  
Phase Precipitation ◽  
Pitting Potential ◽  
Σ Phase ◽  
Pitting Corrosion Resistance

Specimens of 2507 super-duplex stainless steel aging at 850°C for 5 min, 15 min and 60 min were investigated to evaluate the pitting corrosion resistance in 3.5% NaCl solution at 30°C and 50°C. The results are correlated with the microstructures obtained with different aging time. The precipitation of σ phase remarkably decreases the pitting corrosion resistance of the steel and the specimen aged for 60 min presents the lowest pitting potential at both 30°C and 50°C. With increasing the ambient temperature from 30°C to 50°C, the pitting potential exhibits a reduction tendency, while this tendency is less obviously in enhancing the ambient temperature than in extending the isothermal aging duration from 5 to 60 min. SEM analysis shows that the surrounding regions of σ phase are the preferable sites for the formation of corrosion pits which grew up subsequently. This may be attributed to the lower content of corrosion resistance elements in these regions formatted with σ phase precipitation.

Sign in / Sign up

Export Citation Format

Share Document