scholarly journals Effect of Phosphate-Based Inhibitor on Corrosion Kinetics and Mechanism for Formation of Passive Film onto the Steel Rebar in Chloride-Containing Pore Solution

Materials ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 3642
Author(s):  
Soumen Mandal ◽  
Jitendra Kumar Singh ◽  
Dong-Eun Lee ◽  
Taejoon Park
Keyword(s):  
Oxide Film ◽  
Photoelectron Spectroscopy ◽  
Electrochemical Impedance ◽  
Ammonium Phosphate ◽  
Iron Phosphate ◽  
Nacl Solution ◽  
Steel Rebar ◽  
Corrosion Kinetics ◽  
Corrosion Of Steel ◽  
Passive Oxide Film

In the present study, different contents, i.e., 1–3% of 0.5 M ammonium phosphate mono basic (APMB), were used as corrosion inhibitor to reduce the corrosion of steel rebar. Electrochemical impedance spectroscopy (EIS) results showed that up to 24 h of exposure, polarization resistance (Rp) and passive/oxide film resistance (Ro) gradually decreased in simulated concrete pore (SCP) + 3.5 wt.% NaCl solution owing to the reduction in pH of the solution. The steel rebar exposed in 2% inhibitor containing SCP + 3.5 wt.% NaCl solution exhibited 90% inhibition efficiency after 1 h of exposure. X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy confirmed the formation of thermodynamically very stable and sparingly soluble goethite (α-FeOOH), maghemite (γ-Fe2O3), and iron phosphate (FePO4) as passive/oxide film onto the steel rebar surface exposed to 2% inhibitor containing SCP + 3.5 wt.% NaCl solution.

scholarly journals Ammonium Phosphate as Inhibitor to Mitigate the Corrosion of Steel Rebar in Chloride Contaminated Concrete Pore Solution

Molecules ◽  
2020 ◽  
Vol 25 (17) ◽  
pp. 3785
Author(s):  
Soumen Mandal ◽  
Jitendra Kumar Singh ◽  
Dong-Eun Lee ◽  
Taejoon Park
Keyword(s):  
Passive Film ◽  
Ammonium Phosphate ◽  
Corrosion Current ◽  
Iron Phosphate ◽  
Nacl Solution ◽  
Steel Rebar ◽  
Prolonged Duration ◽  
Corrosion Inhibition Efficiency ◽  
Corrosion Of Steel ◽  
Steel Rebars

In the present study, different amounts, i.e., 1–3 v/v% of 1 M ammonium phosphate monobasic, were used as an eco-friendly corrosion inhibitor to mitigate the corrosion of steel rebar exposed to simulated concrete pore (SCP) + 3.5 wt% NaCl solution at a prolonged duration. Potentiodynamic polarization results show that as the amount of inhibitor is increased, the corrosion resistance of steel rebar is increased. The steel rebar exposed to 3% inhibitor-containing SCP + 3.5 wt% NaCl solution exhibited nobler corrosion potential (Ecorr), the lowest corrosion current density (icorr), and 97.62% corrosion inhibition efficiency after 1 h of exposure. The steel rebars exposed to 3% inhibitor-containing SCP + 3.5 wt% NaCl solution revealed higher polarization resistance (Rp) and film resistance (Ro) with exposure periods compared to other samples owing to the formation of passive film. The scanning electron microscopy (SEM) of steel rebar exposed to 3% inhibitor-containing SCP + 3.5 wt% NaCl solution showed homogenous and uniform dendritic passive film which covers all over the surface, whereas, bare, i.e., SCP + 3.5 wt% NaCl solution exposed samples exhibited pitting and irregular morphology. Raman spectroscopy results confirm the formation of goethite (α-FeOOH), maghemite (γ-Fe2O3), and iron phosphate (FePO4) as a passive film onto the steel rebar surface exposed to 3% inhibitor-containing SCP + 3.5 wt% NaCl solution. These phases are responsible for the corrosion mitigation of steel rebar which are very protective, adherent, and sparingly soluble.

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.

Effect of the sample form on the corrosion behavior of steels for concrete in 3% NaCl medium

2021 ◽  
Vol 109 (2) ◽  
pp. 201
Author(s):  
Laidi Babouri ◽  
Cheikh Mokrani ◽  
Yassine El Mendili
Keyword(s):  
Electron Microscopy ◽  
Linear Polarization ◽  
Saline Solution ◽  
Electrochemical Impedance ◽  
Nacl Solution ◽  
Tafel Polarization ◽  
Eds Analysis ◽  
Corrosion Of Steel ◽  
Surface Morphologies ◽  
Scanning Electron

Corrosion of steel constitutes a major preoccupation in the field of civil engineering and the building sector. In this paper, we investigated the electrochemical behavior of two steel specimens with different forms (latched steel and smooth steel) in a 3 wt.% NaCl solution. For this purpose, we studied the steel samples by linear polarization, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). The surface morphologies of the substrates were examined by scanning electron microscopy coupled with energy diffraction spectroscopy (SEM/EDS). Results of linear polarization, Tafel polarization curves and EIS show that latched steel (LS) is more susceptible to corrosion than smooth steel (SS) in saline solution. Gravimetric and SEM/EDS analysis after 10 days of immersion confirmed the results obtained by electrochemical methods. All of our results are in agreement and demonstrate that the sample form plays a key role in corrosion resistance.

scholarly journals Study on Corrosion Behavior of Ultrafine-Grained Ti-6Al-7Nb Fabricated by Equal Channel Angular Pressing

Metals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 950 ◽  
Author(s):  
Zequn Yu ◽  
Yuecheng Dong ◽  
Xin Li ◽  
Jingzhe Niu ◽  
Igor Alexandrov ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Oxide Film ◽  
Equal Channel Angular Pressing ◽  
Corrosion Behavior ◽  
Photoelectron Spectroscopy ◽  
Electrochemical Impedance ◽  
Electrochemical Measurement ◽  
Coarse Grained ◽  
Angular Pressing ◽  
Ultrafine Grained

The aim of this study was to investigate the corrosion resistance of ultrafine-grained (UFG) Ti-6Al-7Nb fabricated by equal channel angular pressing (ECAP) and coarse-grained (CG) Ti- 6Al- 7Nb. The microstructure of each specimen was investigated by the electron backscattered diffraction (EBSD) method. The corrosion behavior of each specimen was determined by electrochemical measurement in Ringer’s solution. The surface corroded morphologies and oxide film formed on Ti-6Al-7Nb alloy after electrochemical measurement were investigated by scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS). EBSD investigation shows that the grain size of UFG Ti-6Al-7Nb decreased to ~0.4 µm, accompanied by low angle grain boundaries (LAGBs) accounting for 39%. Potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) results indicated that UFG Ti-6Al-7Nb alloy possessed a better corrosion resistance. The surface corroded morphologies revealed many small and shallow corrosion pits, which can be attributed to the good compactness of the oxide film and a rapid self- repairing ability of the UFG Ti-6Al-7Nb alloy.

Introduction of Li+ Ions into Anodic Film by Hydrotalcite Precursor and Electrochemical Behavior

2006 ◽  
Vol 11-12 ◽  
pp. 509-512 ◽  
Author(s):  
Hao Ye ◽  
Yu Zuo ◽  
Jin Ping Xiong ◽  
Jing Mao Zhao
Keyword(s):  
Photoelectron Spectroscopy ◽  
Electrochemical Impedance ◽  
Lithium Ion ◽  
Anodic Film ◽  
Nacl Solution ◽  
X Ray Diffraction ◽  
Precursor Method ◽  
X Ray ◽  
Al Composite ◽  
High Purity Aluminum

Lithium ion was introduced into high purity aluminum (99.999%) by hydrotalcite precursor method, and Li/Al composite anodic film was obtained by anodizing. The methods of X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to investigate the properties of the anodic film. The electrochemistry behaviors of composite anodic film were studied by means of potentiodynamic method and electrochemical impedance spectroscopy (EIS). The results showed that the composite anodic film was produced by hydrotalcite precursor method and which is amorphous to X-ray diffraction. The passivation current density of the anodic film in NaCl solution (1mol/L, pH=3, 7, 11) decreased obviously, while impedance value increased sharply. Corrosion resistance of the composite anodic film in NaCl solution was improved by the introduction of Li+ ion.

scholarly journals Effect of immersion time at the stainless steel 304L/NaCl (0.01 M) interface

2019 ◽  
Vol 9 (2) ◽  
pp. 99-111
Author(s):  
Wejdene Mastouri ◽  
Luc Pichon ◽  
Serguei Martemianov ◽  
Thierry Paillat ◽  
Anthony Thomas
Keyword(s):  
Stainless Steel ◽  
Photoelectron Spectroscopy ◽  
Immersion Time ◽  
Surface Composition ◽  
Electrochemical Impedance ◽  
Open Circuit ◽  
Nacl Solution ◽  
Aisi 304L ◽  
X Ray ◽  
Steel Aisi

Stainless steels are broadly used thanks to their specific physical properties such as their high corrosion resistance in poorly aggressive solutions. However, only few studies have been reported in the literature concerning their electrochemical behavior in low concentration electrolytes medium. Accordingly, the present work aims to study the immersion time influence on the solid-liquid interface properties of the austenitic stainless steel AISI 304L, immersed in a low-concentrated (0.01 M) sodium chloride (NaCl) solution. The electroche­mical behavior of the interface was evaluated by electrochemical impedance spectroscopy (EIS) and open circuit potential (OCP) monitoring. The morphological features and the modification of the surface composition were evaluated by Optic Microscopy, Scanning Electron Microscopy, Energy Dispersive X-ray Spectrometry, Atomic Force Microscopy, White Light Interferometry and X-ray Photoelectron Spectroscopy. It was determined by OCP measurement that the characteristic time of the interface stabilization is very long (several months). After an immersion of 2 months in NaCl solution, a second time constant on impedance phase diagram appears. Surface characterizations reveal a significant modifi­cation of the morphology and chemistry of the AISI 304L surface that can be linked to OCP/EIS observations. It can be noticed that the repeatability deviation of the EIS method was about 1 % while its reproducibility deviation was estimated to 35 %.

scholarly journals Performance of corrosion protection of carbon steel with cerium modified phosphate–permanganate coatings and a layer of silane doped with cerium

Chemija ◽  
2019 ◽  
Vol 30 (3) ◽  
Author(s):  
O. Girčienė ◽  
L. Gudavičiūtė ◽  
A. Martušienė ◽  
V. Jasulaitienė ◽  
A. Selskienė ◽  
...  
Keyword(s):  
Carbon Steel ◽  
Photoelectron Spectroscopy ◽  
Electrochemical Impedance ◽  
Corrosion Behaviour ◽  
Low Frequency ◽  
Cerium Nitrate ◽  
Self Healing ◽  
Nacl Solution ◽  
Composition And Structure ◽  
Eis Measurements

This work was aimed to evaluate the effect of bis-[triethoxysilylpropyl] tetrasulfide (BTESPT) doped with cerium nitrate, as a corrosion inhibitor, on improved corrosion resistance of samples of carbon steel with a phosphate–permanganate layer in a 0.5 M NaCl solution. The main goal of the present work was to compare self-healing capacities of cerium conversion coatings and cerium as an additive inhibitor to silane. The composition and structure of the investigated samples were characterized by scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS) techniques, while the corrosion behaviour was investigated applying voltametric and electrochemical impedance spectroscopy (EIS) measurements. The results of EIS measurements performed during 24 h immersion of the investigated samples into the 0.5 M NaCl solution revealed that the layer of silane doped with Ce was more protective than that of the non-modified one. It has been determined that the presence of cerium nitrate in the silane coating can lead to high values of low frequency impedance due to the healing of the defect.

scholarly journals Study of the Corrosion Process of AZ91D Magnesium Alloy during the First Hours of Immersion in 3.5 wt.% NaCl Solution

2018 ◽  
Vol 2018 ◽  
pp. 1-20 ◽  
Author(s):  
Vanessa Mandarano Pinela ◽  
Leandro Antônio de Oliveira ◽  
Mara Cristina Lopes de Oliveira ◽  
Renato Altobelli Antunes
Keyword(s):  
Magnesium Alloy ◽  
Photoelectron Spectroscopy ◽  
Laser Scanning ◽  
Electrochemical Impedance ◽  
Corrosion Process ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Nacl Solution ◽  
X Ray ◽  
Az91d Magnesium Alloy

The AZ91D magnesium alloy was immersed in 3.5 wt.% NaCl solution at room temperature for times ranging from 1 minute up to 72 hours. The aim was to investigate the evolution of the corrosion process using confocal laser scanning microscopy (CLSM), electrochemical impedance spectroscopy, and X-ray photoelectron spectroscopy. The microstructure of the as-received alloy was initially characterized by optical microscopy and scanning electron microscopy (SEM). The crystalline phases were identified by X-ray diffractometry. The main phases were primary-α, eutectic-α, and β (Mg17Al12). Vickers microhardness markings were made on the surface of one etched sample to facilitate the identification of the same region at each different immersion time, thus enabling the observation of the corrosion process evolution. Corrosion initiates at the grain boundaries of the eutectic microconstituent and, then, propagates through primary α-grains. The β-phase was less severely attacked.

Novel green plants extract as corrosion inhibiting coating for steel embedded in concrete

2020 ◽  
Vol 49 (6) ◽  
pp. 501-514
Author(s):  
Ahmed A. ElShami ◽  
Stéphanie Bonnet ◽  
Mohamed Hussein Makhlouf ◽  
A. Khelidj ◽  
N. Leklou
Keyword(s):  
Electrochemical Impedance ◽  
Electrochemical Treatment ◽  
Chloride Ions ◽  
Content Type ◽  
Green Plants ◽  
Steel Rebar ◽  
Wide Range ◽  
The Family ◽  
Corrosion Of Steel ◽  
Plants Extract

Purpose This paper aims to evaluate the ability of Aubepine and Molokhia extract, obtained by cathodic electrochemical treatment (CET), to protect steel rebar against attack by chloride ions in environment of reinforced concrete marine structures. The effect of Aubepine and Molokhia extract was investigated by electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization techniques. Design/methodology/approach This experimental work has achieved particularity to compare the behaviour of two types of treatment (carbon steel treated one time by Aubepine extract and one time by Molokhia extract) submitted to the presence and absence of chloride ions. Findings The results obtained show that the extract solution of the plant could serve as an effective inhibitor for the corrosion of steel. Inhibition was found to increase with increasing concentration of Molokhia extract and for Aubepine extract maximum concentration is 1 g/L. Research limitations/implications Plant extracts and traditional medicinal herbs have become important as an environmentally acceptable, readily available and renewable source for wide range of inhibitors. Originality/value Aubepine and Molokhia extract are novel green plants extract as corrosion inhibiting coating for steel embedded in concrete. Aubepine is a genus of trees in the family Rosaceae and Molokhia is the leaves of Corchorus olitorius. Flavonoids content was found in both of Aubepine and Molokhia extract as green inhibitors for corrosion of metals.

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