Corrosion Monitoring of Reinforced Steel Embedded in Cement Mortar under Wet-And-Dry Cycles by Electrochemical Impedance Spectroscopy

The primary objective of the present work is to measure the corrosion rate of reinforcing steel embedded in concrete structures in a simulated marine environment of high chloride concentration. The selection of a single frequency that corresponds to the solution resistance and single frequency that corresponds to the charge transfer resistance were performed and measurements were carried out in a relatively faster time. A total of seven cement mortar specimens were prepared. The effect of varying cover thickness (5–50 mm) and rebar distance (10–80 mm) on the electrical resistance of the concrete and corrosion rate of the steel was examined. To simulate the corrosion of reinforced concrete in a marine environment, cement mortars were exposed to 25 wet–dry cycles that involve an immersion for 8 h in 3 wt.% NaCl solution and drying time of 16 h under room temperature. Alternative current (AC) impedance measurements were carried out within a frequency range from 100 kHz to 1 mHz. Results show that the formation of rust layers on rebars has caused a significant decrease in the maximum phase shift to θ = −30°. An accelerated corrosion rate of the rebars was observed during drying stage.

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Electrochemical Immunosensor for the Quantification of S100B at Clinically Relevant Levels Using a Cysteamine Modified Surface

Sensors ◽

10.3390/s21061929 ◽

2021 ◽

Vol 21 (6) ◽

pp. 1929

Author(s):

Alexander Rodríguez ◽

Francisco Burgos-Flórez ◽

José D. Posada ◽

Eliana Cervera ◽

Valtencir Zucolotto ◽

...

Keyword(s):

Frequency Analysis ◽

Surface Characterization ◽

Electrochemical Impedance ◽

Limit Of Detection ◽

Neuronal Damage ◽

Charge Transfer Resistance ◽

Single Frequency ◽

Response Analysis ◽

Transfer Resistance ◽

Therapeutic Decisions

Neuronal damage secondary to traumatic brain injury (TBI) is a rapidly evolving condition, which requires therapeutic decisions based on the timely identification of clinical deterioration. Changes in S100B biomarker levels are associated with TBI severity and patient outcome. The S100B quantification is often difficult since standard immunoassays are time-consuming, costly, and require extensive expertise. A zero-length cross-linking approach on a cysteamine self-assembled monolayer (SAM) was performed to immobilize anti-S100B monoclonal antibodies onto both planar (AuEs) and interdigitated (AuIDEs) gold electrodes via carbonyl-bond. Surface characterization was performed by atomic force microscopy (AFM) and specular-reflectance FTIR for each functionalization step. Biosensor response was studied using the change in charge-transfer resistance (Rct) from electrochemical impedance spectroscopy (EIS) in potassium ferrocyanide, with [S100B] ranging 10–1000 pg/mL. A single-frequency analysis for capacitances was also performed in AuIDEs. Full factorial designs were applied to assess biosensor sensitivity, specificity, and limit-of-detection (LOD). Higher Rct values were found with increased S100B concentration in both platforms. LODs were 18 pg/mL(AuES) and 6 pg/mL(AuIDEs). AuIDEs provide a simpler manufacturing protocol, with reduced fabrication time and possibly costs, simpler electrochemical response analysis, and could be used for single-frequency analysis for monitoring capacitance changes related to S100B levels.

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Sacrificial Dissolution of Zinc Electroplated and Cold Galvanized Coated Steel in Saline and Soil Environments: A Comparison

Materials ◽

10.3390/ma14040744 ◽

2021 ◽

Vol 14 (4) ◽

pp. 744

Author(s):

Ameeq Farooq ◽

Umer Masood Chaudry ◽

Ahsan Saleem ◽

Kashif Mairaj Deen ◽

Kotiba Hamad ◽

...

Keyword(s):

Corrosion Rate ◽

Electrochemical Impedance ◽

Saline Soil ◽

Steel Substrate ◽

Salt Spray ◽

Steel Structures ◽

Open Circuit ◽

Cyclic Polarization ◽

Transfer Resistance ◽

Soil Solutions

To protect steel structures, zinc coatings are mostly used as a sacrificial barrier. This research aims to estimate the dissolution tendency of the electroplated and zinc-rich cold galvanized (ZRCG) coatings of a controlled thickness (35 ± 1 μm) applied via brush and dip coating methods on the mild steel. To assess the corrosion behavior of these coated samples in 3.5% NaCl and 10% NaCl containing soil solutions, open circuit potential (OCP), cyclic polarization (CP), and electrochemical impedance spectroscopy (EIS) tests were performed. The more negative OCP and appreciably large corrosion rate of the electroplated and ZRCG coated samples in 3.5% NaCl solution highlighted the preferential dissolution of Zn coatings. However, in saline soil solution, the relatively positive OCP (>−850 mV vs. Cu/CuSO4) and lower corrosion rate of the electroplated and ZRCG coatings compared to the uncoated steel sample indicated their incapacity to protect the steel substrate. The CP scans of the zinc electroplated samples showed a positive hysteresis loop after 24 h of exposure in 3.5% NaCl and saline soil solutions attributing to the localized dissolution of the coating. Similarly, the appreciable decrease in the charge transfer resistance of the electroplated samples after 24 h of exposure corresponded to their accelerated dissolution. Compared to the localized dissolution of the electroplated and brush-coated samples, the dip-coated ZRCG samples exhibited uniform dissolution during the extended exposure (500 h) salt spray test.

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Effects of Propargyl Alcohol on Electrochemical Behaviors of AZ91 Magnesium Alloy Anode in 3.5% NaCl Solution

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.750-752.1137 ◽

2013 ◽

Vol 750-752 ◽

pp. 1137-1140

Author(s):

Zu Xiao Yu ◽

Shi Xiong Hao ◽

Qing Shan Fu

Keyword(s):

Magnesium Alloy ◽

Corrosion Rate ◽

Electrochemical Impedance ◽

Propargyl Alcohol ◽

Nacl Solution ◽

Az91 Magnesium Alloy ◽

Transfer Resistance ◽

Electrochemical Behaviors ◽

Alloy Anode ◽

Az91 Magnesium

To improve corrosion rates and activation properties of AZ91 magnesium alloy anode, effects of additives (propargyl alcohol) on electrochemical behaviors of AZ91 magnesium alloy in 3.5% NaCl solution have been examined by studying corrosion rate, polarization, open circuit potential (Eocp) and transfer resistance values (Rt) of electrochemical impedance spectroscopy(EIS). The results show that propargyl alcohol not only decreases corrosion rate of AZ91 magnesium alloy anode, corrosion-inhibition ratio is 64.6%, but also increases activation properties of AZ91 when 1.0 % propargyl alcohol added into 3.5% NaCl solution. The current density of AZ91 reaches 9.46 mA.cm-2 at-1.35V. Its active potential (Eact ) is-1.527 V , and Eocp is-1.556 V.

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Long-term corrosion monitoring of carbon steels and environmental correlation analysis via the random forest method

npj Materials Degradation ◽

10.1038/s41529-021-00211-3 ◽

2022 ◽

Vol 6 (1) ◽

Author(s):

Qing Li ◽

Xiaojian Xia ◽

Zibo Pei ◽

Xuequn Cheng ◽

Dawei Zhang ◽

...

Keyword(s):

Random Forest ◽

Corrosion Rate ◽

Atmospheric Corrosion ◽

Chloride Concentration ◽

Carbon Steels ◽

Sensor Data ◽

Corrosion Monitoring ◽

Atmospheric Conditions ◽

Data Points

AbstractIn this work, the atmospheric corrosion of carbon steels was monitored at six different sites (and hence, atmospheric conditions) using Fe/Cu-type atmospheric corrosion monitoring technology over a period of 12 months. After analyzing over 3 million data points, the sensor data were interpretable as the instantaneous corrosion rate, and the atmospheric “corrosivity” for each exposure environment showed highly dynamic changes from the C1 to CX level (according to the ISO 9223 standard). A random forest model was developed to predict the corrosion rate and investigate the impacts of ten “corrosive factors” in dynamic atmospheres. The results reveal rust layer, wind speed, rainfall rate, RH, and chloride concentration, played a significant role in the corrosion process.

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Corrosion Behaviour of Automotive Steel Sheets Depending on the Degree of Deformation

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.635.57 ◽

2014 ◽

Vol 635 ◽

pp. 57-60 ◽

Cited By ~ 1

Author(s):

Janette Brezinová ◽

Juraj Koncz ◽

Miroslav Tomáš ◽

Ján Slota

Keyword(s):

Corrosion Rate ◽

Steel Sheet ◽

Electrochemical Impedance ◽

Corrosion Behaviour ◽

Experimental Studies ◽

Corrosion Monitoring ◽

Corrosion Properties ◽

Degree Of Deformation ◽

Steel Sheets ◽

Automotive Steel

This paper presents the results of research aimed to measuring the corrosion properties of automotive steel sheets. The degree of deformation influence to the corrosion properties of the steel sheet for car body parts has been proven by the modern methods of corrosion monitoring such as Electrochemical Impedance Spectroscopy. Corrosion rate was assessed using electrochemical methods in 0.1 M solution of NaCl. Experimental studies have pointed out if degree of deformation increases the corrosion rate of the steel sheet increases as well.

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Environmentally favorable magnesium phosphate anti-corrosive coating on carbon steel and protective mechanisms

Scientific Reports ◽

10.1038/s41598-020-79613-3 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Siyi Yin ◽

Haiyan Yang ◽

Yinghao Dong ◽

Chengju Qu ◽

Jinghui Liu ◽

...

Keyword(s):

Linear Polarization ◽

Electrochemical Impedance ◽

Salt Spray ◽

Steel Structures ◽

Polymer Coatings ◽

Carbon Steels ◽

Magnesium Phosphate ◽

Corrosion Monitoring ◽

Nacl Solution ◽

Transfer Resistance

AbstractPolymer coatings are commonly used to protect carbon steels from corrosion but they are susceptible to weathering and many of them have environmental concerns. Therefore, we studied the possibility of an environmentally favorable inorganic magnesium phosphate cement (MPC) coating for protecting mild steel. A formulation suitable for coating steel was developed by compositional modification [i.e., incremental replacement of dead-burned magnesia (MgO) with magnesium hydroxide (Mg(OH)2)] to a road-repair MPC. This modification yielded an acceptable working time and prevented pore formation at the coating-steel interface. Corrosion monitoring by linear polarization and electrochemical impedance spectroscopy for 14 days found that, the MPC coating substantially increased the linear polarization resistance (Rp) [e.g., day 1: (8.2 ± 1.7) × 103 (nadir value) vs. 495 ± 55 Ω cm−2] and charge transfer resistance (Rct) (e.g., day 1: 9.3 × 103 vs. 3.8 × 102 Ω cm−2). The coated steel underwent neutral sodium chloride (NaCl) salt spray for 2400 h without visible rusting. Immersion for 24 h in liquids simulating the pore fluid indicated that, passivation by the excess MgO in the coating was a major contributor to its anti-corrosive property. Tafel polarization in the liquids found that, corrosion current density (Icorr) followed the rank: 3.5% NaCl solution (6.0 µA cm−2) > 3.5% NaCl solution containing MgO (3.6 µA cm−2) > 3.5% NaCl solution containing fragmented MPC (1.7 µA cm−2), suggesting that a physical barrier effect and dissolved phosphate ions improved its protection. This study shows that, MPC coating is a promising durable and environmentally favorable anti-corrosive material for protecting steel structures in some applications.

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Influence of processing technology on electrochemical corrosion behavior of Ti-6Al-4V alloys

CORROSION ◽

10.5006/3490 ◽

2021 ◽

Author(s):

Caiyun Bai ◽

Peifeng Li ◽

Tieqiang Gang ◽

Jian Li ◽

Min Wei ◽

...

Keyword(s):

Corrosion Resistance ◽

Corrosion Rate ◽

Corrosion Behavior ◽

Electrochemical Impedance ◽

Electrochemical Corrosion ◽

Electrochemical Impedance Spectra ◽

Transfer Resistance ◽

Electrochemical Corrosion Behavior ◽

Corrosion Behaviors ◽

3D Printed

Ti-6Al-4V alloys are typically used for biomedical implants, aerospace components and offshore equipment, where corrosion resistance is critical. In the present paper, the electrochemical corrosion behaviors of Ti-6Al-4V alloys made by different traditional processing and 3D printing technologies in seawater, 3.5 wt.% NaCl, 3.5 wt.% HCl, 5 wt.% HCl and 10 wt.% HCl solutions were studied through polarization curve and electrochemical impedance spectra (EIS) analyses. The influences of microstructure and printing parameters on the corrosion behaviors of Ti-6Al-4V alloys were analyzed. In addition, the corrosion current density, film resistance and charge transfer resistance of traditionally processed Ti-6Al-4V and 3D printed Ti-6Al-4V in the five solutions were compared. The results show that Ti-6Al-4V possesses a better corrosion resistance in seawater than in 3.5 wt.% NaCl, and that the corrosion rate increases with the HCl concentration. Besides, 3D printed Ti-6Al-4V shows a higher corrosion rate in comparison with traditionally processed Ti-6Al-4V because pores are effortless to enrich Cl-. Finally, the ratio of laser power to its scanning speed and the phase constituent composition of the alloy have slight influences on its electrochemical corrosion behavior. It is suggested that for the 3D printed alloy, the deterioration of mechanical properties induced by corrosion damage during servicing should be assessed and considered.

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The effect of strain amount on corrosion behavior of EDDQ steel sheet

Koroze a ochrana materialu ◽

10.1515/kom-2016-0020 ◽

2016 ◽

Vol 60 (4) ◽

pp. 128-131

Author(s):

J. Brezinová ◽

J. Slota ◽

M. Tomáš ◽

J. Koncz

Keyword(s):

Electrochemical Impedance Spectroscopy ◽

Impedance Spectroscopy ◽

Corrosion Rate ◽

Corrosion Behavior ◽

Steel Sheet ◽

Electrochemical Impedance ◽

Experimental Studies ◽

Corrosion Monitoring ◽

Corrosion Properties ◽

Modern Methods

Abstract This paper presents the results of research aimed to measuring the corrosion properties of EDDQ steel sheet. The strain amount influence to the corrosion properties of the steel sheet for drawn parts has been proven by the modern methods of corrosion monitoring such as Electrochemical Impedance Spectroscopy. Corrosion rate was assessed using electrochemical methods in 0.1 M solution of NaCl. Experimental studies have pointed out if strain amount increases the corrosion rate of the steel sheet increases too.

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Protection of Steel Rebar in Salt-Contaminated Cement Mortar Using Epoxy Nanocomposite Coatings

International Journal of Electrochemistry ◽

10.1155/2018/8386426 ◽

2018 ◽

Vol 2018 ◽

pp. 1-10 ◽

Cited By ~ 2

Author(s):

The Huu Nguyen ◽

Tuan Anh Nguyen

Keyword(s):

Corrosion Resistance ◽

Critical Level ◽

Cement Mortar ◽

Electrochemical Impedance ◽

Chloride Concentration ◽

Corrosion Current ◽

Chloride Ions ◽

Coated Steel ◽

Steel Rebar ◽

Electrochemical Monitoring

Epoxy reinforced with two kinds of nanoparticles dealing with nano-SiO2 and nano-Fe2O3 was coated on steel rebar embedded in a chloride contaminated cement mortar. NaCl was added to the fresh Portland cement paste (at 0.3% and 0.5% by weight of cement) to simulate the chloride contamination at the critical level. The effect of incorporating nanoparticles on the corrosion resistance of epoxy-coated steel rebar was investigated by linear potentiodynamic polarization and electrochemical impedance spectroscopy. For the 0.3 wt.% chloride mortars, the electrochemical monitoring of the coated steel rebars during immersion for 56 days in 0.1 M NaOH solutions suggested the beneficial role of nano-Fe2O3 particles in significantly improving the corrosion resistance of the epoxy-coated rebar. After 56 days of immersion, the nano-Fe2O3 reduced the corrosion current of epoxy-coated rebar by a factor of 7.9. When the chloride concentration in the cement mortar was 0.5 wt.%, the incorporation of nanoparticles into the epoxy matrix did not enhance the corrosion resistance of epoxy coating for the rebar. At this critical level, chloride ions initiated rebar corrosion through nanoparticles at the epoxy/rebar interface.

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Improvement of Ti/RuO2–IrO2 Anode Lifetime and Electrocatalytical Properties by Using an Eco-Friendly Thermal Decomposition Method Using Polyvinyl Alcohol as Solvent

10.26434/chemrxiv.7991129 ◽

2019 ◽

Author(s):

Charlys Bezerra ◽

Géssica Santos ◽

Marilia Pupo ◽

Maria Gomes ◽

Ronaldo Silva ◽

...

Keyword(s):

Thermal Decomposition ◽

Polyvinyl Alcohol ◽

High Efficiency ◽

Electrochemical Impedance ◽

Pechini Method ◽

Low Cost ◽

Charge Transfer Resistance ◽

Transfer Resistance ◽

Calcination Temperatures ◽

Service Lifetime

Electrochemical oxidation processes are promising solutions for wastewater treatment due to their high efficiency, easy control and versatility. Mixed metal oxides (MMO) anodes are particularly attractive due to their low cost and specific catalytic properties. Here, we propose an innovative thermal decomposition methodology using <a>polyvinyl alcohol (PVA)</a> as a solvent to prepare Ti/RuO2–IrO2 anodes. Comparative anodes were prepared by conventional method employing a polymeric precursor solvent (Pechini method). The calcination temperatures studied were 300, 400 and 500 °C. The physical characterisation of all materials was performed by X-ray diffraction and scanning electron microscopy coupled with energy dispersive spectroscopy, while electrochemical characterisation was done by cyclic voltammetry, accelerated service lifetime and electrochemical impedance spectroscopy. Both RuO2 and IrO2 have rutile-type structures for all anodes. Rougher and more compact surfaces are formed for the anodes prepared using PVA. Amongst temperatures studied, 300 °C using PVA as solvent is the most suitable one to produce anodes with expressive increase in voltammetric charge (250%) and accelerated service lifetime (4.3 times longer) besides reducing charge-transfer resistance (8 times lower). Moreover, the electrocatalytic activity of the anodes synthesised with PVA toward the Reactive Blue 21 dye removal in chloride medium (100 % in 30 min) is higher than that prepared by Pechini method (60 min). Additionally, the removal total organic carbon point out improved mineralisation potential of PVA anodes. Finally, this study reports a novel methodology using PVA as solvent to synthesise Ti/RuO2–IrO2 anodes with improved properties that can be further extended to synthesise other MMO compositions.

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