scholarly journals Avaliação por impedância eletroquímica da resistência ao transporte de íons sulfato em argamassas armadas contendo resíduos da geração termelétrica / Evaluation by electrochemical impedance of resistance to the transport of sulfate ions in cemented mortars containing residues of thermoelectric generation

2021 ◽  
Vol 7 (11) ◽  
pp. 104750-104762
Author(s):  
Daniele Ferreira Lopes ◽  
Luciana Machado Rodrigues ◽  
Sabrina Neves Da Silva
Keyword(s):  
Electrochemical Impedance ◽  
Thermoelectric Generation ◽  
Sulfate Ions

Effect of Sulfate Ions on the Corrosion Behavior of Steel in Concrete Using Electrochemical Methods

2010 ◽  
Vol 163-167 ◽  
pp. 3049-3054 ◽  
Author(s):  
Jin Jie Shi ◽  
Wei Sun
Keyword(s):  
Corrosion Rate ◽  
Corrosion Behavior ◽  
Chloride Solution ◽  
High Performance ◽  
High Performance Concrete ◽  
Electrochemical Impedance ◽  
Steel Corrosion ◽  
Sulfate Solution ◽  
Cyclic Polarization ◽  
Sulfate Ions

The effect of sulfate ions on the corrosion behavior of steel in ordinary Portland concrete (OPC) and high performance concrete (HPC) were investigated. Steel corrosion was evaluated by means of corrosion potential (Ecorr), linear polarization resistance (LPR), electrochemical impedance spectroscopy (EIS) and cyclic polarization (CP). The electrochemical results indicated that, compared to the pure chloride solution, the presence of sulfate ions in the chloride solution both reduced the time to corrosion initiation and lead to an increase in corrosion rate of steel in OPC specimens; however, the sulfate ions had negligible effect in HPC specimens. Furthermore, the corrosion rate of steel exposed to chloride solution was higher that to the sulfate solution both in OPC and HPC specimens.

Corrosion Behavior for Water Wall Tube Material of 600MW Supercritical Thermal Power Units

2013 ◽  
Vol 331 ◽  
pp. 211-215
Author(s):  
Guo Hua Lu ◽  
Xiao Cui Jiao ◽  
Cun Ren Ma ◽  
Wei Su ◽  
Tian Sheng Chen ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
High Temperature ◽  
Room Temperature ◽  
Electrochemical Impedance ◽  
Thermal Power ◽  
Chloride Ions ◽  
Tube Material ◽  
Sulfate Ions ◽  
Water Wall Tube ◽  
Treatment Water

The influence of chloride ions and sulfate ions on 15CrMoG and 12Cr1MoVG respectively in the simulated Oxygenated Treatment water chemistry conditions with SO42- and Cl- of different concentrations is studied by using polarization curves, electrochemical impedance spectroscopy (EIS) and high temperature coupon tests. The results show that under the experiment condition of room temperature, the two materials are very prone to corrode in solutions containing SO42- and Cl- and the corrosion rate is enhanced with increasing SO42- and Cl- concentration. The corrosion resistance of 15CrMoG is stronger than 12Cr1MoVG for SO42- and Cl-. The corrosivity on 15CrMoG and 12Cr1MoVG of SO42- is lower than Cl-. Under high temperature conditions, the corrosion resistance of 15CrMoG stronger than 12Cr1MoVG in SO42- solutions.

Electrochemical Study of Steel Corrosion in Saturated Calcium Hydroxide Solution with Chloride Ions and Sulfate Ions

CORROSION ◽  
10.5006/2634 ◽  
2018 ◽  
Vol 74 (10) ◽  
pp. 1063-1082 ◽  
Author(s):  
Yunze Xu ◽  
Limin He ◽  
Lujia Yang ◽  
Xiaona Wang ◽  
Yi Huang
Keyword(s):  
Calcium Hydroxide ◽  
Passive Film ◽  
Electrochemical Impedance ◽  
Steel Corrosion ◽  
Chloride Ions ◽  
Localized Corrosion ◽  
General Corrosion ◽  
Sulfate Ions ◽  
Hydroxide Solution ◽  
Q235 Carbon Steel

The corrosion of Q235 carbon steel in the saturated calcium hydroxide solution containing chloride ions and sulfate ions are studied using electrochemical methods and wire beam electrode (WBE) sensor. The cyclic potentiodynamic polarization measurements showed that localized corrosion was mainly induced by the adsorption of chloride ions on the passive film. When the passive film is intact, sulfate ions are not corrosive to the passive film and it can inhibit the pitting initiation caused by the chloride ions. However, the WBE test results indicate that once a stable pit has already formed, sulfate ions cannot mitigate the pitting corrosion, and it can further promote the propagation of the major anodic area. Through the electrochemical impedance spectroscopy measurements, it can be found that the addition of sulfate ions in the solution containing chloride ions will not result in the rise of the general corrosion rate.

EIS study of the corrosion behavior of an organic coating applied on Algerian oil tanker

2020 ◽  
Vol 117 (6) ◽  
pp. 610
Author(s):  
Nadia Hammouda ◽  
Kamel Belmokre
Keyword(s):  
Corrosion Protection ◽  
Electrochemical Impedance ◽  
Paint Film ◽  
Organic Coating ◽  
Diffusion Resistance ◽  
Double Layer Capacitance ◽  
Carbon Steel Surface ◽  
Chloride Environment ◽  
Oil Tanker ◽  
Epoxy Paint

Organic coatings are widely employed in the corrosion protection of most metal surfaces, particularly steel. They provide a barrier against corrosive species present in the environment, due to their high resistance to oxygen, water and ions transport. This study focuses on the evaluation of corrosion protection performance of epoxy paint on the carbon steel surface in chloride environment (3% NaCl) by Electrochemical Impedance Spectroscopy (EIS). The electrochemical behavior of painted surface was estimated by EIS parameters that contained paint film resistance, paint film capacitance and double layer capacitance. On the basis of calculation using EIS spectrums it was observed that pore resistance (Rpore) decreased with the appearance of doubled layer capacitance (Cdl) due to the electrolyte penetration through the film. This was further confirmed by the decrease of diffusion resistance (Rd) which was also the indicator of the deterioration of paint film protectiveness. Microscopic analyses have shown that oxidation dominates the corroded surfaces.

Experimental and Theoretical Comparable Study of Pure and Zinc Porphyrin Surface Modified ZnO Nanorod Arrays for Hybrid Solar Cell Applications

2020 ◽  
pp. 114-119
Keyword(s):  
Solar Cell ◽  
Electrochemical Impedance ◽  
Hybrid Solar Cell ◽  
Cell Performance ◽  
Solar Cell Performance ◽  
Solar Cell Efficiency ◽  
Cell Efficiency ◽  
Annealing Effects ◽  
Vertically Aligned ◽  
Surface Modified

Experimental and theoretical study Porphyrin-grafted ZnO nanowire arrays were investigated for organic/inorganic hybrid solar cell applications. Two types of porphyrin – Tetra (4-carboxyphenyle) TCPP and meso-Tetraphenylporphine (Zinc-TPP)were used to modify the nanowire surfaces. The vertically aligned nanowires with porphyrin modifications were embedded in graphene-enriched poly (3-hexylthiophene) [G-P3HT] for p-n junction nanowire solar cells. Surface grafting of ZnO nanowires was found to improve the solar cell efficiency. There are different effect for the two types of porphyrin as results of Zn existing. Annealing effects on the solar cell performance were investigated by heating the devices up to 225 °C in air. It was found that the cell performance was significantly degraded after annealing. The degradation was attributed to the polymer structural change at high temperature as evidenced by electrochemical impedance spectroscopy measurements.

The Effects of Carbonate-Bicarbonate Concentration on Empirical Corrosion Diagram of Mild Steel as a Material of Geological Disposal Package for High Level Nuclear Wastes

1996 ◽  
Vol 451 ◽  
Author(s):  
Guen Nakayama ◽  
Yuichi Fukaya ◽  
Masatsune Akashi
Keyword(s):  
Mild Steel ◽  
Human Life ◽  
General Corrosion ◽  
Nuclear Wastes ◽  
Bicarbonate Concentration ◽  
Sulfate Ions ◽  
Geological Disposal ◽  
Groundwater Environment ◽  
High Level ◽  
Corrosion Diagram

ABSTRACTIn the scheme for geological disposal of high level radioactive nuclear wastes, the burial pit is to be isolated from the sphere of human life by a multiple-barrier system, which consists of an artificial barrier, composed of a canister, an overpack and a bentonite cushioning layer, and a natural barrier, which is essentially the bedrock. As the greatest as well as essentially the sole detriment to its integrity would be corrosion by groundwater. The groundwater comes to it seeping through the bentonite zone, thereby attaining conceivably the pH of transition from general corrosion to passivity, pHd, the behaviors of mild steel in such a groundwater environment have been examined. It has been shown that the pHd is lowered (enlargement of the passivity domain) with rising temperature and carbonate-bicarbonate concentration, while it is raised (enlargement of the general corrosion region) with increasing concentrations of chloride and sulfate ions.

On the Properties of an Ion Conductive System Incorporated in Hybrid Films

2000 ◽  
Vol 628 ◽  
Author(s):  
G. González ◽  
P. J. Retuert ◽  
S. Fuentes
Keyword(s):  
Electrochemical Impedance ◽  
Ternary Phase Diagram ◽  
Lithium Perchlorate ◽  
Molar Ratio ◽  
Ionic Conductors ◽  
X Ray Diffraction ◽  
Poly Ethylene Oxide ◽  
Ion Conducting ◽  
Poly Ethylene ◽  
High Degree

ABSTRACTBlending the biopolymer chitosan (CHI) with poly (aminopropilsiloxane) oligomers (pAPS), and poly (ethylene oxide) (PEO) in the presence of lithium perchlorate lead to ion conducting products whose conductivity depends on the composition of the mixture. A ternary phase diagram for mixtures containing 0.2 M LiClO4 shows a zone in which the physical properties of the products - transparent, flexible, mechanically robust films - indicate a high degree of molecular compatibilization of the components. Comparison of these films with binary CHI-pAPS nanocomposites as well as the microscopic aspect, thermal behavior, and X-ray diffraction pattern of the product with the composition PEO/CHI/pAPS/LiClO4 1:0.5:0.6:0.2 molar ratio indicates that these films may be described as a layered nanocomposite. In this composite, lithium species coordinated by PEO and pAPS should be inserted into chitosan layers. Electrochemical impedance spectroscopy measurements indicate the films are pure ionic conductors with a maximal bulk conductivity of 1.7*10-5 Scm-1 at 40 °C and a sample-electrode interface capacitance of about 1.2*10-9 F.

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