scholarly journals Study on the Influence of AC Stray Current on X80 Steel under Stripped Coating by Electrochemical Method

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Yanyu Cui ◽  
Tao Shen ◽  
Qingmiao Ding
Keyword(s):  
Current Density ◽  
Electrochemical Method ◽  
Corrosion Current Density ◽  
Corrosion Current ◽  
Open Circuit ◽  
Stray Current ◽  
Ac Power ◽  
Initial Stage ◽  
X80 Steel ◽  
Ac Interference

The effect of AC stray current density on corrosion behavior of X80 steel with stripped coating defects was studied by electrochemical method. The experimental results showed that the open circuit potential of X80 steel was shifted negatively due to the existence of AC interference. The degree of negative shift increased with the increasing of AC stray current density. And the potential after the cut of AC interference was still more negative than before. That is, the corrosion interference continued after cutting the AC power. In the initial stage of the experiment, the corrosion current density with 30A/m2 AC stray current interference was about 1.4 times of that without AC interference, while the corrosion current density with 50A/m2 AC stray current interference was about two times of that without AC interference.

Corrosion behavior of X80 steel under disbond coating interfered with AC

2019 ◽  
Vol 66 (6) ◽  
pp. 704-718
Author(s):  
Qingmiao Ding ◽  
Zili Li ◽  
Tao Shen ◽  
Gan Cui
Keyword(s):  
Corrosion Behavior ◽  
Current Density ◽  
Corrosion Current Density ◽  
Corrosion Potential ◽  
Corrosion Current ◽  
The Self ◽  
Stray Current ◽  
Content Type ◽  
X80 Steel ◽  
Protection Potential

Purpose This paper aims to research the corrosion behavior of the metal under the disbonded coatings interfered with AC through electrochemical method. Design/methodology/approach The corrosion behavior of the metal under disbond coating interfered with alternate stray current (AC) was studied by electrochemical methods using the rectangular coating disbonded simulator. The obtained data from electrode potential test, electrochemical impedance spectroscopy (EIS) and polarization curves in simulated soil solution indicated that under the natural corrosion condition, the self-corrosion potential and the corrosion current density of the metal at different depths under disbond coating had obviously changed if there was AC interference. Findings The self-corrosion potential of the metal at the same depths under disbond coating shifted negatively with the rising of the AC voltage. Under the condition of cathode polarization, there was still obvious potential gradient with the extension of the deep peeling of the coating gap, and the corrosion current density of the test points was minimum, and the protection effect was best when the cathode protection potential was −1.0 V. When the metal was applied with over-protection, the corrosion rate of the metal increased as AC stray current flowing through it increased. Originality/value This paper used the rectangular aperture device to study the corrosion behavior of X80 steel under the disbonded coatings through electrochemical methods when the AC stray current interference voltage was 0V, 1V, 5V or 10V and the protection potential was 0V, −0.9V, −1.0V, −1.2V or −1.3V, respectively. There is great significance to the safe operation and long-term service of pipeline steel in soil environment.

scholarly journals Effect of Alternating Stray Current Density on Corrosion Behavior of X80 Steel under Disbonded Coating

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Qing-Miao Ding ◽  
Yong-Xiang Qin ◽  
Tao Shen ◽  
Yu-ning Gao
Keyword(s):  
Corrosion Behavior ◽  
Current Density ◽  
Corrosion Current Density ◽  
Corrosion Current ◽  
Negative Deviation ◽  
Stray Current ◽  
Cathode Area ◽  
X80 Steel ◽  
Wire Beam Electrode ◽  
Disbonded Coating

In this paper, the effect of alternating stray current (AC) density on the corrosion behavior of X80 steel under disbonded coating was studied by electrochemical methods, wire beam electrode (WBE) technology, and surface observation technology. The results showed that under the interference of different AC densities, the corrosion potential of X80 steel under disbonded coating underwent negative deviation, and the degree of negative deviation increased with the increase of AC density. The corrosion current density of X80 steel under disbonded coating with the action of 0~100 A/m2 AC density had few differences. While the corrosion current density of X80 steel with the action of 200~300 A/m2 AC density increased and the corrosion current density was higher than that under low AC density. The cathode area of the wire beam electrode under disbonded coating is mainly distributed outside and the edge of the gap between disbonded coating and X80 steel, while the anode area is mainly distributed inside the gap.

scholarly journals An electrochemical method to investigate the effects of compound composition on gold dissolution in thiosulfate solution

2020 ◽  
Vol 9 (1) ◽  
pp. 496-502 ◽  
Author(s):  
Zhaohui Zhang ◽  
Bailong Liu ◽  
Mei Wu ◽  
Longxin Sun
Keyword(s):  
Dissolution Rate ◽  
Current Density ◽  
Polarization Resistance ◽  
Electrochemical Method ◽  
Corrosion Current Density ◽  
Corrosion Potential ◽  
Corrosion Current ◽  
Gold Dissolution ◽  
Tafel Polarization ◽  
Edta Solution

AbstractThe electrochemical behavior of gold dissolution in the Cu2+–NH3–S2O32−–EDTA solution has been investigated in detail by deriving and analyzing the Tafel polarization curve, as this method is currently widely implemented for the electrode corrosion analysis. The dissolution rate of gold in Cu2+–NH3–S2O32−–EDTA solution was determined based on the Tafel polarization curves, and the effects of various compound compositions in a Cu2+–NH3–S2O32−–EDTA mixture on the corrosion potential and corrosion current density were analyzed. The results showed that the corrosion potential and polarization resistance decreased, whereas the corrosion current density increased for certain concentrations of S2O32−–NH3–Cu2+ and EDTA, indicating that the dissolution rate of gold had changed. The reason for promoting the dissolution of gold is also discussed.

Evaluation on the Corrosion Resistance Improvement by Dipping to Inhibitor Solution of Galvanizing Steel

2011 ◽  
Vol 117-119 ◽  
pp. 1365-1369
Author(s):  
Kyung Man Moon ◽  
Myung Hoon Lee
Keyword(s):  
Corrosion Resistance ◽  
Current Density ◽  
Electrochemical Method ◽  
Corrosion Current Density ◽  
Rapid Development ◽  
Corrosion Current ◽  
Industrial Society ◽  
Chromate Treatment ◽  
Resistance Improvement ◽  
Inhibitor Solution

Galvanizing method is being widely used to the numerous constructional steels such as a guard rail of high way, various types of structural steel for manufacturing ship and for some other fields etc.. However, galvanized structures inevitably may be corroded rapidly with increasing exposed time because the rate of environmental contamination is accelerating due to the rapid development of industrial society. Therefore, it is necessary to improve the corrosion resistance of the galvanizing film through various methods such as variation of chemical composition of galvanizing bath, chromate treatment and coating treatment etc.. In this study, three types of the test specimens, that is, pure galvanizing, galvalume and chromate treated steels were immersed at inhibitor solution. And the effect of inhibitor for their corrosion resistance improvement was comparatively investigated with an electrochemical method. Corrosion current density of the original galvanizing and galvalume steel exhibited the highest and lowest value respectively in seawater. However, the corrosion resistance of these samples was considerably improved by dipped to a inhibitor solution(H3PO4+ Zn(NO3)2+Q). In particular, the galvanizing steel which dipped to the inhibitor solution exhibited the lowest corrosion current density due to the best effect of corrosion resistance improvement compared to other test specimens.

The Galvanic Corrosion Behaviors of 13Cr-N80 Steel Couples in NaCl Solution at Different Temperature

2013 ◽  
Vol 750-752 ◽  
pp. 467-472 ◽  
Author(s):  
Ling Wu ◽  
Fa Qin Xie ◽  
Xiao Fei Yao
Keyword(s):  
Current Density ◽  
Electrochemical Method ◽  
Corrosion Current Density ◽  
Galvanic Corrosion ◽  
Corrosion Current ◽  
Potential Difference ◽  
Nacl Solution ◽  
N80 Steel ◽  
Corrosion Behaviors ◽  
Increasing Temperature

Electrochemical method was employed to investigate galvanic corrosion behaviors of super13Cr and N80 couples in 5% NaCl solution at different temperature. Corrosion morphologies and products of the couples were analyzed by SEM, EDS and XRD. The results show that there existed distinct potential difference between super13Cr and N80 with different degree of corrosion in 5% NaCl solution at different temperature. N80 was accelerated to corrode as anode, however, super 13Cr was protected as cathode when their coupling. In order to avoid galvanic corrosion, the super 13Cr-N80 couples could not be used without any protection of N80 from 25°C to 80°C. Corrosion current density of the super13Cr-N80 couples increased with increasing temperature in 5% NaCl solution, as well as the more serious corrosion of N80, of which corrosion products are Fe3O4.

Electrochemical Aspects of Etching and Passivation of Silicon in Alkaline Solutions

1995 ◽  
Vol 386 ◽  
Author(s):  
Joong S. Jeon ◽  
Srini Raghavan
Keyword(s):  
Current Density ◽  
Corrosion Current Density ◽  
Open Circuit Potential ◽  
Corrosion Current ◽  
Open Circuit ◽  
High Resistivity ◽  
Alkaline Solutions ◽  
Current Densities ◽  
Passivation Potential ◽  
P Type

ABSTRACTElectrochemical polarization experiments were performed on Si wafers in ammoniacal solutions maintained at a pH in the range of 9.5 to 11.5. Anodic polarization of silicon yielded curves which are typical for materials that undergo passivation. The values of open circuit potential and passivation potential for p-type Si wafers were more anodic than for the n-type Si wafers. Corrosion current density of p-type Si wafers of low resistivity was lower than that of wafers of high resistivity. Corrosion current densities correlated well with surface roughness induced in alkaline solutions. Addition of surfactant or H2O2 to alkaline solutions reduced critical current density for passivation and corrosion current density.

Corrosion Behavior of Cobalt Alloy Coating in NaCl Solution

2020 ◽  
Vol 993 ◽  
pp. 1086-1094
Author(s):  
Yue Hou ◽  
Hai Yan Chen ◽  
Li Fan ◽  
Yu Rong Xu ◽  
Qian Cheng ◽  
...  
Keyword(s):  
Current Density ◽  
Corrosion Current Density ◽  
Electrochemical Impedance ◽  
Corrosion Behaviour ◽  
Alloy Coating ◽  
Corrosion Current ◽  
Eutectic Structure ◽  
Open Circuit ◽  
The Self ◽  
Nacl Solution

Two kinds of Co-based coatings were obtained through the laser cladding (LC) and plasma transfer arc (PTA) process. The phase composition and microstructure of the coatings were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The corrosion behaviour of the different Co-based alloy coatings in 3.5wt% NaCl solution were compared by means of open-circuit potential (OCP), polarization curve and electrochemical impedance spectroscopy (EIS). XRD and SEM measurements demonstrated that the microstructures of the two different Co-based coatings were composed of primary solid solution γ-Co and eutectic structure Cr23C6, whereas, fish-bone typed (CoCrW)6C was also detected in the coating produced by PTA. The polarization curves and EIS results showed that in 3.5wt% NaCl solution, the passivation zones of the two coatings occurred obviously, the self-corrosion potential of the two coatings shifted to the right, and the self-corrosion current density was much smaller than that of the substrate. In addition, the Co-based coating made by LC showed lower corrosion current density and larger diameter of a capacitive arc than that of Co-based coating produced by PTA, indicating the LC coating had the best corrosion resistance in the three samples.

ANTICORROSION AND REPAIR BEHAVIOR OF REC–SiO2 SILANE FILM ON CARBON STEEL

2021 ◽  
pp. 2150098
Author(s):  
JIABIN TANG ◽  
YIHE YAO ◽  
MANLI GUO ◽  
JIBO JIANG ◽  
HAISHAN CONG ◽  
...  
Keyword(s):  
Carbon Steel ◽  
Current Density ◽  
Corrosion Current Density ◽  
Condensation Reaction ◽  
Morphological Characteristics ◽  
Corrosion Current ◽  
Element Distribution ◽  
Open Circuit ◽  
Self Healing

The synergistic effect of Ce[Formula: see text] and SiO2 nanoparticles (NPs) composite silane film on the corrosion resistance of carbon steel was researched. The preparation method of silane film is mainly hydrolysis of bis-1,2-(triethoxysilyl)ethane (BTSE) and 3-glycidoxypropyltrimethoxysilane (KH-560) under acidic conditions and condensation reaction. EDX and SEM were employed to analyze the element distribution and morphological characteristics of the coating, which confirmed the coatings were crack-free and even distribution of surface elements. The chemical bond structure characteristics of the silane film on carbon steel were analyzed by XPS, and compared with the silane film after ultrasound. It proved the bonding force of the silane film. The best corrosion current density of the silane film containing cerium is 4.65 [Formula: see text]Acm[Formula: see text]. The [Formula: see text] obtained by simulating the corrosion circuit through Zsimpwin software is 22.02[Formula: see text]k[Formula: see text]cm[Formula: see text]. On this basis, by adding different concentrations of SiO2 NPs, the corrosion current density can reach a minimum of 0.70 [Formula: see text]Acm[Formula: see text]. The simulated polarization curve [Formula: see text] was 65.13[Formula: see text]k[Formula: see text]cm[Formula: see text]. In the long-term open-circuit potential test, the potential of the silane film containing rare earth cerium increased to 38[Formula: see text]mV at a certain stage, which proves the self-healing performance of the film.

scholarly journals Prediction Model of Corrosion Current Density Induced by Stray Current Based on QPSO-Driven Neural Network

Complexity ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Chengtao Wang ◽  
Wei Li ◽  
Gaifang Xin ◽  
Yuqiao Wang ◽  
Shaoyi Xu
Keyword(s):  
Neural Network ◽  
Particle Swarm Optimization ◽  
Current Density ◽  
Corrosion Current Density ◽  
Learning Algorithm ◽  
Particle Swarm ◽  
Electrochemical Corrosion ◽  
Corrosion Current ◽  
Stray Current ◽  
Swarm Optimization

The buried pipelines and metallic structures in subway systems are subjected to electrochemical corrosion under the stray current interference. The corrosion current density determines the degree and the speed of stray current corrosion. A method combining electrochemical experiment with the machine learning algorithm was utilized in this research to study the corrosion current density under the coupling action of stray current and chloride ion. In this study, a quantum particle swarm optimization-neural network (QPSO-NN) model was built up to predict the corrosion current density in the process of stray current corrosion. The QPSO algorithm was employed to optimize the updating process of weights and biases in the artificial neural network (ANN). The results show that the accuracy of the proposed QPSO-NN model is better than the model based on backpropagation neural network (BPNN) and particle swarm optimization-neural network (PSO-NN). The accuracy distribution of the QPSO-NN model is more stable than that of the BPNN model and the PSO-NN model. The presented model can be used for the prediction of corrosion current density and provides the possibility to monitor the stray current corrosion in subway system through an intelligent learning algorithm.

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