Influence of the Cathodic Charging Current on Electrochemical Behaviors of X80 Steel in an Simulated Acidic Soil Solution

2013 ◽  
Vol 750-752 ◽  
pp. 2179-2182
Author(s):  
Jie Zhang ◽  
Jing Li ◽  
Qian Hu ◽  
Feng Huang
Keyword(s):  
Soil Solution ◽  
Electrode Surface ◽  
Electrochemical Impedance ◽  
Open Circuit ◽  
Acidic Soil ◽  
Anodic Process ◽  
Electrochemical Behaviors ◽  
Charging Current ◽  
X80 Steel ◽  
Cathodic Charging

The electrochemical behaviors of X80 steel under different charging current in an acidic soil solution were investigated by open circuit potential, potentiodynamic scan and electrochemical impedance spectroscopy. Results show that cathodic charging promotes the formation of corrosion product on the electrode surface, accordingly, the OCP changes slightly. The hydrogen ions on electrode surface are exhausted during the charging process, therefore the cathodic reaction is restrained meanwhile the anodic process iron dissolution increases. EIS result shows that the corrosion rate under OCP was inhibited by cathodic charging. However, the anodic process was enhanced by charging under-0.4 VSCE.

scholarly journals Effect of DC Currents and Strain on Corrosion of X80 Steel in a Near-Neutral Environment

Metals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1601
Author(s):  
Zeyu Ma ◽  
Wei Wu ◽  
Pengxiong Zhao ◽  
Yong Dan
Keyword(s):  
Electrochemical Impedance ◽  
Steel Corrosion ◽  
Open Circuit ◽  
Applied Strain ◽  
Stray Current ◽  
Corrosion Scale ◽  
Surface Analysis Techniques ◽  
Neutral Soil ◽  
X80 Steel ◽  
Current Densities

The corrosion behavior of X80 steel in a near-neutral soil-simulated solution under various DC stray currents and applied strains was investigated using electrochemical measurements (open circuit potential, linear polarization, and electrochemical impedance spectroscopy) and surface analysis techniques. Our results show that a DC stray current has a substantially greater effect on steel corrosion compared to applied strain. However, strain could slow down the corrosion rate in specific conditions by affecting the composition of corrosion products and the structure of the corrosion scale on the surface of the steel. Although the porosity of the corrosion scale of steel without an applied strain will increase with increasing DC currents, once strain is applied, the corrosion scale will become denser. Furthermore, both DC currents and strain can promote steel pitting, and the number and size of pitting holes will increase significantly with an increase in current densities.

Effect of pyrite on the electrochemical behavior of chalcopyrite at different potentials in pH 1.8 H2SO4

2019 ◽  
Vol 43 (11-12) ◽  
pp. 493-502
Author(s):  
Qingyou Liu ◽  
Shuai Wang ◽  
Miao Chen ◽  
Yi Yang
Keyword(s):  
Electrochemical Impedance ◽  
Saturated Calomel Electrode ◽  
Surface Characteristics ◽  
Charge Transfer Resistance ◽  
Open Circuit ◽  
Electrochemical Dissolution ◽  
Passive Region ◽  
Transfer Resistance ◽  
Electrochemical Behaviors ◽  
Passive Resistance

Chalcopyrite is the most abundant, but also one of the most refractory, copper sources. One way to enhance chalcopyrite’s electrochemical dissolution is by mixing it with pyrite. To understand how and to what extent pyrite affects chalcopyrite’s electrochemical dissolution at different potentials, the electrochemical behaviors of chalcopyrite, pyrite, and chalcopyrite–pyrite couples in pH 1.8 H2SO4 were studied by potentiodynamic and electrochemical impedance spectroscopy. Potentiodynamic curves showed their different electrochemical reaction states and electrode surface characteristics. From open-circuit potential to 470 mV (vs saturated calomel electrode), chalcopyrite–pyrite was passivated with Cu1− xFe1− yS2 [Formula: see text]; from 470 to 580 mV, trans-passive dissolution occurred, and in the passive region, Cu1− xFe1− yS2 transformed into Cu1− x− zS2; from 580 to 700 mV was an active region; and a pseudo-passive region was formed with CuS when the potential was above 700 mV. The smaller charge transfer resistance and passive resistance, as well as the smaller inductive relaxation, revealed how and to what extent the coupled pyrite accelerated the electrochemical dissolution of chalcopyrite.

scholarly journals Electrochemical Investigation of Corrosion of X80 Steel under Elastic and Plastic Tensile Stress in CO2 Environment

Metals ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 949 ◽  
Author(s):  
Wei Wu ◽  
Hailong Yin ◽  
Hao Zhang ◽  
Jia Kang ◽  
Yun Li ◽  
...  
Keyword(s):  
Corrosion Rate ◽  
Tensile Stress ◽  
Corrosion Behavior ◽  
Electrochemical Impedance ◽  
Pipeline Steel ◽  
Open Circuit ◽  
Co2 Corrosion ◽  
X80 Pipeline Steel ◽  
X80 Steel ◽  
Co2 Environment

An investigation into the electrochemical corrosion behavior of X80 pipeline steel under different elastic and plastic tensile stress in a CO2-saturated NaCl solution has been carried out by using open-circuit potential, potentiodynamic polarization, electrochemical impedance spectroscopy, and surface analysis techniques. The results show that the corrosion rate of X80 steel first increases and then slightly decreases with the increase of elastic tensile stress, whereas the corrosion rate sharply increases with the increase of plastic tensile stress. Both elastic and plastic tensile stress can enhance steel corrosion by improving the electrochemical activity of both anodic and cathodic reactions. Moreover, compared with elastic tensile stress, plastic tensile stress has a more significant effect. Furthermore, electrochemical reactions for CO2 corrosion and mechanoelectrochemical effect are used to reasonably explain the corrosion behavior of stressed X80 steel in CO2 environment.

Electrochemical Behaviors of Die-Cast Mg-4Al-0.4Mn-Xpr (x=0, 1, 4) Alloys in NaCl Solution

2013 ◽  
Vol 690-693 ◽  
pp. 82-88
Author(s):  
Xiao Dong Niu ◽  
Wei Sun ◽  
Xin Qiu ◽  
Jian Meng ◽  
Jian An
Keyword(s):  
Electrochemical Impedance ◽  
Electrochemical Corrosion ◽  
Open Circuit ◽  
Nacl Solution ◽  
Electrochemical Behaviors ◽  
Β Phase ◽  
Die Cast ◽  
Corrosion Behaviors ◽  
Potential Test

The microstructures and electrochemical corrosion behaviors of die-cast Mg-4Al-0.4Mn-xPr (x=0, 1, 4 wt.%) alloys have been investigated. Electrochemical behaviors of all alloys are described by open circuit potential test, potentiodynamic polarization test and electrochemical impedance spectroscope in 3.5 wt.% NaCl solution. The results show that the α-Mg grain is refined and the continuous net β phase appears gradually with increasing the content of Pr in the Mg-4Al-0.4Mn alloys. Moreover, the β phase plays a role of galvanic cathode in AM40 alloy and corrosion barrier in Pr-containing alloys, respectively. Electrochemical measurements show that Pr can improve corrosion resistance of Mg-4Al-0.4Mn alloy in the 3.5 wt.% NaCl solution, and corrosion rate decreases with increasing Pr content.

Influence of Composite Nano-Coating of Ni-Co-SiC Obtained by Electrodeposition on the Corrosion Resistance of API 5L X80 Steel

2017 ◽  
Vol 899 ◽  
pp. 317-322 ◽  
Author(s):  
Roseana Florentino da Costa Pereira ◽  
Edkarlla Sousa Dantas de Oliveira ◽  
Diogo Lins Alves e Silva ◽  
Andrêssa Souza Ribeiro ◽  
Oscar Olimpio de Araújo Filho ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Open Circuit Potential ◽  
Electrochemical Impedance ◽  
Open Circuit ◽  
Nano Particles ◽  
Micro Hardness ◽  
X Ray ◽  
Hardness Tests ◽  
Nano Coating ◽  
X80 Steel

Corrosion problems are frequent and occur in various sectors of industries, resulting consequences of economic order and serious accidents involving human lives and contaminating the environment. The electrodeposition is one of the most popular methods for preventing corrosion, where the Ni-Co metal matrix has been widely applied. The incorporation of SiC nano-particles in electrochemical baths produces nanocomposite coatings to synergistic properties with potential application in anti-corrosion protection. The objective of this work was to develop the Ni-Co-SiC nano-coating electrodeposited on API 5L X80 steel and evaluate the corrosion resistance. Open circuit potential (OCP), electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PP) measurements were performed in 3.5% NaCl solution. To correlate with corrosion behavior, scanning electron microscopy (SEM), energy-dispersive X-ray spectrum (EDXS) and Vickers micro-hardness tests on the nano-coating were performed.

scholarly journals A gateway for ion transport on gas bubbles pinned onto solids

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Veton Haziri ◽  
Tu Pham Tran Nha ◽  
Avni Berisha ◽  
Jean-François Boily
Keyword(s):  
Ion Transport ◽  
Metal Ion ◽  
Electrochemical Impedance ◽  
Gas Bubbles ◽  
Open Circuit ◽  
Double Layers ◽  
Water Geochemistry ◽  
Chemical Potentials ◽  
Pore Water Geochemistry ◽  
Electric Potentials

AbstractGas bubbles grown on solids are more than simple vehicles for gas transport. They are charged particles with surfaces populated with exchangeable ions. We here unveil a gateway for alkali metal ion transport between oxygen bubbles and semi-conducting (iron oxide) and conducting (gold) surfaces. This gateway was identified by electrochemical impedance spectroscopy using an ultramicroelectrode in direct contact with bubbles pinned onto these solid surfaces. We show that this gateway is naturally present at open circuit potentials, and that negative electric potentials applied through the solid enhance ion transport. In contrast, positive potentials or contact with an insulator (polytetrafluoroethylene) attenuates transport. We propose that this gateway is generated by overlapping electric double layers of bubbles and surfaces of contrasting (electro)chemical potentials. Knowledge of this ion transfer phenomenon is essential for understanding electric shielding and reaction overpotential caused by bubbles on catalysts. This has especially important ramifications for predicting processes including mineral flotation, microfluidics, pore water geochemistry, and fuel cell technology.

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

Materials ◽  
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.

Application of Electrochemical Techniques to Characterization of the Corrosion Behaviors of GW63 Alloys

2007 ◽  
Vol 546-549 ◽  
pp. 571-574
Author(s):  
Xing Wu Guo ◽  
Jian Wei Chang ◽  
Shang Ming He ◽  
Peng Huai Fu ◽  
Wen Jiang Ding
Keyword(s):  
Electrochemical Impedance ◽  
Electrochemical Techniques ◽  
Open Circuit ◽  
Cyclic Polarization ◽  
Time Curve ◽  
Completely Monotonic ◽  
Treatment Conditions ◽  
Impedance Variation ◽  
Corrosion Behaviors

The corrosion behavior of GW63 (Mg-6wt.%Gd-3wt.%Y-0.4wt.%Zr) alloys in 5% NaCl aqueous solution has been investigated by PARSTAT 2273 instrument. The Open Circuit Potential (ECORR) vs. time curve, cyclic polarization (Pitting Scans) curve and Electrochemical Impedance Spectroscopy (EIS) was measured for the GW63 alloys in as-cast and T6 heat treatment conditions. The EIS results indicated that the tendency of impedance variation for as-cast condition was monotonic decreasing, however, the tendency of variation for T6 condition was not completely monotonic but the total tendency was decreasing. The values of impedance of GW63 alloy at 0.1 Hz are about 103 ohm-cm2 for as-cast and T6 condition.

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