scholarly journals Real-Time Corrosion Monitoring of AISI 1010 Carbon Steel with Metal Surface Mapping in Sulfolane

Materials ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3276 ◽  
Author(s):  
Bak ◽  
Losiewicz ◽  
Kozik ◽  
Kubisztal ◽  
Dybal ◽  
...  
Keyword(s):  
Carbon Steel ◽  
Comprehensive Evaluation ◽  
Potential Method ◽  
Open Circuit ◽  
Localized Corrosion ◽  
Electrochemical Technique ◽  
Corrosion Monitoring ◽  
Kelvin Probe ◽  
Surface Mapping ◽  
Subsequent Formation

Solvents are widely used in organic synthesis. Sulfolane is a five-membered heterocyclic organosulfur sulfone (R-SO2-R’, where R/R’ is alkyl, alkenyl, or aryl) and an anthropogenic medium commonly used as industrial extractive solvent in the liquid-liquid and liquid-vapor extraction processes. Under standard conditions sulfolane is not aggressive towards steel, but at higher temperatures and in oxygen, water, or chlorides presence, it can be decomposed into some corrosive (by-)products with generation of SO2 and subsequent formation of corrosive H2SO3. This pilot-case study provides data from laboratory measurements performed in low conductivity sulfolane-based fluids using an industrial multi-electrochemical technique for reliable detection of corrosion processes. In particular, a comprehensive evaluation of the aqueous phase impact on general and localized corrosion of AISI 1010 carbon steel in sulfolane is presented. Assessment of corrosive damage was carried out using an open circuit potential method, potentiodynamic polarization curves, SEM/EDS and scanning Kelvin probe technique. It was found that an increase in the water content (1–3 vol.%) in sulfolane causes a decrease in the corrosion resistance of AISI 1010 carbon steel on both uniform and pitting corrosion due to higher conductance of the sulfolane-based fluids.

scholarly journals Mechanical Properties, Corrosion Resistance and Bioactivity of Oxide Layers Formed by Isothermal Oxidation of Ti-6Al-7Nb Alloy

Coatings ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 505
Author(s):  
Krzysztof Aniołek ◽  
Bożena Łosiewicz ◽  
Julian Kubisztal ◽  
Patrycja Osak ◽  
Agnieszka Stróż ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Corrosion Resistance ◽  
Contact Potential Difference ◽  
Isothermal Oxidation ◽  
Potential Method ◽  
Open Circuit ◽  
Kelvin Probe ◽  
Contact Potential ◽  
Oxide Layers

Titanium and its alloys are among the most promising biomaterials for medical applications. In this work, the isothermal oxidation of Ti-6Al-7Nb biomedical alloy towards improving its mechanical properties, corrosion resistance, and bioactivity has been developed. The oxide layers were formed at 600, 700, and 800 °C for 72 h. Scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), 3D profilometry, and microindentation test, were used to characterize microstructure, surface geometrical structure, and the hardness of the diphase (α + β) Ti-6Al-7Nb alloy after oxidation, respectively. In vitro corrosion resistance tests were carried out in a saline solution at 37 °C using the open-circuit potential method and potentiodynamic measurements. Electronic properties in the air were studied using the Scanning Kelvin Probe (SKP) technique. The bioactivity test was conducted by soaking the alkali- and heat-treated samples in simulated body fluid for 7 days. The presence of apatite was confirmed using SEM/EDS and Fourier Transform Infrared Spectroscopy (FTIR) studies. The thickness of oxide layers formed increased with the temperature growth from 0.25 to 5.48 µm. It was found that with increasing isothermal oxidation temperature, the surface roughness, hardness, corrosion resistance, and contact potential difference increased. The Ti-6Al-7Nb alloy after oxidation revealed the HAp-forming ability in a biological environment.

scholarly journals In-Situ Monitoring and Analysis of the Pitting Corrosion of Carbon Steel by Acoustic Emission

2019 ◽  
Vol 9 (4) ◽  
pp. 706 ◽  
Author(s):  
Junlei Tang ◽  
Junyang Li ◽  
Hu Wang ◽  
Yingying Wang ◽  
Geng Chen
Keyword(s):  
Acoustic Emission ◽  
Carbon Steel ◽  
Pitting Corrosion ◽  
Optical Microscope ◽  
Open Circuit ◽  
In Situ Monitoring ◽  
Localized Corrosion ◽  
Uniform Corrosion ◽  
Corrosion Morphology

The acoustic emission (AE) technique was applied to monitor the pitting corrosion of carbon steel in NaHCO3 + NaCl solutions. The open circuit potential (OCP) measurement and corrosion morphology in-situ capturing using an optical microscope were conducted during AE monitoring. The corrosion micromorphology was characterized with a scanning electron microscope (SEM). The propagation behavior and AE features of natural pitting on carbon steel were investigated. After completion of the signal processing, including pre-treatment, shape preserving interpolation, and denoising, for raw AE waveforms, three types of AE signals were classified in the correlation diagrams of the new waveform parameters. Finally, a 2D pattern recognition method was established to calculate the similarity of different continuous AE graphics, which is quite effective to distinguish the localized corrosion from uniform corrosion.

Scanning Kelvin Probe Microscopy Study of Mg-Zn-Ca Alloys

2017 ◽  
Author(s):  
Svitlana Fialkova ◽  
Zhigang Xu ◽  
Devdas Pai ◽  
Jagannathan Sankar
Keyword(s):  
Potential Distribution ◽  
Chemical Properties ◽  
Open Circuit ◽  
Alloying Elements ◽  
Localized Corrosion ◽  
Kelvin Probe ◽  
Protective Oxide ◽  
Corrosive Media ◽  
Atomic Force ◽  
Scanning Kelvin Probe

This study focused on understanding the interactions between alloying elements in a magnesium (Mg) matrix and the effect of the alloying elements on corrosion behavior of Mg-alloys. The development of atomic force microscope (AFM) techniques has enabled the evaluation of physical and chemical properties of surfaces at the sub-micron level. Scanning Kelvin probe force microscopy (SKPFM) is particularly useful for studying localized corrosion phenomena of alloys. SKPFM generates a map of the potential distribution across a sample with a resolution of probe tip radius, nowadays ranging from 5 to 30 nm. Furthermore, the open circuit potential of various pure metals in solution is linearly related to the Volta potential value measured in air immediately after exposure to corrosive media. SKPFM is a useful tool to practically assess the nobility of a surface. This technique has been applied to the heterogeneous microstructure of Mg-Zn-Ca-RE (RE = Zr, Nd, Ga) alloys and provided clear evidence regarding the shape, position, compositional inhomogeneities and local practical nobility of intermetallic particles. Correlation between the measured potential distribution and the reactivity of these particles has been shown. Atomic force lithography (AFL, scratching with the hard tip) is a controlled method for local disruption of the protective oxide film that naturally formed on an Mg-surface in air. Combining SKPFM and AFL, the stability of the passive film and the tendency for stabilization of localized corrosion can be monitored. In addition, the lateral imaging capabilities of the AFM provide an approach to study the role of different microstructural features such as grain boundaries and impurities in the process of inducing localized corrosion.

Corrosion study of low carbon steel under simulated geological disposal environments for HLW in China

2020 ◽  
Author(s):  
Junhua Dong
Keyword(s):  
Carbon Steel ◽  
Corrosion Rate ◽  
Dissolved Oxygen ◽  
Open Circuit Potential ◽  
Steel Substrate ◽  
Low Carbon Steel ◽  
Open Circuit ◽  
Localized Corrosion ◽  
Low Carbon ◽  
Simulated Groundwater

<p>In the multi-barrier system of HLW repository, overpack is the first barrier to isolate high-level radioactive nuclides from biosphere, and Low carbon steel has been considered to be a promising candidate material for manufacturing the oberpack due to its good mechanical performance and workability and weldability. However, during thousands of years of geological disposal, the corrosion resistance of low carbon steel and its corrosion evolution behavior are the first element that must be fully understood, because it determines the life cycle of the artificial barrier.</p><p>Conventional studies had suggested that the corrosion of low carbon steel under the deep geological environment was driven by hydrogen evolution reaction (HER) based on that the dissolved oxygen was completely depleted during the long term disposal. However, the residual oxygen content is a critical factor to determine the corrosion mode of cathodic reduction reaction. Thermodynamics data indicated that the initial ferrous corrosion products formed in the deaerated bicarbonate solution can be chemically oxidized into ferric substance by the trace content of dissolved oxygen, and the accumulated FeOOH as a cathodic depolarizer significantly increased the open circuit potential and enhanced the corrosion rate of the low carbon steel. Moreover, chloride and sulfate in the simulated groundwater can reduce the increase of open circuit potential but it still promotes the corrosion of the low carbon steel. As the environments contained aggressive anions and high concentration of dissolved oxygen, low carbon steel was prone to suffer from the localized corrosion and the corrosion rate was obviously increased. By alloying with some contents of Ni and Cu, the corrosion rate of low alloy steel was decreased by an order of magnitude and it was less prone to suffer from the localized corrosion.</p><p>Under the conditions of simulated groundwater with different content of GMZ bentonite，the bentonite colloidal particle layer attached to the surface of low carbon steel showed blocking effect on resisting oxygen diffusion to the steel substrate, which consequently decrease the further oxidation of ferrous to ferric substances and the corrosion rate of low carbon steel. However, the barrier performance of bentonite colloids would be deteriorated due to their coagulation caused by the ferrous ions dissolved from the steel substrate. High content of bentonite was beneficial to maintain and to prolong the stabilization of the barrier system. An equivalent circuit model which correlates with the interfacial structure between electrode substrate and rust and bentonite layer was proposed. The fitting results showed a very good match between the model and experimental data, and the evolution of the results was also in agreement with real changes.</p>

scholarly journals In-Situ Monitoring and Analyzing Pitting Corrosion of Carbon Steel by Acoustic Emission

2018 ◽  
Author(s):  
Junlei Tang ◽  
Junyang Li ◽  
Hu Wang ◽  
Yingying Wang ◽  
Geng Chen
Keyword(s):  
Acoustic Emission ◽  
Carbon Steel ◽  
Pitting Corrosion ◽  
Optical Microscope ◽  
Open Circuit ◽  
In Situ Monitoring ◽  
Localized Corrosion ◽  
Uniform Corrosion ◽  
Corrosion Morphology

The acoustic emission (AE) technique was applied to monitor the pitting corrosion of carbon steel in NaHCO3 + NaCl solutions. The open circuit potential (OCP) measurement and the corrosion morphology in-situ capturing using optical microscope were conducted during AE monitoring. The corrosion micromorphology was characterized with scanning electron microscope (SEM). The propagation behavior and AE features of natural pitting on carbon steel were investigated. After the performing of signal processing including pre-treatment, shape preserving interpolation and denoising for raw AE waveforms, three types of AE signals can be classified in the correlation diagrams of new waveform parameters. Finally, a 2D pattern recognition method was established to calculate the similarity of different continuous AE graphics, which is quite effective to distinguish the localized corrosion from uniform corrosion.

An Inhibitive Effect of Aeration on the Pitting Corrosion of Steels in Ethanolic Environments

CORROSION ◽  
10.5006/4000 ◽  
2021 ◽  
Author(s):  
Ali Ashrafriahi ◽  
Anatolie Carcea ◽  
Roger Newman
Keyword(s):  
Carbon Steel ◽  
Pitting Corrosion ◽  
Surface Film ◽  
Steel Corrosion ◽  
Open Circuit ◽  
Localized Corrosion ◽  
Potential Measurement ◽  
Pitting Corrosion Resistance ◽  
Cyclic Potentiodynamic Polarization ◽  
Passivation Potential

This work is aimed at improving the understanding of the localized corrosion of carbon steel in ethanolic solutions. The role of ethanol dehydration, chloride, and oxygen level in the pitting behaviour of carbon steel in ethanolic environments in the presence of supporting electrolytes was investigated. Open Circuit Potential measurement, Cyclic Potentiodynamic Polarization and Potentiostatic testing were conducted on specimens exposed to ethanolic environments prepared from pure dehydrated ethanol to study the pitting behaviour of carbon steel. Corrosion and passivation potentials significantly reduce due to the change in the cathodic reaction and the decrease in passivation kinetics under de-aerated conditions. SEM and EDX examination indicated that no pitting corrosion is observed without chlorides, and chloride significantly destabilizes the surface film resulting in decreases of both corrosion potential and passivation potential. A decrease in the dissolved oxygen in the solution reduces but does not eliminate the pitting susceptibility. Iron oxide is identified as the significant corrosion product at different water and oxygen content. Therefore, ethanol aeration can be a proper method to increase pitting corrosion resistance in ethanolic solutions.

The Effects of Chloride, Nitrate, and Nitrite on the Localized Corrosion of Carbon Steel in Simulated Concrete Pore Solutions

CORROSION ◽  
10.5006/3667 ◽  
2021 ◽  
Author(s):  
Chenxi Liu ◽  
Narasi Sridhar
Keyword(s):  
Carbon Steel ◽  
Electrochemical Impedance ◽  
Open Circuit ◽  
Localized Corrosion ◽  
Reinforcing Bars ◽  
Electrochemical Parameters ◽  
Cyclic Potentiodynamic Polarization ◽  
Burman Design ◽  
The Difference ◽  
Nitrate And Nitrite

Localized corrosion is a precursor to the deterioration of carbon steel reinforcing bars in concrete. The localized corrosion of carbon steel in simulated concrete pore solutions was investigated by cyclic potentiodynamic polarization (CPP) technique. A four-factor, two-level, full factorial design and a five-factor, two-level, Plackett-Burman design were used to study the effects of OH-, Cl-, NO3-, NO2-, with Na+ and Ca2+ cations on the localized corrosion of carbon steel. The results show that the occurrence of localized corrosion can be evaluated by the type of CPP curves (negative, mixed or positive hysteresis) and the difference between the open circuit and repassivation potentials (OCP- Erp). The lowest (OCP- Erp), indicating a low risk of pitting corrosion, could be obtained with high OH-, high NO2-, and low Cl-, whereas the effect of NO3- was not significant. The corrosion activities near the OCP were measured using Linear Polarization Resistance (LPR) and Electrochemical Impedance Spectroscopy (EIS) methods. They indicated that NO2- and Cl- were the main factors influencing the corrosion rate. The cationic species did not have a significant influence on the electrochemical parameters.

scholarly journals The Study of Corrosion Behaviors of Carbon Steel Weldments and Their Inhibition in Simulated Pore Solution Using Multi-Electrode Array Technique

2021 ◽  
Vol 11 (18) ◽  
pp. 8278
Author(s):  
Lujia Yang ◽  
Zhenping Ma ◽  
Yufeng Zheng ◽  
Xiaona Wang ◽  
Yi Huang ◽  
...  
Keyword(s):  
Carbon Steel ◽  
Pore Solution ◽  
Galvanic Corrosion ◽  
Electrode Array ◽  
Open Circuit ◽  
Localized Corrosion ◽  
Galvanic Current ◽  
Corrosion Behaviors ◽  
Weld Area ◽  
Multi Electrode Array

A multi-electrode array sensor was developed to study the corrosion behaviors of carbon steel weldments and the effectiveness of the NaNO2 inhibitor in carbonated pore solution. The sensor can simulate a complete weldment, and the measurement results can match well with the coupon immersion test. The galvanic corrosion between the weld area, heat-affected area, and base metal area, as well as the effect of nitrite corrosion inhibitor on the weld area, were observed by measuring the open circuit potential, coupling potential, and galvanic current. The results show that corrosion is likely to happen around the weld metal area and its adjacent heat-affected zone. The intensive galvanic currents can accelerate the localized corrosion, while NaNO2 can inhibit it.

Microbiologically Induced Corrosion Monitoring Using Open-Circuit Potential (OCP) Measurements

2015 ◽  
Vol 227 ◽  
pp. 294-297 ◽  
Author(s):  
Rosilawati Mohd Rasol ◽  
Akrima Abu Bakar ◽  
Norhazilan Md Noor ◽  
Yahaya Nordin ◽  
Mardhiah Ismail
Keyword(s):  
Carbon Steel ◽  
Open Circuit Potential ◽  
Corrosion Potential ◽  
Control Sample ◽  
Desulfovibrio Desulfuricans ◽  
Open Circuit ◽  
Metal Loss ◽  
Desulfovibrio Vulgaris ◽  
Corrosion Monitoring ◽  
Microbiologically Induced Corrosion

This study investigates how sulfate-reducing bacteria (SRB) influence the process of microbiologically induced corrosion (MIC) of carbon steel by measuring corrosion potential using open-circuit potential (OCP) measurements. MIC is mainly influenced byDesulfovibrio vulgaris, formerly known asDesulfovibrio desulfuricans subsp. Desulfuricans, deposited asspirillum desulfuricans, which produces D(-)-lactate dehydrogenase. This strain was recommended by ATCC to be used in the tests described in ASTM. A pure colony of SRB was isolated from the Baram and Sungai Ular areas in Malaysia. An evaluation of SRB growth was performed during the test in the inoculated medium anaerobically at 37 ̊. The results showed that the corrosion potentialEocincreases in the presence of SRB in pure and mixed cultures as compared to the control sample. These results indicate that the SRB caused the metal loss on the carbon steel surface through direct corrosive action of the H2S generated by the bacteria during their metabolic process of reducing sulfates to the sulfide form.

scholarly journals Title Synergistic Effect of Al2O3 Inclusion and Pearlite on the Localized Corrosion Evolution Process of Carbon Steel in Marine Environment

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2277 ◽  
Author(s):  
Chao Liu ◽  
Xuequn Cheng ◽  
Zeyu Dai ◽  
Ryan Liu ◽  
Ziyu Li ◽  
...  
Keyword(s):  
Carbon Steel ◽  
Synergistic Effect ◽  
Oxygen Concentration ◽  
Marine Environment ◽  
Localized Corrosion ◽  
Kelvin Probe ◽  
Concentration Cell ◽  
Corrosion Morphology ◽  
Xisha Island ◽  
Al2o3 Inclusion

The initiation and evolution of the localized corrosion in carbon steel were investigated in a simulated marine environment of Xisha Island in the South China Sea. In the initial stage, localized corrosion occurred in the form of corrosion spot. The localized corrosion morphology and electrochemical information during corrosion process were tracked by field emission scanning electron microscopy energy dispersive spectrometry (FE-SEM-EDS), scanning vibrating electrode technique (SVET) and scanning Kelvin probe force microscopy (SKPFM). Localized corrosion was induced by the microcrevices around Al2O3 inclusions. The occluded cells and oxygen concentration cell formed in the pits could accelerate the localized corrosion. Pearlite accelerated the dissolution of the inside and surrounding ferrite via the galvanic effect between Fe3C and ferrite. Overall, the localized corrosion was initiated and evaluated under a synergistic effect of crevice corrosion, occluded cells, oxygen concentration cell and the galvanic couple between FeC3 and ferrite.

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