scholarly journals Corrosion of Carbon Steel in Artificial Geothermal Brine: Influence of Carbon Dioxide at 70 °C and 150 °C

Materials ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 3801 ◽  
Author(s):  
Gabriela Aristia ◽  
Le Quynh Hoa ◽  
Ralph Bäßler
Keyword(s):  
Carbon Dioxide ◽  
Carbon Steel ◽  
Temperature Effect ◽  
Electrochemical Impedance ◽  
Corrosion Products ◽  
Localized Corrosion ◽  
Corrosion Mechanism ◽  
Sem Images ◽  
Geothermal Brine ◽  
Corrosive Effect

This study focuses on the corrosion mechanism of carbon steel exposed to an artificial geothermal brine influenced by carbon dioxide (CO2) gas. The tested brine simulates a geothermal source in Sibayak, Indonesia, containing 1500 mg/L of Cl−, 20 mg/L of SO42−, and 15 mg/L of HCO3− with pH 4. To reveal the temperature effect on the corrosion behavior of carbon steel, exposure and electrochemical tests were carried out at 70 °C and 150 °C. Surface analysis of corroded specimens showed localized corrosion at both temperatures, despite the formation of corrosion products on the surface. After 7 days at 150 °C, SEM images showed the formation of an adherent, dense, and crystalline FeCO3 layer. Whereas at 70 °C, the corrosion products consisted of chukanovite (Fe2(OH)2CO3) and siderite (FeCO3), which are less dense and less protective than that at 150 °C. Control experiments under Ar-environment were used to investigate the corrosive effect of CO2. Free corrosion potential (Ecorr) and electrochemical impedance spectroscopy (EIS) confirm that at both temperatures, the corrosive effect of CO2 was more significant compared to that measured in the Ar-containing solution. In terms of temperature effect, carbon steel remained active at 70 °C, while at 150 °C, it became passive due to the FeCO3 formation. These results suggest that carbon steel is more susceptible to corrosion at the near ground surface of a geothermal well, whereas at a deeper well with a higher temperature, there is a possible risk of scaling (FeCO3 layer). A longer exposure test at 150 °C with a stagnant solution for 28 days, however, showed the unstable FeCO3 layer and therefore a deeper localized corrosion compared to that of seven-day exposed specimens.

scholarly journals Effect of Additional Sulfide and Thiosulfate on Corrosion of Q235 Carbon Steel in Alkaline Solutions

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Bian Li Quan ◽  
Jun Qi Li ◽  
Chao Yi Chen
Keyword(s):  
Carbon Steel ◽  
Photoelectron Spectroscopy ◽  
Steel Corrosion ◽  
Corrosion Products ◽  
Alkaline Solutions ◽  
Corrosion Mechanism ◽  
Surface Cracks ◽  
Weight Loss Method ◽  
Q235 Carbon Steel ◽  
Loss Method

This paper investigated the effect of additional sulfide and thiosulfate on Q235 carbon steel corrosion in alkaline solutions. Weight loss method, scanning electron microscopy (SEM) equipped with EDS, X-ray photoelectron spectroscopy (XPS), and electrochemical measurements were used in this study to show the corrosion behavior and electrochemistry of Q235 carbon steel. Results indicate that the synergistic corrosion rate of Q235 carbon steel in alkaline solution containing sulfide and thiosulfate is larger than that of sulfide and thiosulfate alone, which could be due to redox reaction of sulfide and thiosulfate. The surface cracks and pitting characteristics of the specimens after corrosion were carefully examined and the corrosion products film is flake grains and defective. The main corrosion products of specimen induced by S2−and S2O32-are FeS, FeS2, Fe3O4, and FeOOH. The present study shows that the corrosion mechanism of S2−and S2O32-is different for the corrosion of Q235 carbon steel.

Effect of the Fe/Cu Relationship Corrosion and low Alloying Elements on Corrosion Behavior of Cast Aluminum Parts

2016 ◽  
Vol 1815 ◽  
Author(s):  
C. Rodríguez-Rivera ◽  
J.A. García-Hinojosa ◽  
F.J. Rodríguez-Gómez
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Aluminum Alloys ◽  
Impedance Spectroscopy ◽  
Corrosion Rate ◽  
Open Circuit Potential ◽  
Electrochemical Impedance ◽  
Open Circuit ◽  
Localized Corrosion ◽  
Corrosion Mechanism ◽  
Corrosion Morphology

ABSTRACTThe aim of this study is to compare the corrosion rate of aluminum alloys for ornamental pieces. Three Fe/Cu relationships were tested in order to improve hardness and brightness in aluminum pieces since these alloys are used in the making of ornamental pieces. The variation on Fe/Cu content could result in modification on corrosion rate, since a metallographic characterization must be carried out identifying the presence of intermetallic phases. The presence of these elements could result in increasing corrosion rate, or even in modification of corrosion morphology, so localized corrosion could be expected.The assessment of corrosion rate was carried out in saline media, since chlorides are ions that promote localized corrosion. Electrochemical techniques (polarization curves and Tafel plots) were used in order to evaluate the attack in aluminum pieces; electrochemical impedance spectroscopy was also employed with voltage amplitude of 10 mV rms, and a frequency range from 10,000 Hz to 0.01 Hz. A typical three electrodes cell was used, exposing an area of one cm2. Before polarization, open circuit potential was monitored for an hour looking for a steady state. All conditions were tested for triplicate.The behavior of open circuit potential vs. time, and polarization curves was analyzed; a corrosion mechanism is proposed according to the electrochemical control. Polarization rate was calculated by using Tafel plots and, an electrochemical impedance spectroscopy analysis by using equivalent electric circuits is shown. Electrochemical impedance will yield information about corrosion morphology that is backed with microscopic inspection.The objective of this study is to compare the corrosion rate of aluminum alloys for ornamental pieces in order to determine the effect of the relationship Fe/Cu on the corrosion mechanism in aluminum parts for ornamental pieces.

scholarly journals Study on corrosion behavior of X80 steel under stripping coating by sulfate reducing bacteria

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Yan-Yu Cui ◽  
Yong-Xiang Qin ◽  
Qing-Miao Ding ◽  
Yu-Ning Gao
Keyword(s):  
Corrosion Behavior ◽  
Electrochemical Impedance ◽  
Sulfate Reducing Bacteria ◽  
Fluorescent Labeling ◽  
Corrosion Products ◽  
Economic Losses ◽  
Corrosion Mechanism ◽  
Sulfate Reducing ◽  
X80 Steel ◽  
Reducing Bacteria

Abstract Background At present, microorganism has been considered as important factors that threaten to buried pipelines with disbonded coatings. Aiming at the problem of unknown corrosion mechanism of sulfate-reducing bacteria (SRB), a series of studies have been carried out in this paper. Spectrophotometer and fluorescent labeling technology are used to study the growth and attachment of SRB in the simulated soil solution. The corrosion behavior of X80 pipeline steel with or without SRB was researched by electrochemical methods such as open circuit potential, dynamic potential polarization curve, and electrochemical impedance spectroscopy. The microscopic morphology of the corrosion products on the surface was observed with a scanning electron microscope (SEM), and the element content of the corrosion products on the surface of the sample after corrosion was observed using X-ray energy spectrum (EDS) analysis. Results The results showed that the growth and reproduction of SRB caused the pH of the soil simulated solution to increase, which may promote the corrosion of X80 steel. In addition, the cathode reaction of X80 steel in a sterile environment is the reduction of H+, and the main corrosion product is iron oxide. When the soil simulation solution contains SRB, the cathodic reaction is controlled by both H+ reduction and sulfide depolarization reactions, and FeS appears in the corrosion products. Conclusion Although the life cycle of SRB is only about 14 days, the corrosion of X80 steel is greatly promoted by SRB, and even causes corrosion perforation, which will bring huge economic losses and serious safety hazards.

scholarly journals Universalism of inhibitors against hydrogen sulfide and carbon dioxide corrosion of carbon steel

2021 ◽  
Vol 225 ◽  
pp. 05001
Author(s):  
Vladimir Vigdorovich ◽  
Liudmila Tsygankova ◽  
Natalia Shel ◽  
Nedal Alshikha
Keyword(s):  
Carbon Dioxide ◽  
Hydrogen Sulfide ◽  
Carbon Steel ◽  
Hydrogen Diffusion ◽  
Electrochemical Impedance ◽  
Negative Impact ◽  
Sulfate Reducing Bacteria ◽  
Carbon Dioxide Corrosion ◽  
Sulfate Reducing ◽  
Reducing Bacteria

The universality of inhibitors is understood as their ability to inhibit several types of corrosion attack: hydrogen sulfide and carbon dioxide corrosion, hydrogen diffusion into metal, development of sulfate-reducing and other types of bacteria, negative impact on the mechanical properties of metals. Indicators of universalism of new inhibitor have been studied. Producer of the inhibiting compositions is Limited Liability Company «INCORGAZ» (S-Petersburg, Russia). The efficacy of the inhibitor in the concentration of 25 - 200 mg/L has been studied with respect to carbon steel in a highly mineralized chloride medium (pH= 6) and NACE medium (5 g/L NaCl, 0.25 g/L CH3COOH, pH =3.5) containing H2S (50-400 mg/L) and CO2 (1at) separately and together. The bactericidal properties of the inhibitor were studied with respect to sulfate-reducing bacteria in the Postgate medium. The investigations were carried out by the methods of linear polarization resistance, electrochemical impedance spectroscopy, gravimetry, potentiodynamic polarization. The protective effectiveness of the inhibitor reaches 80% in the presence of CO2 and 90% in hydrogen sulphide environments. The inhibitor repeatedly reduces the number of sulfate-reducing bacteria and the production of biogenic hydrogen sulfide and inhibits the diffusion of hydrogen into steel.

Corrosion behavior of carbon steel in H2S-CO2-H2O-methyldiethanolamine (MDEA) solution under the presence of chloride ions

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Guiyang Wu ◽  
Xikui Gu ◽  
Wanwei Zhao ◽  
Rui Fan ◽  
Ting Mao
Keyword(s):  
High Temperature ◽  
Carbon Steel ◽  
Low Temperature ◽  
Corrosion Rate ◽  
Corrosion Behavior ◽  
Electrochemical Impedance ◽  
Chloride Ion ◽  
Chloride Ions ◽  
Corrosion Products ◽  
Content Type

Purpose This paper aims to study the effect of chloride ions concentration on the corrosion behavior of carbon steel in methyldiethanolamine (MDEA) aqueous solution in the sight of different process parameters of purification plant. Design/methodology/approach Due to the decrease of filtration efficiency and separation efficiency, the chloride ion in the desulfurization solution is enriched. The corrosion behavior of carbon steel under chloride ion enrichment environment was studied by weight-loss method, electrochemical impedance spectroscopy, cyclic polarization curve, X-ray photoelectron spectroscopy and scanning electron microscopy. Findings The results show that temperature and hydrogen sulfide loads are the main factors of corrosion in CO2-MDEA-H2O-H2S environment. The enrichment of chloride ions reduces the corrosion rate at low temperature but promotes the corrosion rate at high temperature. The chloride concentration should be controlled below 3000 mg/L, and no pitting corrosion was found under the experimental conditions. Originality/value The effect of chloride ion enrichment on MDEA solution corrosion shows that at low temperature, the increase of chloride ion will reduce the acid gas load and increase the density of corrosion products, so as to reduce the corrosion; on the contrary, at high temperature, the density of corrosion products will decrease and the corrosion will be intensified as well. It is believed that the chloride ion should be controlled below 3000 mg/L according to the results of the tests.

Corrosion Products and Surface Morphology for Coated, Uncoated, and Insulated A333 Steel Pipelines in Marine Harsh Environment

2021 ◽  
Author(s):  
Alan Hillier ◽  
Faisal Khan ◽  
Susan Caines
Keyword(s):  
Microbial Reduction ◽  
Corrosion Products ◽  
Localized Corrosion ◽  
Harsh Environment ◽  
X Ray Diffraction ◽  
Sem Images ◽  
Pipe Surface ◽  
Cold Environments ◽  
Magnetite Fe3o4 ◽  
Full Scale Tests

Abstract In situ studies with CUI and corrosion under coating is rare, especially for full scale tests in marine harsh environment. A333 low temperature carbon steel is selected for its versatile use in cold environments. This material is not widely studied in marine environment. Therefore, this work reports corrosion type, products, morphology and mechanism for thirty-six model pipelines (insulated, uninsulated, coated and uncoated) placed at Argentia, NL. Corrosion products were identified using x-ray diffraction (XRD). The detection and semi-quantification of elements on pipe surfaces was performed using energy disruptive spectroscopy (EDS) which was coupled to a scanning electron microscope (SEM). SEM images confirmed the formation of characteristic morphological structures such as sandy crystal (lepidocrocite γ-FeOOH), cotton ball (goethite α-FeOOH), and small grain (akageneite β-FeOOH) structures. For insulated uncoated pipes, the main phases were goethite, akageneite, and hematite(α-Fe2O3). For uncoated uninsulated pipes, akageneite, goethite, and hematite were detected as main phases. For coated pipes, goethite was the main phase. When ferrihydrite was detected with akageneite, there was less lepidocrocite and goethite than when ferrihydrite was not present. Uncoated pipes had deepest pits and highest corrosion rates as previously reported in [1]. Magnetite (Fe3O4) was present in these samples only in year two. Magnetite is a passive oxide formed on the iron surface but can also be a product of microbial reduction of ferrihydrite in certain conditions. A proposed mechanism for the high corrosion rate and pits in uncoated pipes is due to the increased localized corrosion from akageneite due to excess chloride and moisture from seawater spray as well as stabilized ferrihydrite limiting goethite formation, thus reducing steel pipe surface passivity.

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 AC Corrosion of Carbon Steel under Cathodic Protection Condition: Assessment, Criteria and Mechanism. A Review

Materials ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2158
Author(s):  
Andrea Brenna ◽  
Silvia Beretta ◽  
Marco Ormellese
Keyword(s):  
Carbon Steel ◽  
Cathodic Protection ◽  
Grey Literature ◽  
Reference Electrode ◽  
Steel Structures ◽  
Localized Corrosion ◽  
Corrosion Mechanism ◽  
Narrative Literature Review ◽  
Protection Potential ◽  
Ac Interference

Cathodic protection (CP), in combination with an insulating coating, is a preventative system to control corrosion of buried carbon steel pipes. The corrosion protection of coating defects is achieved by means of a cathodic polarization below the protection potential, namely −0.85 V vs. CSE (CSE, copper-copper sulfate reference electrode) for carbon steel in aerated soil. The presence of alternating current (AC) interference, induced by high-voltage power lines (HVPL) or AC-electrified railways, may represent a corrosion threat for coated carbon steel structures, although the potential protection criterion is matched. Nowadays, the protection criteria in the presence of AC, as well as AC corrosion mechanisms in CP condition, are still controversial and discussed. This paper deals with a narrative literature review, which includes selected journal articles, conference proceedings and grey literature, on the assessment, acceptable criteria and corrosion mechanism of carbon steel structures in CP condition with AC interference. The study shows that the assessment of AC corrosion likelihood should be based on the measurement of AC and DC (direct current) related parameters, namely AC voltage, AC and DC densities and potential measurements. Threshold values of the mentioned parameters are discussed. Overprotection (EIR-free < −1.2 V vs. CSE) is the most dangerous condition in the presence of AC: the combination of strong alkalization close to the coating defect due to the high CP current density and the action of AC interference provokes localized corrosion of carbon steel.

scholarly journals Study on Corrosion Behavior of X80 Steel under Stripping Coating by Sulfate Reducing Bacteria

2020 ◽  
Author(s):  
Yanyu Cui ◽  
Yongxiang Qin ◽  
Qingmiao Ding ◽  
Yuning Gao
Keyword(s):  
Electrochemical Impedance ◽  
Pipeline Steel ◽  
Sulfate Reducing Bacteria ◽  
Fluorescent Labeling ◽  
Corrosion Products ◽  
Economic Losses ◽  
Corrosion Mechanism ◽  
Sulfate Reducing ◽  
X80 Steel ◽  
Reducing Bacteria

Abstract Background: At present, microorganism has been considered as important factors that threaten to buried pipelines with disbonded coatings. Aiming at the problem of unknown corrosion mechanism of sulfate-reducing bacteria (SRB), a series of studies have been carried out in this paper. Spectrophotometer and fluorescent labeling technology are used to study the growth and attachment of SRB in the simulated soil solution. The electrochemical behavior of X80 pipeline steel with or without SRB was researched by electrochemical methods such as open circuit potential, dynamic potential polarization curve, and electrochemical impedance spectroscopy. The microscopic morphology of the corrosion products on the surface of the sample was observed with a scanning electron microscope (SEM), and the element content of the corrosion products on the surface of the sample after corrosion was observed using X-ray energy spectrum (EDS) analysis. Results: The results showed that the growth and reproduction of SRB caused the pH of the soil simulated solution to increase, which promoted the corrosion of X80 steel. In addition, the cathode reaction of X80 steel in a sterile environment is the reduction of H+, and the main corrosion product is Fe oxides. When the soil simulation solution contains SRB, the cathodic reaction is controlled by both H+ reduction and sulfide depolarization reactions, and FeS appears in the corrosion products. Conclusion: Although the life cycle of SRB is only about 14 days, the corrosion of X80 steel is greatly promoted by SRB, and even causes corrosion perforation, which will bring huge economic losses and serious safety hazards.

scholarly journals Effect of CO2 Partial Pressure on the Corrosion Behavior of J55 Carbon Steel in 30% Crude Oil/Brine Mixture

Materials ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 1765 ◽  
Author(s):  
Haitao Bai ◽  
Yongqing Wang ◽  
Yun Ma ◽  
Qingbo Zhang ◽  
Ningsheng Zhang
Keyword(s):  
Carbon Steel ◽  
Corrosion Rate ◽  
Crude Oil ◽  
Partial Pressure ◽  
Initial Period ◽  
Localized Corrosion ◽  
Corrosion Mechanism ◽  
Corrosion Properties ◽  
Co2 Partial Pressure ◽  
Corrosion Scale

The influence of CO2 partial pressure on the corrosion properties, including corrosion rate, morphology, chemical composition, and corrosion depth, of J55 carbon steel in 30% crude oil/brine at 65 °C was investigated. A corrosion mechanism was then proposed based on the understanding of the formation of localized corrosion. Results showed that localized corrosion occurred in 30% crude oil/brine with CO2. The corrosion rate sharply increased as the CO2 partial pressure (P co 2 ) was increased from 0 to 1.5 MPa, decreased from P co 2 = 1.5 MPa to P co 2 = 5.0 MPa, increased again at P co 2 = 5.0 MPa, and then reached a constant value after P co 2 = 9.0 MPa. The system pH initially decreased, rapidly increased, and then stabilized as CO2 partial pressure was increased. In the initial period, the surface of J55 carbon steel in the CO2/30% crude oil/brine mixtures showed intense corrosion. In conclusion, CO2 partial pressure affects the protection performance of FeCO3 by changing the formation of corrosion scale and further affecting the corrosion rate.

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