Bio Corrosion and Microbial Protection of Carbon Steel: Integrating Lawsonia inermis L Extract into Styrene-Acrylic Paints

Localized corrosion of carbon steel pipelines in oilfield environments is a serious concern. In environments containing both CO2 and H2S gases, pitting corrosion of carbon steel is considered to be a common occurrence which is particularly complex and still not fully understood. This paper presents a parametric study investigating the pitting corrosion behavior of carbon steel in CO2-H2S-containing environments. The work presented is divided into two parts. Part one focuses on understanding the impact of changes in three key process parameters (namely: temperature, absence/presence of 10% H2S, and absence/presence of CO2 in the gas phase) on FeS film formation process and overall the corrosion behavior of carbon steel with emphasis on general corrosion of carbon steel in a 3.5 wt% NaCl brine at 30°C and 80°C. Part two focuses on understanding the early and later stages of the pitting corrosion process, with consideration afforded to general corrosion and iron sulfide (FeS) film formation mechanisms, kinetics, and characteristics. The experiments were conducted based on short-term (7 h) and long-term tests (168 h) to investigate the early and later stages of evolution of pitting corrosion. Corrosion film properties and morphology are studied through a combination of electrochemical and surface analysis techniques which include scanning electron microscopy and x-ray diffraction. The extent of corrosion damage of the carbon steel is evaluated through the implementation of surface interferometry to study pit depth and geometry. The results show that early stages of pitting corrosion are more likely to occur with the formation of mackinawite at both 30°C and 80°C in H2S systems than in CO2 systems after 7 h. However, at 80°C extensive uniform corrosion is dominant, leading to the competing effect of iron sulfide (FeS) formation, continuous evolution of pitting corrosion, and continuous ferrite dissolution in the presence of CO2. Results from 168 h tests showed a buildup of FeS on the corroding steel surface with time with the increase in temperature and presence of CO2 in the gas phase. The buildup of FeS in H2S-CO2-containing environments is enhanced by ferrite dissolution. The FeS formed after 168 h is composed mainly of mackinawite at 30°C, and mackinawite and pyrrhotite at 80°C after 168 h. The combination of mackinawite (with a different morphology) and pyrrhotite is shown to promote more pitting and localized corrosion at 80°C than for mackinawite alone at 30°C.

Corrosion of carbon steel is investigated in the presence of Synechococcus sp. (S. sp., an aerogenic strain) with or without the coexistence of Pseudoalteromonas sp. (P. sp., an aerobic strain). Results of electrochemical and weight loss measurements suggest that the corrosion of carbon steel is continuous in S. sp. containing media while it is inhibited initially and accelerated finally in the coexistence of S. sp. and P. sp. This variation in corrosion rate is believed to be closely related to the difference in the growth and metabolism of two strains in different media. In media containing S. sp. alone, the slow reproduction of S. sp. leads to the relatively stable dissolved oxygen (DO) concentration and the continuous corrosion. In the case of S. sp. + P. sp., P. sp. consume DO and form protective biofilm at the initial stage, and then the death of P. sp. and the rapid reproduction of S. sp. cause the increase of DO concentration and the formation of porous corrosion products, leading to the change of corrosion rate.

"The paper presents the studies on the steels samples performed by Mössbauer spectroscopy. The 57Fe isotope is most studied isotope by this method. The first studies were realized in the transmission geometry. Thus were studied industrial Fe-C steels, Fe-Si electrotechnical steels, the action of an organic inhibitor on the corrosion of OL37 steel and the compound formed at the Fe-Sn interface of a babbit bearing. The following studies were concentrated on the surface studies. The development of new detectors for surface studies was accomplish. The corrosion of industrial carbon steel in diluted ammoniacal media was studied. The inhibition effect of three organic compounds on the corrosion of carbon-steel in ammoniacal solutions was determined. The corrosion of industrial carbon steel in HCl solutions was investigated. The inhibition effect of five organic compounds for samples corroded in solutions of HCl were determined. Low carbon Fe-C steel surface has been studied before and after electrolytic galvanisation. "

Polyaniline/Silicon Dioxide Composite-Based Coating for Corrosion Protection in Geothermal Systems

Superhydrophobic zinc oxide/epoxy coating prepared by a one-step approach for corrosion protection of carbon steel

Through implementation of electrochemical and surface analytical techniques, we investigate the behavior of magnetite (Fe3O4) and mixed metal (M) magnetite (MxFe3-xO4) layers on carbon steel surfaces in CO2 environments. Initially, Fe3O4 layers formed naturally at 250°C are evaluated, to fully characterise the behaviour of Fe3O4 layers and their role in carbon steel corrosion across a range of CO2-saturated conditions. Gravimetric measurements were performed to determine corrosion rates, complemented by the implementation of X-ray diffraction and scanning electron microscopy to shed further light on the influence of Fe3O4 layers on carbon steel corrosion. To simplify the evaluation of metal dopants, Fe3O4 and MxFe3-xO4 layers were formed on carbon steel by electrodeposition (in sodium hydroxide, metal sulphate solutions at 80°C for 30 min) with similar characteristics to natural layers. The layered coupons were then immersed in a CO2-saturated, pH 5, 50°C solution at atmospheric pressure (aggressive conditions for Fe3O4 survival). EIS measurements were implemented to evaluate the corrosion behaviour of the underlying steel, whilst galvanic corrosion was measured using zero resistance ammetry by coupling the layered coupon to a bare carbon steel coupon. The addition of magnesium and zinc to the Fe3O4 layer enhanced galvanic interaction but showed similar corrosion protection to Fe3O4 layers. The addition of manganese reduced galvanic currents marginally but dramatically reduced the corrosion protection provided by the layer.

Microbially induced corrosion (MIC) is a complex problem that affects various industries. Several techniques have been developed to monitor corrosion and elucidate corrosion mechanisms, including microbiological processes that induce metal deterioration. We used zero resistance ammetry (ZRA) in a split chamber configuration to evaluate the effects of the facultatively anaerobic Fe(III) reducing bacterium Shewanella oneidensis MR-1 on the corrosion of UNS G10180 carbon steel. We show that activities of S. oneidensis inhibit corrosion of steel with which that organism has direct contact. However, when a carbon steel coupon in contact with S. oneidensis was electrically connected to a second coupon that was free of biofilm (in separate chambers of the split chamber assembly), ZRA-based measurements indicated that current moved from the S. oneidensis-containing chamber to the cell-free chamber. This electron transfer enhanced the O2 reduction reaction on the coupon deployed in the cell free chamber, and consequently, enhanced oxidation and corrosion of that electrode. Our results illustrate a novel mechanism for MIC in cases where metal surfaces are heterogeneously covered by biofilms.

Corrosion of metal infrastructure due to microbial activity has been widely reported in many sectors and has been frequently studied under mesophilic conditions (<50°C). However, less is known about this degradation process at thermophilic (>50°C) temperatures that characterize many oil- and gas-producing operations. We used a thermophilic sulfate-reducing consortium (TSRM) enriched from offshore-produced water fluids to determine microbial corrosion of mild carbon steel at 60°C in the presence or absence of an organic electron donor (lactate or volatile fatty acids) and in the presence of riboflavin, a redox mediator previously reported to enhance microbial corrosion by pure isolates. Incubations of the TSRM consortium showed the highest corrosion rate in the absence of an organic electron donor, suggesting that the carbon steel itself served as an electron donor. Higher corrosion rates corresponded to increased numbers of localized pits formed. Scanning electron micrographs showed microbial cells with elongated filaments incubations when Fe0 served as an electron donor, potentially contributing to the direct uptake of electrons from iron. The addition of 20 ppm riboflavin did not enhance corrosion rates by the mixed TSRM consortium under the tested conditions. Microbial community analysis showed the TSRM culture to contain diverse anaerobic taxa and substantially distinct planktonic and coupon surface-attached communities. Overall, this study showed that thermophilic microbial communities containing sulfate-reducers can contribute to the corrosion of metal infrastructure operated or maintained at higher temperatures even in the absence of organic substrates, provided sulfate is present.

Effect of cations on corrosion of zinc and carbon steel covered with chloride deposits under atmospheric conditions

Adsorption and inhibition mechanism of (Z)-4-((4-methoxybenzylidene)amino)-5-methyl-2,4-dihydro-3H-1,2,4-triazole-3-thione on carbon steel corrosion in HCl: Experimental and theoretical insights

<p class="PaperTitle"><span lang="EN-GB">This study investigates the inhibition potential of Vernonia amygdalina stem extract (VAE) on the corrosion of mild carbon steel immersed in 1 M HCl solution containing various concentrations of the inhibitor. The corrosion rate and inhibition efficiency were evaluated using mass loss and adsorption techniques. The results revealed that VAE efficiently inhibits the corrosion rate of mild carbon steel immersed in the acidic medium. The concentration of 0.6 g/L provides the highest inhibition efficiency of 78.1 %. The adsorption process was consistent with the physisorption mechanism and obeyed the Langmuir isotherm. The functional groups responsible for inhibition were identified using Fourier Transform Infrared (FTIR) spectra. The surface morphology of the corroded samples examined with Scanning Electron Microscope (SEM) revealed the presence of protective oxide layer. Inhibition efficiency was found depended on the presence of oxalate, phytate, tannins, saponins and flavonoids in the VAE. It has been concluded that VAE is safe, cheap and efficient corrosion inhibitor for mild carbon steel.</span></p>

Corrosion of low carbon steel by microorganisms from the ‘pigging’ operation debris in water injection pipelines

Corrosion is a major concern in transmission pipelines that transport captured CO2. While dry CO2 is noncorrosive, significant corrosion has been reported in dense phase CO2 with trace amounts of water and impurities such as O2, H2S, SOx, and NOx. The aim of this work is to improve our understanding of the physicochemical aspects on the corrosion of carbon steels in the high-pressure environments associated with CO2 transmissions pipelines. The effect of flow on the corrosion of X65 carbon steel was investigated in a series of autoclave tests with different combinations of impurity concentrations in supercritical CO2 condition (8 MPa and 35°C). The corrosion rate of samples was determined by weight loss measurements. The surface morphology and the composition of the corrosion product layers were analyzed by using surface analytical techniques (SEM and EDS). Localized corrosion was measured via surface profilometry after corrosion products were removed. Results showed that no corrosion was observed in the supercritical CO2 with 650 ppm of water, 50 ppm SO2, and 100 ppm NO, but corrosion occurred when SO2 concentration was increased to 4500 ppm and 40,000 ppm of O2 was added to the system. The presence of flow significantly accelerated the corrosion of carbon steel. Furthermore, localized corrosion was observed in the presence of both O2 and flow.

The synergism of CeCl3 (Ce) with cysteine (Cys) on the corrosion of P110 carbon steel in 3% NaCl solutions was investigated by electrochemical methods and surface analysis. The results showed that CeCl3 and cysteine do little to inhibit the corrosion of carbon steel, but the combination of CeCl3 with cysteine has obvious synergistic effect on the corrosion of carbon steel and the corrosion inhibition efficiency was improved significantly. The potentiodynamic polarization curves indicated that the mixture of CeCl3 and cysteine acts as a cathodic inhibitor. Scanning electron microscope (SEM) and Infrared (IR) reflection spectra showed the synergistic inhibition effect was formed by the complexes between rare earth Ce(III) ion and amino acid.

Corrosion of carbon steel in clay compact environments at 90 °C: Effect of confined conditions