Corrosion Of Q235 Carbon Steel Research Articles

Synergistic inhibition effect of Chlorella sp. and benzotriazole on the corrosion of Q235 carbon steel in alkaline artificial seawater

The interaction of microalgae on the reinforced concrete with corrosion inhibitor is not well understood. Moreover, the inhibition role of microalgae on corrosion has been reported in recent years. In this study, the corrosion inhibition behavior of Q235 carbon steel (CS) due to the presence of Chlorella sp. and benzotriazole (BTA) in alkaline artificial seawater was investigated by means of weight loss, electrochemical measurements including open circuit potential, electrochemical impedance spectroscopy, and potentiodynamic polarization curves, and surface analysis including scanning electron microscopy, energy dispersion spectrometer, and X-ray photoelectron spectroscopy. The results of reduced corrosion rates in the algae-BTA system demonstrated that Chlorella sp. could facilitate the corrosion inhibition efficiency of BTA on the CS specimens. Moreover, polarization measurement showed the algae-BTA system had a mixed-type corrosion inhibition effect. The mechanisms of inhibition were proposed to be the precipitation of iron complexes such as Fe-BTA-EPS and Fe-BTA and iron compounds on the steel surface in the presence of the microalgae and BTA–. This study highlights the application of CS corrosion control by combining biological and chemical approaches that can be used for future research and practice, rather than purely chemical approaches.

A comparative study of the corrosion of Q235 carbon steel in six different strains of marine-isolated sulfate reducing prokaryote

Biocorrosion in marine environments is often associated with biofilms of sulfate reducing prokaryotes. However, the corrosion behaviors of steel differed greatly between the bacterial species. In this study, six strains of sulfate reducing prokaryote including 3 strains of strictly anaerobic bacteria and 3 strains of facultative anaerobic bacteria were isolated from the steel rust immersed in Sanya, China. The corrosion behavior of Q235 carbon steels by isolated six strains was studied by weight loss analysis, electrochemistry measurements, and surface morphology observation. In addition, the relationship between bacterial corrosivity and strain type was investigated. The results indicated that there is no direct relationship between the corrosivity of bacteria and strain type, whether the bacteria were strictly anaerobic or not. The corrosion rates of steel coupons fluctuated with the strain properties and soaking time. Among the strains tested, the strains belonging to Proteobacteria had relatively high corrosion rates on steel coupons, whereas, strain Virgibacillus Dokdonensis of Firmicutes has the lowest corrosion rate. The results provide a guiding basis for exploring the mechanism of microbial corrosion and controlling marine microbial corrosion.

Visualization and simulation investigation of Copper-Nickel alloy and carbon steel galvanic corrosion in marine environment

Corrosion of Q235 carbon steel and the BFe30-1–1 copper-nickel alloy was studied in seawater with electrochemical methods and surface characterization. The open circuit potential (OCP) for the copper-nickel alloy and carbon steel were −225 mV and −700 mV, respectively. A Gel visualization test showed that Turnbull's blue was precipitated on the surface of Q235, which indicated accelerated corrosion of the Q235 anode after coupling. The increased Kelvin potential determined for the Q235 surface with a Scanning Kelvin Probe test indicated that the Q235 surface generated electrons and transferred them to the BFe30-1–1 surface, which resulted in the protection of BFe30-1–1. These tests showed that the Q235 anode underwent corrosion, and the BFe30-1–1 cathode was protected after coupling in seawater. Surface analyses showed that Q235 corroded faster over time due to electric coupling, while BFe30-1–1 corrosion was inhibited by a stable passivation film. Analysis of the physical phase showed that the corrosion products of Q235 were β-FeOOH, α-FeOOH and Fe3O4, and the BFe30-1–1 corrosion products were Cu2O and Cu2Cl(OH)3. The electrochemical and numerical results were consistent, indicating an accurate prediction of the galvanic corrosion process.

Corrosion of Q235 carbon steel induced by sulfate-reducing bacteria in groundwater: corrosion behavior, corrosion product, and microbial community structure.

Microbiologically influenced corrosion (MIC) is one of the reasons leading to the service failure of pipelines buried in the soil. In this work, the effect of sulfate-reducing bacteria (SRB) on the corrosion behavior of Q235 carbon steel in groundwater was investigated by electrochemical methods, surface analysis, and biological analysis. The results show that SRB utilizes iron as electron donor to sustain the vital activities of organic carbon-starved groundwater during the 14-day experimental period. The microbial community composition analysis at the genus level demonstrate that the diversity and richness decrease after corrosion, and the dominant SRB species has changed from Desulfovibrio to Desulfosporosinus. Moreover, the impedance of the carbon steel in the presence of biofilm was 1 order of magnitude higher than that of other periods in the electrochemical test, indicating that the biofilm and formed ferrous sulfide layer impeded the occurrence of corrosion. Although the 3D topography indicated that the surface of carbon steel was more uneven and pits were increased in the presence of SRB, the average weight loss (0.0396 ± 0.0050 g) was much higher than that without SRB (0.0139 ± 0.0007 g). These results implied that the growth of SRB makes the corrosion process of Q235 carbon steel more complicated.

Synergistic inhibition effect of imidazoline and thiourea on pitting corrosion of Q235 carbon steel

Pitting corrosion is a significant issue which significantly shorten the service life of carbon steel. In this study, imidazoline and thiourea are combined to assess the synergistic in the localized corrosion of Q235 carbon steel by a combined system. In detail, five different proportions of corrosion inhibitors are used in the simulated corrosion solution (5 wt. % NaCl + 0.5 wt. % CH3COOH + 1.0 wt. % Na2S) in the closed area to investigate the corrosion inhibition performance of Q235 steel at 80 °C. The corrosion behavior of the steel in the simulated solution was investigated using potentiodynamic polarization test and electrochemical impedance spectroscopy test. Due to the combination of imidazoline (IM) and thiourea (TU) corrosion inhibitors, the corrosion inhibitors in the simulated solution of the occlusion zone reduce the migration of corrosive anions to the occlusion zone and slowed the acidification of the solution resulting in lower concentrations of Cl- and S2- to varying degrees and reaching a higher pH of the solution. As a result, the compounded corrosion inhibitors exhibit improved corrosion inhibition rate (80 mg/L IM+20 mg/L TU (86.91 %), 50 mg/L IM+ 50 mg/L TU (95.67 %), 20 mg/L IM+ 80 mg/L TU (86.16 %)) to Q235 steel, which is superior to that using imidazoline (63.42 %) or thiourea (92.77 %) alone. This enhanced performances fully prove the synergistic effect of imidazoline with thiourea.

Effect of One Sulfate-Reducing Bacterium SRB-Z Isolated from Pearl River on the Corrosion Behavior of Q235 Carbon Steel

Sulfate-reducing bacteria (SRB) have long been reported to participate in metal corrosion processes in anoxic environments. However, existing theories still need enrichment by identifying more corrosive microorganisms and exploring more plausible microbiologically-influenced corrosion pathways. In this study, a strain SRB-Z was isolated from the Pearl River in Guangzhou, and its effect and mechanisms on corrosion of Q235 carbon steel were examined. The biofilms, corrosion products, pits, and corrosion electrochemistry were characterized by SEM, XPS, CLSM, EDS, white light interferometer 3D profilometry, and electrochemical analysis, respectively. The results of this study indicate that SRB-Z could cause serious pitting of Q235 carbon steel. The maximum pit depth reached 54 μm after immersion corrosion for 7 days. Strain SRB-Z promoted the cathodic reaction rate of Q235. The relative analyses revealed that pitting corrosion occurred because of galvanic corrosion caused by the formation of an FeS-SRB/Fe galvanic couple under the synergistic effect of the SRB-Z biofilm and its metabolite (H2S) on the Q235 coupon surfaces.

Developing a regional environmental corrosion model for Q235 carbon steel using a data-driven construction method

Studying the impact of the environment on metal corrosion is of considerable significance for the safety assessment of buildings and the life prediction of equipment. We developed a new regional environmental corrosion model (RECM) to predict the atmospheric corrosion of Q235 carbon steel based on measured environmental data and corrosion rates obtained from one-year-long static coupon tests. The corrosion of metals varies depending on the environment; therefore, the ability of the model to distinguish such differences is crucial for accurately predicting corrosion. Herein, the regions in which the test sites were located were divided based on the basic principles of atmospheric corrosion. Furthermore, random forest was used to assess the importance of various environmental factors in the corrosion process within each region, which established a close relationship between corrosion and environmental conditions. Our results showed that the accuracy of the RECM is higher than that of the dose-response function of the ISO9223-2012 standard. The method of model construction can be realized automatically using a computer.

Microbiologically Influenced Corrosion of Q235 Carbon Steel by Ectothiorhodospira sp.

The biological sulfur cycle is closely related to iron corrosion in the natural environment. The effect of the sulfur-oxidising bacterium Ectothiorhodospira sp., named PHS-Q, on the metal corrosion behaviour rarely has been investigated. In this study, the corrosion mechanism of Q235 carbon steel in a PHS-Q-inoculated medium is discussed via the characterization of the morphology and the composition of the corrosion products, the measurement of local corrosion and the investigation of its electrochemical behaviour. The results suggested that, initially, PHS-Q assimilates sulfate to produce H2S directly or indirectly in the medium without sulfide. H2S reacts with Fe2+ to form an inert film on the coupon surface. Then, in localised areas, bacteria adhere to the reaction product and use the oxidation of FeS as a hydrogen donor. This process leads to a large cathode and a small anode, which incurs pitting corrosion. Consequently, the effect of PHS-Q on carbon steel corrosion behaviour is crucial in an anaerobic environment.

Synergistic inhibition mechanism of phosphate and phytic acid on carbon steel in carbonated concrete pore solutions containing chlorides

Synergistic inhibition performance of trisodium phosphate (TSP) and phytic acid (PA) on chloride-induced corrosion of Q235 carbon steel in carbonated concrete pore solutions was investigated using electrochemical measurements, XPS, AFM and SEM/EDS. At the optimum concentration ratio of TSP and PA, the mixed inhibitor showed an inhibition efficiency of 89.8 % after long-term chloride exposure due to the progressive formation of a protective oxide film with specific bilayer structure on the steel surface, and the corresponding synergistic inhibition mechanism was proposed. However, the excessive content of PA could compete with TSP, thereby leading to an antagonistic effect with reduced inhibition efficiencies.

Novel 1, 3, 5‐triazine derivative is a highly efficient inhibitor of corrosion of Q235 carbon steel in an acidic medium

AbstractA novel triazine derivative, 2, 4‐diamino‐6‐dodecamido‐1, 3, 5‐triazine (DT), is synthesized by the dehydration condensation of melamine and lauric acid, and its inhibitive performances for the corrosion of Q235 carbon steel in 1 mol/L HCl solution is investigated by electrochemical polarization, electrochemical impedance spectroscopy, scanning electron microscopy, and atomic force microscope. The results reveal that its best inhibition efficiency reaches 96.98% at a concentration of 2.5 g/L. The calculation results of kinetic and thermodynamic parameters indicate that the adsorption of DT on carbon steel surface obeys Langmuir adsorption isotherm with both physical and chemical adsorption. It is demonstrated that long‐chain amide (>8C) substituted 1, 3, 5‐triazine derivative has the synergistic corrosion inhibition effect of the surface fixation on metal iron and the hydrophobic adsorption layer.

Prediction of tempo-spatial patterns and exceedance probabilities of atmospheric corrosion of Q235 carbon steel across China.

To reduce the losses caused by the atmospheric corrosion of carbon steels, it is important to establish a prediction model to determine the corrosion rate of carbon steels in natural environments. In this study, a prediction model of atmospheric corrosion of Q235 carbon steel (PMACC-Q235) in China was established by coupling the mean impact value algorithm and back propagation artificial neural network. Tempo-spatial patterns of corrosion rates in five long-exposure time categories across China were analyzed. Ten main factors affecting the atmospheric corrosion of Q235 were identified. The corrosion rates in a single year were similar (approximately 30 μm/a) and larger than those for 2 (25.30 μm/a) and 3 years (21.66 μm/a). The spatial corrosion rates in the northwestern areas were primarily lower than those in southeastern coastal areas. This could be influenced by climatic factors, such as temperature, humidity, and precipitation. All corrosion rates reached the C2 level (>1.3 μm/a), and there was some possibility that they reached higher corrosion levels. The largest probability for the C3 level in all periods was an average of 0.91, and that for the C4 level was 0.83. Spatially, higher probabilities were mainly located in the southern area, especially in Hainan, located in the south and surrounded by sea. Corrosion rates largely varied among climatic zones, and mean corrosion rates in the tropical monsoon climate zone were the largest (average of three periods 33.39 μm/a). SO2 and soluble-dust fall had the largest impact on the variations in the corrosion rates among different climatic zones.

Electron donor dependent inhibition mechanisms of D-phenylalanine on corrosion of Q235 carbon steel caused by Desulfovibrio sp. Huiquan2017

Mechanisms of D-phenylalanine (D-Phe) on corrosion of Q235 carbon steel caused by Desulfovibrio sp. Huiquan2017 with different electron donors were investigated. When lactate was main electron donor, D-Phe did not influence the average corrosion loss, but inhibited localized corrosion by repressing biofilm formation and altering biofilm structure, which was supported by comparative transcriptome analysis. When lactate and yeast extract were removed, D-Phe significantly reduced corrosion loss, and weakened selective phase corrosion and localized corrosion. It may due to the proceeding of the Stickland reaction, in which L-cysteine is electron donor and L-Phe transformed from D-Phe by bacteria is electron acceptor.

Modeling research of initial atmospheric corrosion of Q235 carbon steel based on electrical resistance probe

PurposeThis paper aims to discover the mathematical model for Q235 carbon steel corrosion date acquired in the initial stage of atmospheric corrosion using electrical resistance probe.Design/methodology/approachIn this paper, mathematical approaches are used to construct a classification model for atmospheric environmental elements and material corrosion rates.FindingsResults of the experiment show that the corrosion data can be converted into corrosion depth for calculating corrosion rate to obtain corrosion kinetics model and conform corrosion acceleration phase. Combined with corresponding atmospheric environmental elements, a real time grade subdivision model for corrosion rate can be constructed.Originality/valueThese mathematical models constructed by real time corrosion data can be well used to research the characteristics about initial atmospheric corrosion of Q235 carbon steel.

In-situ monitoring of pitting corrosion of Q235 carbon steel by electrochemical noise: Wavelet and recurrence quantification analysis

Abstract Pitting corrosion of Q235 carbon steel in 0.25 M NaHCO3 with different concentrations of chloride ions was in-situ monitored by electrochemical noise (EN) technique, and the EN signals were analyzed by transient shape analysis, wavelet analysis and recurrence quantification analysis (RQA). Four typical electrochemical current noise (ECN) transients corresponding to different pitting stages including passivation, random metastable pitting, transition stage and stable pitting stage were observed. It was found that the RQA parameters, recurrence rate (R) and determinism (D), show the ability to separate the four ECN transients, while wavelet parameter show poor ability to distinguish the ECN transients arising from random metastable pitting and transition stage. Furthermore, the ratio of D and R (η) was proposed to monitor the pitting corrosion. The average value of η for the passivation and random metastable pitting is 1.88 and 1.63, and it gradually increases to around 6 during the transition stage and early stable pitting stage, the value slightly decreased to 4.16 at the late stable pitting stage. The detailed relationship between the EN characteristic parameters and dynamic process of pitting corrosion is discussed.

Impact factor analysis, prediction, and mapping of soil corrosion of carbon steel across China based on MIV-BP artificial neural network and GIS

Q235 carbon steel is one of the most widely used carbon steels, and soil corrosion and failures of it caused accidents, casualties, and great financial losses. Corrosion of Q235 carbon steel differed in spatial because of spatial variation in soil environmental factors. However, the national scale spatial pattern of soil corrosion of Q235 carbon steel across China has not been explored. The values of 12 impact factors, corrosion rate, and pitting corrosion rate at 25 sites covered all soil types in China were collected. Mean impact value (MIV) algorithm and back propagation artificial neural network (BP ANN) were combined and applied in the impact factor analysis. Prediction models for corrosion rate and pitting corrosion were developed based on BP ANN. The proposed prediction models and information about soil properties with high resolution (1 km × 1 km) were used in the prediction of corrosion rate. Based on geographical information system (GIS), the national scale spatial pattern of soil corrosion of Q235 carbon steel across China were analyzed. The water content and pH were of the largest influence (|MIV| > 0.522) on both corrosion rate and pitting corrosion rate. For prediction models of corrosion rate and pitting corrosion rate, the predicted values were close to the measured values. Corrosion rates were of higher spatial differences, ranged from 0.632 to 5.181 g/(dm2·a). Pitting corrosion rates in the northeast were higher than other areas, which might be caused by higher values of total salt content, organic matter, and total voidage. Average corrosion rate in soil type 1 (1.161 mm/a) was nearly two times of that in soil type 2 (0.610 mm/a) and over three times of that in other types, indicating that corrosion rate varied largely among different soil types. The importance of 12 impact factors of corrosion of Q235 carbon steel were evaluated, and the national scale corrosion rate and pitting corrosion rate in China were predicted and mapped for the first time. Both pitting corrosion rates and corrosion rates were of strong spatial variation.

The study of under deposit corrosion of carbon steel in the flowback water during shale gas production

Serious under deposit corrosion could occur in the shale gas flowback water environment. In this work, under deposit corrosion of Q235 carbon steel in a simulated CO2/O2-containing shale gas flowback water was studied using wire beam electrode, potentiodynamic polarization curves, electrochemical impedance spectroscopy, scanning electron microscopy, X-ray diffraction and X-ray photoelectron spectroscopy. The results show that there is a galvanic corrosion effect between the deposit-covered electrode and bare electrode. The polarity of the deposit-covered electrode and bare electrode is reversed at 3 h. Before 3 h immersion, deposit-covered electrode acts as cathode and bare electrode acts as anode. However, after 3 h immersion, deposit-covered electrode turns into anode while bare electrode converts into cathode. The obvious localized corrosion characteristics can be observed under deposit and the corrosion products mainly consist of Fe2O3, Fe3O4 and FeCO3. WBE can be used to in situ monitor the occurrence and development of local corrosion under deposit. The current maps of WBE show that severe local corrosion has occurred on the electrodes covered by deposit.

Effect of relative humidity on corrosion of Q235 carbon steel under thin electrolyte layer in simulated marine atmosphere

PurposeThe purpose of this paper is to obtain the environmental factor, which has the greatest effect on the corrosion rate of Q235 carbon steel under thin electrolyte layer, and to analyze the effect of this factor on the corrosion morphology, corrosion products and polarization process of Q235 carbon steel.Design/methodology/approachAn electrochemical device, which can be used under thin electrolyte layer is designed to measure the corrosion current in different environments. Response surface methodology (RSM) is introduced to analyze the effect of environmental factors on corrosion rate. Scanning electron microscope (SEM) and X-ray diffraction (XRD) technique are used to analyze the results. The Tafel slopes of anode and cathode in different humidity and solution are calculated by least square method.FindingsThe three environmental factors are ranked according to importance, namely, humidity, temperature and chloride ion deposition rate. In a high humidity environment, the relative content of α-FeOOH in the corrosion product is high and the relative content of β-FeOOH is low. The higher the humidity, the lower the degree of anodic blockage, whereas the degree of cathodic blockage is independent of humidity. The above experiments confirm the effectiveness and efficiency of the device, indicating it can be used for the screening of corrosive environmental factors.Originality/valueIn this paper, an electrochemical device under thin film is designed, which can simulate atmospheric corrosion well. Subsequent SEM and XRD confirmed the reliability of the data measured by this device. The introduction of a scientific RSM can overcome the limitations of orthogonal experiments and more specifically and intuitively analyze the effects of environmental factors on corrosion rates.

Corrosion inhibition efficiency of triethanolammonium dodecylbenzene sulfonate on Q235 carbon steel in simulated concrete pore solution

The performance of triethanolammonium dodecylbenzene sulfonate (TDS), a type of cationic surfactant, against corrosion of Q235 carbon steel in an alkaline medium simulating concrete pore solution was studied by different electrochemical test methods. Electrochemical impedance spectroscopy (EIS) results revealed an increase in the charge transfer resistance of specimens in the presence of TDS, compared with the blank system. Both donor and acceptor density with the increase in TDS concentration, evident in the Mott-Schottky plots. Furthermore, observations using an optical microscope and the analysis of X-ray photoelectron spectroscopy measurements corroborated that the pitting corrosion of the metallic surface was significantly hindered with the addition of TDS into the simulated concrete pore solution.

Corrosion of Q235 Carbon Steel in Seawater Containing Mariprofundus ferrooxydans and Thalassospira sp.

Iron-oxidizing bacteria (IOB) and iron-reducing bacteria (IRB) can easily adhere onto carbon steel surface to form biofilm and affect corrosion processes. However, the mechanism of mixed consortium induced carbon steel corrosion is relatively underexplored. In this paper, the adsorptions of IOB (Mariprofundus ferrooxydans, M. f.), IRB (Thalassospira sp., T. sp.) and mixed consortium (M. f. and T. sp.) on surface of Q235 carbon steel and their effects on corrosion in seawater were investigated through surface analysis techniques and electrochemical methods. Results showed that local adhesion is a typical characteristic for biofilm on surface of Q235 carbon steel in M. f. and mixed consortium media, which induces localized corrosion of Q235 carbon steel. Corrosion rates of Q235 carbon steel in different culture media decrease in the order: rM.f. > rmixed consortium > rT. sp. > rsterile. The evolution of corrosion rate along with time decreases in M. f. medium, and increases then keeps table in both T. sp. and mixed consortium media. Corrosion mechanism of Q235 carbon steel in mixed consortium medium is discussed through analysis of surface morphology and composition, environmental parameter, and electrochemical behavior.

Aniline trimer-including carboxymethylated β-cyclodextrin as an efficient corrosion inhibitor for Q235 carbon steel in 1 M HCl solution.

In this work, a water-soluble host–guest complex containing carboxymethylated beta-cyclodextrin (CM-β-CD) and an aniline trimer (AT) was synthesized. The application of AT–CM-β-CD as an inhibitor for alleviating the corrosion of Q235 carbon steel in 1 M HCl solution was investigated by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). Results showed that the inhibition efficiency was significantly increased in the presence of AT–CM-β-CD, and the inhibition efficiency was up to 99.2% when the concentration of AT–CM-β-CD was 250 mg L−1. Field emission scanning electron microscopy (SEM) and laser scanning confocal microscopy (LSCM) confirmed that the corrosion inhibitor had excellent corrosion inhibition effects due to the formation of an adsorption film on the surface of Q235 carbon steel. According to the data extracted from the Langmuir adsorption model, AT–CM-β-CD absorption involves both physisorption and chemisorption.