Corrosion Of Pipeline Steel Research Articles

Corrosion behavior of X65 steel in gaseous and liquid CO2 transport environments containing multiple impurities and different H2O content

The mechanism of H2O content in different CO2 phase states on the corrosion of pipeline steel was studied by using high-pressure corrosion simulation tests, scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDS), X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and water chemistry simulation calculations. The results show that the corrosion mechanism of X65 steel did not change significantly under different CO2 phase state systems, and the corrosion products were similar. As the H2O content of the system increased, the sulfur-containing products in the corrosion products increased and the degree of corrosion worsened. Additionally, because the aqueous phase formed by the liquid CO2 system contained more corrosive substances, which promote the electrochemical corrosion process of X65 steel, the corrosion degree of X65 steel in a liquid CO2 system was significantly higher than that of X65 steel in a gaseous CO2 system.

Forecast of the rate of underground corrosion of steel pipelines. Review

Forecast of the rate of underground corrosion of steel pipelines. Review

Unique corrosion reinforcement mechanism of pipeline oil sludge with sulfate-reducing bacteria on X60 steel and the targeted long-term inhibition of dazomet delivery

The mutual promotion behavior of pipeline oil sludge and wild SRB on pipeline steel corrosion was investigated. The resistance probe technique was used for long-term monitoring of MIC underneath SRB oil sludge. Corrosion of pipeline steel under oil sludge was the result of multifactorial coupling. SRB biofilm enhanced the conductivity of the oil sludge that serves as an electron transfer "bridge" between the SRB and carbon steel, accelerating the extracellular electron transfer process of MIC, and hence the dissolution of the carbon steel. Delivery of dazomet (DMTT) was a long-term strategy for mitigating pipeline corrosion under SRB oil sludge.

Electrochemical Study on the Macro-Cell Corrosion of Pipeline Steel Partially Covered by Different Kinds of Mineral Deposits.

This study presents the impact of mineral deposits (SiO2, Al2O3, and CaCO3) on the corrosion behavior of X65 pipeline steel in CO2-containing brine solution with low pH. The study investigates the initiation and propagation of under deposit corrosion (UDC) using a wire beam electrode (WBE) partially covered by different mineral deposit layers, in conjunction with electrochemical measurements and surface characterization. The results indicate that the corrosion behavior varies, depending on the characteristics of the deposit. During the test period, the Al2O3-covered steel acted as the main anode with more negative potential, while the bare steel acted as the cathode. The SiO2-covered steel acted as the cathode with more positive potential and a localized FeCO3 layer formed beneath the silica mineral. The CaCO3-covered steel initially acted as an anode with a more negative potential but transformed into the cathode at the end of the test. Additionally, shallow and small pits were observed beneath the deposits with the depth in the sequence Al2O3 > SiO2 > CaCO3.

Microbial Corrosion of X60 Pipeline Steel in Groundwater Containing Sulfate-Reducing Bacteria/Iron-Oxidizing Bacteria Mixed Colonies

Microbial Corrosion of X60 Pipeline Steel in Groundwater Containing Sulfate-Reducing Bacteria/Iron-Oxidizing Bacteria Mixed Colonies

AC corrosion of steel pipeline under cathodic protection: A state‐of‐the‐art review

AbstractBy the advancement of the oil, electricity, and transportation industries, an increasing number of oil and gas pipelines were buried alongside high‐voltage alternating current (AC) transmission lines and electrified railways. This resulted in a growing issue of AC interference in buried pipelines. Previous studies have shown that the presence of AC interference can result in severe corrosion damage to metallic structures, even when cathodic protection (CP) is available. This paper provides a state‐of‐the‐art review on AC corrosion of cathodically protected pipeline steel. Specifically, attention is paid to research areas including influencing factors in AC corrosion for pipelines under CP, existing AC protection criteria, corrosion risk assessment based on probability of failure, numerical simulation in AC corrosion, and mitigation of AC corrosion. Each area of research is reviewed in detail and the corresponding technical gaps and future research opportunities are identified and discussed.

Newly synthesized nanohybrids based on gallic acid derivatives for pipeline steel corrosion in hydrochloride acid medium

The present study involves the synthesis and characterization of two innovative non-ionic surfactants and their nanohybrid derivatives, to evaluate their efficacy as corrosion inhibitors for pipeline metal. The synthesis procedure followed an environmentally benign method. Utilizing elemental analysis, Fourier infrared (FTIR), and NMR spectroscopy, the newly synthesized surfactants were verified and evaluated. Moreover, using UV–visible (UV–Vis) spectroscopy as well as examining electrons the structure of the prepared gold nanoparticles was analyzed with SEM, while their nanohybrid derivatives were verified. With the nanohybrid molecules, 99.9 % and 99.8 % at 200 ppm for NHTO and NHTS, respectively, the molecules demonstrated outstanding corrosion inhibitive efficacy in acidic environments. The molecules fit the Langmuir adsorption isotherms and under acidic circumstances were discovered to chemisorb on the mild steel surfaces with unrestricted energies of binding of −33.10 and − 33.67 kJ/mol for NHTO and NHTS molecules.

The Corrosion Behavior of X100 Pipeline Steel in a Sodium Chloride Solution Containing Magnesium and Calcium.

The influences of Mg2+ and Ca2+ on the short-term (1800 s) corrosion behavior of X100 pipeline steel were investigated in a sodium chloride (NaCl) solution saturated with CO2. Either Ca2+ or Mg2+ in the solution inhibited the short-term corrosion of X100 pipeline steel, with the corrosion current density decreasing from 262.4 μA cm-2 to 163.5 μA cm-2 or 80.8 μA cm-2. During longer-term (8-48 h) immersion, the Mg2+ inhibited the formation of the protective scale, whereas the Ca2+ accelerated the formation of the scale. Further, an experimental equation establishing the relationship between the precipitation rate of the corrosion scale and the exposure time was proposed to quantitatively study the effects of Mg2+ and Ca2+ on the precipitation rate of the corrosion scale.

Internal localized corrosion of X100 pipeline steel under simulated flow conditions

In this paper, a wire beam electrode (WBE) was used to explore the local corrosion processes of X100 pipeline steel in simulated solution containing HCO3− in static and flow conditions. The results indicated that the WBE's current density mapper was remarkably consistent with the polarization curves. Therefore, WBE is an efficient online corrosion monitoring approach. The WBE discovered undetectable pitting and passivation qualities within the X100 pipeline steel under static conditions. However, the corrosion current density of X100 steel was substantially higher under flow conditions than under static ones. The addition of HCO3− ions significantly decreased the corrosion resistance of the X100 steel. In the 0.3 mol/L HCO3− simulated solution, dynamic corrosion was 92 times faster than static. The corrosion of X100 steel was enhanced by the combined effects of fluid movement and HCO3− ions. Additionally, X100 steel produced significant irregular edge pitting when the critical level of HCO3− was 0.2 mol/L under dynamic conditions, and an erosion theory was proposed to explain this phenomenon.

Role of Fe oxide in the underdeposit corrosion of pipeline steel in oilfield produced water containing SRB

AbstractThe corrosion behavior of C20 pipeline steel was studied under Fe oxide and sand deposits in oilfield produced water containing sulfate‐reducing bacteria (SRB) via electrochemical techniques and surface analyses. A galvanic current of about 2 μAcm−2 was detected when the Fe oxide deposited sample and the bare steel were coupled in zero resistance ammeter (ZRA) mode, with the former being the anodic member of the couple. The Fe oxide deposited steel recorded severe localized corrosion after 14 days of testing in the SRB inoculated oilfield produced water. Corrosion severity decreased on the sand‐deposited steel, with general corrosion as the dominant morphology of surface attack. The development of product film was a vital factor in steel corrosion under the Fe oxide deposit.

Understanding the interaction between erosion and corrosion of pipeline steel in acid solution of different pH

The pure corrosion, erosion-corrosion and pure erosion behaviors of X65 pipeline steel in acid NaCl solution of different pH levels (ranging from 1.5 to 5.0) were studied using a rotation disc system, aiming to understand the interaction between erosion and corrosion of pipeline steel operating in acid slurry. The corrosion and erosion-corrosion performances of the steel were electrochemically measured in conjunction with surface characterizations. The pure erosion performance was studied by applying cathodic protection to eliminate the corrosion component. The propagation of the localized erosion-corrosion at different pH levels were probed using wire beam electrode. Results show that pH = 3.5 is a critical value for the transition of cathodic reaction under erosion-corrosion. In the acid fluids of pH < 3.5, the reduction of H+ is the main cathodic reaction, leading to a general erosion-corrosion feature with scattered small pits, which are initiated from the inclusions. Negative erosion-enhanced corrosion (E-C) is found at pH < 3.5 due to the wear of Fe3C networks. The oxygen reduction becomes the main cathodic reaction in the acid slurry of pH ≥ 3.5, resulting in the formation of erosion-corrosion pits and craters. The removal of the rust layer would result in positive E-C performance at pH > 3.5. Significant localized erosion-corrosion would occur at pH ≥ 3.5, where fixed major anodic sites are visualized. Obvious erosion-corrosion pits and craters would form with the occurrence of oxygen reduction. More serious corrosion-enhanced erosion (C-E) prefers to occur at the pitting areas where high macro-cell currents are registered.

Corrosion under insulation of pipeline steel in groundwater containing sulphate-reducing bacteria

ABSTRACT Corrosion under insulation is a major economic concern in the safe operations of water, oil and gas steel pipes. Herein, the external corrosion of X80 pipeline steel was examined beneath a disbonded insulation in groundwater containing sulphate-reducing bacteria (SRB). The results show that the steel under the insulation exhibited different electrochemical behaviour from the uninsulated sample in the bulk solution. A galvanic effect was detected between the steel under insulation and the uninsulated sample. Spectroscopic analysis reveals the rust layer of the insulated steel immersed in the SRB-inoculated groundwater was enriched by FeS from microbial metabolism. The steel under insulation recorded severe localised perforation, while corrosion severity was reduced on the uninsulated sample. Diffusion of ions, film development and insulation degradation played important roles in steel corrosion.

Correction to: Sulfate-Reducing Bacteria Corrosion of Pipeline Steel in Polyacrylamide Gel Used for Enhanced Oil Recovery

Correction to: Sulfate-Reducing Bacteria Corrosion of Pipeline Steel in Polyacrylamide Gel Used for Enhanced Oil Recovery

Effect of Nb-induced microstructure on pipeline steel corrosion and stress corrosion cracking performance in acidic environment

The corrosion and stress corrosion cracking response of two steels were examined in acidic environment. The surface microstructure and texture of the steels were significantly affected by a one-order-of-magnitude difference in Nb content. The Nb-containing steel had a refined microstructure, with more {110}-oriented grains, whereas the Nb-deficient steel had an irregular microstructure, containing both fine and large polygonal ferrite grains, with a strong {001}<110> component. When compared to the Nb-containing steel, the Nb-deficient steel had lower corrosion resistance, more delamination cracks, and a higher tendency for embrittlement. This disparity in performance was clearly related to the microstructural characteristics of the steels.

Corrosion Behavior on 20# Pipeline Steel by Sulfate-Reducing Bacteria in Simulated NaCl Alkali/Surfactant/Polymer Produced Solution.

The corrosion behavior of sulfate-reducing bacteria (SRB) on 20# carbon steel in the NaCl alkali-surfactant-polymer (ASP) flooding system was studied by scanning electron microscopy, electrochemical measurement, X-ray photoelectron spectroscopy, and laser confocal microscopy. The results showed that the presence of SRB results in a large viscosity loss of the system. SRB can use hydrolyzed polyacrylamide (HPAM) as a nutrient to grow, and the number of SRB remained at a high level after 15 days. Weight loss and electrochemical tests indicated that SRB promoted corrosion of pipeline steel. The corrosion of carbon steel in the early stage of immersion was inhibited by the biofilm formed on the surface, and the thick biofilm in the later stage of immersion caused serious pitting corrosion. The localized corrosion caused by SRB was not inhibited by HPAM and sodium petroleum sulfonate (surfactant) adsorbed on the surface.

Inhibition Effect of Pseudomonas stutzeri on the Corrosion of X70 Pipeline Steel Caused by Sulfate-Reducing Bacteria.

Microbiologically influenced corrosion (MIC) is a common phenomenon in water treatment, shipping, construction, marine and other industries. Sulfate-reducing bacteria (SRB) often lead to MIC. In this paper, a strain of Pseudomonas stutzeri (P. stutzeri) with the ability to inhibit SRB corrosion is isolated from the soil through enrichment culture. P. stutzeri is a short, rod-shaped, white and transparent colony with denitrification ability. Our 16SrDNA sequencing results verify the properties of P. stutzeri strains. The growth conditions of P. stutzeri bacteria and SRB are similar, and the optimal culture conditions are about 30 °C, pH 7, and the stable stage is reached in about seven days. The bacteria can coexist in the same growth environment. Using the weight loss method, electrochemical experiments and composition analysis techniques we found that P. stutzeri can inhibit the corrosion of X70 steel by SRB at 20~40 °C, pH 6~8. Furthermore, long-term tests at 3, 6 and 9 months reveal that P. stutzeri can effectively inhibit the corrosion of X70 steel caused by SRB.

Evaluation of Corrosion and Erosion-Corrosion Behavior of X65 Pipeline Steel in Flowing CO2-Saturated Electrolyte

In this study, the corrosion and erosion-corrosion behaviors of X65 pipeline steel in the flowing CO2-saturated electrolyte were electrochemically studied using a rotation disk system. The results showed that the accumulation of the Fe3C layer in the electrolyte without sand particles enhanced the cathodic reaction, increasing the corrosion rate. The increase in flow velocity facilitated the rapid accumulation of a thick Fe3C layer, which linearly increased the corrosion rate with increasing rotation speed. The sand impacts removed the corrosion product layer and broke the exposed Fe3C network, resulting in a negative synergy of erosion-enhanced corrosion. The erosion-corrosion negatively affected ferrites compared with the pearlites in an electrolyte containing sand due to the weaker erosion resistance.

Sulfate-Reducing Bacteria Corrosion of Pipeline Steel in Polyacrylamide Gel Used for Enhanced Oil Recovery

Sulfate-Reducing Bacteria Corrosion of Pipeline Steel in Polyacrylamide Gel Used for Enhanced Oil Recovery

Numerical study on stress corrosion of X70 pipeline with the combined action of pits by sulfate-reducing bacteria and constant load

The stress corrosion of pipeline steel was promoted by sulfate-reducing bacteria (SRB). However, the mechanism of SRB promoting stress corrosion is not clear. In this study, the effects of constant load, geometrical parameters and multi-pitting on stress corrosion in sea mud simulated solution were explored by establishing a 3D multi-physical finite element model to reveal the mechanism of SRB promoting stress corrosion. The results show that micron-sized pitting can cause significant local stress concentration. Pitting with similar geometries has little effect on maximum anodic current density. When the multiple pits are vertically distributed, the corrosion in the middle area of the two pitting increases. SRB-induced pitting causes stress concentration and tiny galvanic corrosion with the action of mechano-electrochemical effect, which make the pitting more likely to develop into micro-cracks in depth direction.

Probing top-of-the-line corrosion using coupled multi-electrode array in conjunction with local electrochemical measurement

An experimental method has been developed for probing top-of-the-line corrosion (TLC) of pipeline steel based on the use of the wire beam electrode (WBE) in conjunction with local electrochemical measurements. Results show that the location of the droplet, the droplet retention time, the water condensation rate and the local TLC rate could be well determined through the macro-cell current mapping and local electrochemical measurements. The precipitation and the scaling tendency of the FeCO3 beneath the droplet were quantitatively estimated. The micro-cell corrosion was significantly influenced by the thickness of the condensed water film and the protectiveness of the FeCO3 layer. The discrepancy of the film formation inside and outside the droplets was the driving force of macro-cell corrosion. The in-situ measurement and visualization of the corrosion processes and kinetics using the modified WBE could be conveniently used to facilitate the understanding of the initiation and propagation of localized TLC.