Corrosion Conditions Research Articles

Common Diseases and Maintenance Measures of Concrete Beam Bridges

Bridges are important infrastructure, and their safety, durability, and applicability are of significant importance to human life and property safety. This paper analyzes the common diseases and maintenance measures of concrete beam bridges, using the specific example of the Heihe No. 3 Bridge. The testing process, inspection content, and measuring point layout of reinforced concrete beam bridges are introduced. Furthermore, the detection methods of different types of reinforced concrete beam bridges are compared and analyzed for steel corrosion state detection, steel protection layer thickness detection, and carbonization depth detection. Finally, the paper briefly discusses the application of BIM in concrete beam bridges.

Progress of Triboelectric Nanogenerators with Environmental Adaptivity

AbstractAs a distributed environmental energy harvesting device, triboelectric nanogenerators (TENGs) inevitably encounter different and extreme application scenarios, such as environment with high temperature, high humidity, corrosion condition, frequent mechanical stimulus, and physical damages, which resulting in triboelectric performance degradation either by damaging device structure or reducing surface potential, and accelerating dissipation of surface bound charge. Therefore, tremendous efforts are dedicated to improving the TENG performance, enabling devices are competent in sustaining various challenging conditions. This review summarizes and highlights the latest research progress of strategy to achieve TENGs with high environmental adaptivity in three representative application fields of interfacial devices, wearable devices and implantable devices, aiming to gain insights in terms of material selection, structural design, preparation technology, working mode and integration strategy. The future development of the TENG would transform from static to dynamic device that possesses multifunction, high stability, autonomous response and actuation ability to adapt complex application environment. It is hoped that this review article could steer the development of environment‐adaptive TENGs to a higher level.

Size-regulated Co-doped hetero-interfaced 3D honeycomb MXene as high performance electromagnetic absorber with anti-corrosion performance

It is desirable to develop electromagnetic (EM) wave absorbers with anti-corrosion property that can suit various electronics, telecommunications, and military applications in harsh conditions. In this work, by varying the Co content in the 3D honeycomb MXene, Co/MXene composites with remarkable EM absorption performance were obtained. In particular, Co/MXene with 0.5 mmol Co displayed a minimum reflection loss (RL) of –54.3 dB at 2.34 mm and broad absorption bandwidth of 5.92 GHz at 2.02 mm. These Co/MXene composites also showed high resistance to corrosion as evidenced by very low corrosion current densities (10−6 ∼ 10−7 A cm−2) and very large polarization resistances (107 ∼ 108 Ω) when exposed to various corrosive conditions (acid, neutral, and alkaline conditions). The unique honeycomb architecture and the combined presence of Co and MXene enabled the electron transfer from Co to MXene as revealed by density functional theory simulation and suppressed the contributions from magnetic and conductive losses, thus allowing only polarization loss-originated EM dissipation behavior. Accordingly, this study introduces a simplified model to elucidate the mechanism of EM absorption, offering insights at the nano level.

Chemical Composition Effects on the Microstructure and Hot Hardness of NiCrSiFeB Self-Fluxing Alloys Manufactured via Gravity Casting

Ni-Cr-Si-Fe-B self-fluxing alloys are commonly used in hardfacing applications; in addition, they are subjected to conditions of wear, corrosion, and high temperatures, but are not used in casting applications. In this work, gravity casting is presented as a potential manufacturing route for these alloys. Three alloys with different chemical compositions were investigated with a focus on microstructure characterization, solidification path, and strengthening mechanisms. Phases and precipitates were characterized using a field emission scanning electron microscope employing energy-dispersive X-ray spectroscopy, wavelength dispersive spectroscopy, and electron backscatter diffraction. Nano- and microhardness indentations were performed at different phases to understand their contribution to the overall hardness of the studied alloys. Hardness measurements were performed at room temperature and high temperature (650 °C). The borides and carbides were the hardest phases in the microstructure, thus contributing significantly to the overall hardness of the alloys. Additional hardening was provided by the presence of hard Ni3B eutectics; however, there was also a small contribution from the solid solution hardening of the γ-Ni dendrites in the high-alloy-grade sample. The amount and size of the different phases and precipitates depended mainly on the contents of the Cr, C, and B of the alloy.

Enhancing the integrity of a buried gas pipelines: Investigating ruptures, explosions, and strengthening solutions

The present paper presents findings from a case study of a buried gas pipeline that ruptured, causing a gas cloud explosion and subsequent fire. The study aimed to identify the incident's cause and improve the pipeline's strength under specific conditions. The study measured the pipe's actual wall thickness and conducted stress analysis using analytical and finite element methods to assess its integrity under corrosion. It evaluated if the 20-inch pipeline near road crossings could withstand external forces.In conclusion, the research underscores the importance of accurately assessing the structural integrity of buried pipelines, especially under conditions of corrosion. It highlights the utility of finite element analysis in providing a more precise understanding of stress distribution and can aid in designing pipelines that are better equipped to withstand various external pressures.The investigation illustrates the importance of increasing the strength of buried natural gas pipelines, in the crossing road area and, for this purpose, it was proposed (in terms of novelty associated with the study) a solution consisting in introduction of the pipeline in protective sleeves fitted with spacer rings.

Characterization Specifications for FRP Pultruded Materials: From Constituents to Pultruded Profiles

Pultruded FRP composites have emerged as a promising alternative to traditional materials like concrete, steel, and timber, especially in corrosive environmental conditions. However, the unique properties of these composites necessitate careful consideration during their implementation, as they differ significantly from conventional materials. Proper testing and characterization of FRP pultruded materials is key for their efficient and safe implementation. However, the existing specifications are not unified, resulting in ambiguity among stakeholders. This paper aims to bridge this gap by thoroughly reviewing current destructive and non-destructive test methods for FRP pultruded materials, specifications, quality control, and health monitoring of FRP structures. Each subsection is further divided into subtopics, providing a comprehensive overview of the subject. By shedding light on these crucial aspects, this article aims to accelerate the adoption and utilization of these innovative materials in practical applications.

Comparative study of the effects of galvanic corrosion on the strength and the failure of aluminium and stainless steel bolted joints

This paper investigates the effects of bimetallic insert on corrosion, material degradation, loading capacity, stress distribution, strain distribution and failure of aluminium-stainless steel lap shear bolted assemblies. The single bolt lap shear assemblies of aluminium and stainless steel plates were performed in two settings in one of them a bimetallic insert was used. Considering that the aluminium plays the role of sacrificial anode in the aluminium-stainless steel galvanic couple, a single bolt lap shear assembly joining two aluminium plates is also considered as a reference. The experimental measurements were determined by tensile-shear testing method for three different conditions: dry condition and two corrosion states corresponding to 6 weeks and 16 weeks of accelerated corrosion tests. To support understanding of the effects of preload and friction changes due to the formation of corrosion products, finite element simulations were performed with varying preloads and friction coefficients. The study demonstrated significant effects of corrosion on loading capacity, bolt rotation and failure mode. The tensile-shear forces measured for the aluminium-aluminium assembly and aluminium-stainless steel assembly after 6 weeks of accelerated corrosion tests increased compared to the tensile-shear forces measured in dry condition. The increase in tensile-shear forces was related to the formation of corrosion products, affecting the preload and the frictional behaviour of the contacting surfaces. In agreement with experimental observations, finite element simulations demonstrated an increase in the tensile-shear force with the increase of frictional forces. The application of bimetallic inserts considerably reduces the effect of corrosion on the measured tensile-shear force of corroded assembly compared to non-corroded assembly. However, it affects the force-displacement response and failure mode compared to the response of aluminium-stainless steel assembly without bimetallic insert due to its effects on the bolt rotation and stress distribution. This needs to be considered in the design of dissimilar material bolted assembly.

Impact of Desulfovibrio ferrophilus IS5 biocorrosion time on X80 carbon steel mechanical property degradation

Three different incubation times (7, 14 and 21 d) were used to immerse X80 carbon steel dogbone coupons in deoxygenated enriched artificial seawater at 28 °C inoculated with Desulfovibrio ferrophilus (strain IS5), a very corrosive sulfate reducing bacterium to cause microbiologically influenced corrosion (MIC). It was found that 21 d immersion had the largest weight loss (24.8 mg cm−2 equivalent to 0.55 mm/year corrosion rate), smallest sessile cell count (6.8 × 108 cell/cm2), deepest pit depth (30.6 μm), and most severe mechanical degradation (9 % loss in ultimate strength and 18 % loss in ultimate strain). Due to nutrient depletion in the static incubation system, corrosion rate and sessile cell count were the highest at 0.82 mm/year and 1.1 × 109 cell cm−2, respectively at 7 d. The results from scanning electron microscopy, X-ray photoelectron spectroscopy and confocal laser scanning microscopy analyses and electrochemical corrosion measurements supported the sessile cell counts and biocorrosion weight loss data.

Measurement of granite resistivity under deep underground conditions based on van der Pauw method

With the growing demand for sustainable energy and infrastructure development in the country, the utilization of deep geothermal resources and the development of deep underground space engineering are becoming more and more important. Under the background that the country vigorously promotes the development of deep rock and soil underground space and the utilization of resources. The experiment will be performed on granite, one of the deep subsurface rocks, a rock type widely used in geotechnical research projects because of its high strength, low permeability and thermal stability. However, its properties under the extreme temperature and chemical conditions deep in the earth are unknown, and how to efficiently convert deep rocks into geothermal resources for utilization is still unknown. Therefore, studying the influence of temperature and chemical corrosion on the resistivity of granite is very important to ensure the safety and durability of underground structures and effectively utilize thermal energy resources in deep underground. This experiment will control the influence of temperature, pressure, chemical corrosion and the comprehensive effect of the three on the resistivity of granite, and indirectly measure the amount of heat absorbed in the granite rock mass. Simulate the deep underground granite under high confining pressure, high ground temperature and corrosion conditions the nature of the performance. Record, count and analyze the data, comprehensively judge the environmental interference of the granite rock formation under actual conditions and compare the destructive effects of temperature and chemical corrosion and the change of the resistivity of the rock mass. Help scientifically judge and accurately analyze the underground construction problems that may be encountered in future projects and the effective utilization of geothermal energy and provide a basis for the application of key technologies and methods.

Comparison of semiquantitative methodologies using Raman mapping for corrosion products on iron artifacts

The quantitative determination of corrosion products is essential for evaluating the corrosion state of archeological iron artifacts. This study explored two semiquantitative approaches using Raman mapping technique combined with chemometrics to quantify a binary mixture of magnetite and goethite. The first approach involved establishing quantification models using Raman spectra treated with Principal Components Regression (PCR) and Partial Least Squares (PLS) algorithms. Both the PCR and PLS model showed good predictive ability as indicated by correlation coefficients and root mean square errors (PLS: Rc2=0.9979, Rp2=0.9970, RMSEC=1.93, RMSEP =2.68, RMSECV=3.25). The second approach was based on spectral fitting using non-negative least squares (NNLS) algorithm. This method demonstrated a fair accuracy between the calculated and actual compositions. The absolute value of relative errors was 0.99%∼10.08% for Fe3O4 and 0.81%∼9.71% for α-FeOOH respectively, for compositions greater than 20%. These methods were then applied to quantify the corrosion products on an iron bar excavated from the Nanhai (South China Sea) No. I shipwreck. Compared with XRD quantitative results, Raman results showed that the spectral fitting method was superior to the established PCA and PLS quantification models in both qualitative determination and quantitative accuracy. Compositional maps depicting the distribution of different phases were also generated using spectral fitting method. It was concluded that Raman mapping has significant potential as an accurate quantitative method for the detection of iron corrosion products, and that the spectral fitting method is more suitable for determining iron corrosion compared to the PCR and PLS quantification models in this study.

Comparing Corrosion Damage Level and Corrosion Current in Acceleration Corrosion Testing under Corrosive Environment

This study conducted an acceleration corrosion test based on ASTM G85-19 standards to evaluate the durability of both steel and paint-coating. The objective was to assess the relative corrosive deterioration based on variations in the corrosive environment. In the ASTM G85-19 test method, we systematically altered the concentration of chloride and (NH<sub>4</sub>)<sub>2</sub>SO<sub>4</sub> to simulate different corrosive environmental conditions. The mean corrosion depth of the steel specimens was determined by quantifying weight throughout the acceleration cycle. Additionally, we measured the corrosion current output using the ACM sensor to validate the corrosive environmental condition corresponding to different acceleration cycle scenarios. Analysis of the results from the acceleration corrosion test revealed significant variations. The mean corrosion depth exhibited a range of 1.1 to 2.7-fold change, while the corrosion current showed fluctuations ranging from 1.2 to 5.7 times, contingent upon the conditions of the acceleration test, including the quantities of chloride and (NH<sub>4</sub>)<sub>2</sub>SO<sub>4</sub> present.

The investigation of Sn corrosion on Mo meshes under the irradiation of high-flux hydrogen plasma

Liquid-metal divertor consisting of liquid Sn and Mo meshes would face high-flux plasma environments during service. In this work, the Sn corrosion behaviors on initial and pre-irradiated Mo meshes under hydrogen plasma irradiation were investigated to evaluate the reliability of the porous structure. According to the analysis and computation of XRD spectrum, the sub-grain size of the initial meshes would continuously grow during the corrosion process. The SEM images showed that after corrosion, the appearance and disappearance of prismatic Mo grains occurred alternately with the increase of plasma fluence. The thicknesses of corroded wires in the longitudinal and transverse directions displayed a similar repeatable change. In comparison to initial meshes, surface sub-grain growth and damage induced by the pre-irradiation treatment would result in differences in the corrosion process under hydrogen plasma irradiation. The pre-irradiated surface Mo grains with obvious grain boundaries were first dissolved to pebble-like Mo particles by liquid Sn and then stripped from the surface after corrosion. Sub-grain size was reduced from 72.5 nm to 41.1 nm at the fluence of 1.07 × 1026 ions/m2, which was inverse to the increasing phenomenon of the initial sample under same corrosion conditions. Additionally, the corrosion phenomenon, i.e., the presence and subsequent disappearance of prismatic Mo grains, occurred similarly on the surface of pre-irradiated samples. Based on the analysis of initial and pre-irradiated surface morphologies and wire thickness, Mo grains might go through an onion-peeling-like cycle of growth and fracture during the corrosion process. Besides, the wire thicknesses of all pre-irradiated Mo meshes were slightly less than that of the initial samples under the same corrosion conditions. Somehow, the comparative result reflected that the pre-irradiated samples were corroded more severely. Thus, the pre-irradiation of hydrogen plasma in this work would weaken corrosion resistance of Mo meshes in liquid Sn.

The Effects of Corrosion and Fire Damage on the Steel-Bolted T-Section Connections Used in the Steel Construction.

The most common type of connection in steel structures is the T-section connection. Steel structures can be damaged due to environmental effects such as earthquakes, fires, corrosion, etc., in real applications used in industry. Therefore, in this study, the corrosion and fire condition effects that occur in the T-section connection on the behavior of the connection zone were investigated. The study was carried out with 18 T-section connections with various corrosion (hydrochloric acid and sulfuric acid) in different layers at 5, 10, 15, and 20% corrosion levels, and fire (ISO834) conditions after corrosion have been evaluated and compared. T-section-bolted joints examined in the study were produced using IPE300 standard profiles. In the first part of the study, the behavior of the 18 T-section connections under an axial tensile load has been determined experimentally. The second part created a finite element model with the ABAQUS program for all models. It was seen that the finite element model analysis results converged with the results obtained as a result of the experimental study. As a result, compared to H2SO4 corrosion, HCl corrosion has little effect on the load-deformation characteristics of the connections. Also, if corrosion specimens are exposed to fire, then the connections will change from semirigid to hinged.

Corrosion Behaviour Modelling Using Artificial Neural Networks: A Case Study in Biogas Environment

The main objective established in this work was to develop a model based on artificial neural networks (ANNs) to predict the corrosion status of stainless steel involved in biogas production, analyzing the influence of the material composition and the breakdown potential value. To achieve this objective, an ANN model capable of predicting the corrosion status of the material without the need to perform microscopic analysis on the material surface was proposed. The applicability of the corrosion models was verified via the experimental data considering different factors such as stainless steel composition, biogas environments simulated by artificial solution, temperature, surface finish, and the breakdown potential of the passive layer of stainless steel obtained from electrochemical tests. The optimal prediction performance shown by the model in terms of specificity and sensitivity values were 0.969 and 0.971, respectively, obtaining an accuracy of 0.966. Furthermore, analyzing the influence of the breakdown potential on corrosion modelling, an alternative model was presented capable of predicting the corrosion status automatically, without the need to resort to electrochemical tests for new conditions. The results demonstrated the utility of this technique to be considered in design and maintenance planning tasks for stainless steel structures subjected to localized corrosion in biogas production.

Corrosion Performance of Sn-Doped AlCrFeNiMn High-Entropy Alloy Synthesized via Arc-Melting Technique

Failure of materials such as steels during engineering applications can result in economic harm; hence, developing new corrosion-resistant materials is critical. In this work, high-grade powders of Al, Cr, Fe, Mn, and Ni were used to synthesize an equimolar AlCrFeNiMn high-entropy alloy (HEA) for potential chemical industry application. The cast alloy's properties were further altered by the addition of 1at%, 3at%, and 5at% tin (Sn) as alloying additives. To assess the impact of Sn on the alloy's resistance to corrosion, potentiodynamic polarization tests were conducted in various acidic and basic environments. Several surface inspection techniques, including scanning electron microscopy (SEM), optical microscopy (OPM), X-ray diffractrometry (XRD), and energy-dispersive X-ray spectroscopy (EDS), were employed to examine the morphological changes and elemental composition of the alloy after it was subjected to corrosive conditions. The nano-indentation machine was used to analyze the materials' nanohardness. TGA analysis was also performed to determine how Sn additions affected the AlCrFeNiMn HEA’s thermal stability. In 0.5 M HCl solution, the Sn-doped alloys demonstrated good corrosion resistance. Their exposure to 0.5 mol/L H2SO4 solution, on the other hand, found to be deleterious to their electrochemical stability. The weight loss of 5 at% Sn-doped samples in 0.5 M H2SO4 solution was found to be substantially reduced. The mass of all the samples stayed constant in 3.5 wt% NaOH solution.

A probabilistic assessment methodology for pitting corrosion condition of offshore crude oil pipelines

Pitting corrosion is considered as the main degradation form and poses a serious threat on service life of offshore crude oil pipelines. The prediction and assessment of pitting corrosion is challenging due to the uncertainties in pitting corrosion growth. This paper presents a probabilistic methodology based on Bayesian Network (BN) and Hierarchical Bayesian Analysis (HBA) to estimate the pitting corrosion condition of offshore crude oil pipelines. To capture the uncertainties in pitting corrosion growth, Continuous BN model is utilized to simulate the temporal evolution of pitting corrosion depth. HBA is employed to evaluate the time-varying probability of pitting corrosion failure. A case study is implemented to illustrate the methodology. It is observed that the methodology can serve as a useful tool for integrity management of offshore crude oil pipelines subject to pitting corrosion.

Mechanism of Mo content on improving the high-temperature corrosion performance of APS sprayed Ni-clad Al coatings in simulated biomass corrosion condition

The study examined the impact of varying molybdenum content (0 %, 5 %, and 10 % wt) on the high-temperature corrosion resistance of APS-sprayed Ni-clad Al coatings. The coatings were exposed to a simulated biomass-firing environment with pure KCl deposition at 600 °C for 168 h, and a mixed gas containing 15 % water vapor was passed through. The findings revealed that increasing Mo content improved the coating's high-temperature corrosion resistance. The coating with 10 % Mo displayed a continuous layer of Ni and Al oxides on its surface, while KCl was concentrated in the Mo region. Based on the experimental results, a mechanism for how the presence of Mo element contributes to the high-temperature corrosion resistance of NiAl coatings was proposed.

Influence of accelerated corrosion on Al/steel RSW joints by in situ compression tests

The present work investigates the correlations between galvanic corrosion, intermetallic compound (IMC) formation, and the input of welding energy with respect to the initiation and propagation of micro-cracks in micropillars of resistant spot welding (RSW) joints between aluminum (Al) and steel. The present results indicate that, in the high welding energy region, Al was corroded first after 26 cycles of corrosion, and Al5Fe2 IMC was corroded after 72 cycles of corrosion due to its high corrosion potential predicted by the calculations based on density functional theory (DFT) in terms of the Nernst equation. In comparison with the high welding energy region, less corrosion was observed in the middle welding energy region due to the thinner Al5Fe2 IMC layer, a lower amount of Al13Fe4 IMC in the Al matrix, and lower residual stress. Mechanical properties at different locations after various corrosion conditions were obtained using in situ compression tests, including the stress-strain responses and the strain rate sensitivity. The micropillars from the high welding energy region have a higher average yielding stress due to the thicker IMC layer than those from the middle welding energy region. The yielding stress decreases gradually with increasing corrosion cycles. Three conditions for crack initiation and propagation have been identified: firstly, for pillars from the high welding energy region before corrosion or the middle welding energy region (before or under the minimal corrosion conditions), the cracks initiate within the IMC layer; secondly, for pillars from the high welding energy region after 26 cycles of corrosion (under the moderate corrosion condition), cracks propagate at the Al/IMC interface; finally, for pillars from the high welding energy region after 72 cycles of corrosion (under the severe corrosion condition), the cracks initiate at the IMC/steel interface.

Crack growth in high strength mooring line steel under variable amplitude loading

Mooring lines are of key importance for the safe and reliable operation of numerous floating offshore structures. Due to the constantly changing wind and wave conditions acting on such structures, any fatigue crack growth in a mooring line will occur under cyclic loading of distinctly variable amplitude. This paper considers a long-term load history for mooring lines on a North Sea offshore platform. For fatigue testing purposes, a characteristic load sequence representing the actual load history in a condensed and simplified form is developed and presented. Fatigue crack growth rate test results for a grade R4 high strength mooring chain steel subjected to this variable amplitude load sequence is furthermore presented, including tests performed in air as well as under free corrosion conditions in artificial seawater. Based on comparison testing performed under variable- and constant amplitude conditions, the validity of a linear damage rule hypothesis for stable crack growth under the characteristic load sequence is investigated. This damage rule converts the load spectrum to an equivalent constant load range, making it a potentially useful tool for estimating fatigue crack growth in mooring chains when test data for a representative characteristic load sequence are unavailable. Results from the comparison testing are used to show that under stable fatigue crack growth conditions, while subjected to the characteristic load sequence developed for this offshore platform, the linear damage rule can be a reasonable assumption.

Utilizing Data-Driven Methods to Predict the Fatigue Life of Cement Concrete Considering Corrosive Environmental Factors

The primary objective of this study is to assess the fatigue resistance of cement concrete when exposed to corrosive environments. To achieve this, experimental results from high-cycle fatigue (HCF) and low-cycle fatigue (LCF) tests conducted on cement concrete samples subjected to various corrosive conditions were used. Various data-driven techniques, including multiple linear regression (MLR), Taguchi sensitivity analysis (TSA), and response surface method (RSM) were utilized. The aim was not only to identify the most influential parameter affecting fatigue life but also to offer a simpler and cost-effective alternative to experimental approaches. Consequently, two key parameters related to the corrosive environment: pH value and immersion time, along with the cyclic force applied to the concrete samples as input variables across different approaches were considered. The number of cycles until sample failure regarded as the output variable in all analyses. Furthermore, the analyses were conducted with the assumption that longer fatigue life is preferable. The findings revealed that the fatigue life of Portland cement concrete consistently decreased with increasing immersion time. Notably, the pH value emerged as the most significant parameter, while the other two factors exhibited equivalent impacts.