Corrosion Damage Research Articles

A novel strategy to improve the corrosion resistance of SiCf/SiC composites in high-temperature combustion environments by cooperation of self-healing SiBCN and high-stability Yb2Si2O7

How to improve the resistance to water-oxygen-salt corrosion of SiCf/SiC composites is vital to their long-term service in the advanced aero-engines or gas turbines. SiCf/SiC-SiBCN-Yb2Si2O7 (SSY) self-healing composites were exposed to combustion environments at 1200–1350 °C for a long time up to 100 h. The dissolution of solid Yb2Si2O7 into low-viscosity glassy oxides derived mainly from oxidation of SiBCN leads to the formation of stable Yb2Si2O7-contianing multi-phase silicate which can inhibit the diffusion of corrosive media and alleviate corrosive damage of composites. After corrosion in H2O/O2/Na2SO4 at 1200 °C and 1350 °C, the strength retention rates of SSY are 96 % and 88 %, respectively, (6.4 ± 0.9)% higher than those of SiCf/SiC-SiBCN (SS), due to the good cooperative protective effect of SiBCN-Yb2Si2O7. However, the insufficient dissolution of Yb2Si2O7 causes the formation of plenty of solid/liquid interfaces conductive to the diffusion of corrosive media in H2O/O2 at 1200 °C and 1350 °C. As a result, the retention rates of flexural strengths of SSY are 100 % and 91 %, respectively, (2.5 ± 0.5)% lower than those of SS.

Weather-Related Combined Effect on Failure Propagation and Maintenance Procedures towards Sustainable Gas Pipeline Infrastructure

Weather-related events are among the major causes of failure propagation in natural gas pipeline infrastructure. The interaction between multiple natural-force factors, such as temperature, precipitation, and wind, and their unpredictable simultaneous occurrence can intensify the vulnerability of pipeline infrastructure, increasing the likelihood of leaks, ruptures, and mechanical damage. This paper provides a comprehensive review of the combined effect of weather-related events on the failure propagation of pipelines, focusing on the impact of weather-related external force factors and climate change on sustainable pipeline integrity, including corrosion, erosion, and mechanical damage. Additionally, the paper examines various maintenance policies and strategies that can be implemented to mitigate the impact of weather-related failures. The review highlights gaps in existing knowledge and future research directions to enhance the understanding of weather-related failure propagation in natural gas pipeline infrastructure. This paper provides insights into the challenges and opportunities for improving the resilience and sustainability of pipeline infrastructure to weather-related failures.

Root cause analysis of corrosion failure of a firefighting pipeline

This is a specific case of corrosion damage to underground pipelines in the Arabian Gulf region caused by stray current corrosion. The damage occurred in a fire protection piping system connected to a sprinkler system. The investigation revealed that the corrosion surface morphology was localized and had historically occurred in the same location of previously failed pipe sections. Despite previous attempts to correct the problem, the cause remained undetected and undetermined. It was determined that the failure was due to electromagnetic forces generated by the proximity of high AC and DC voltages. Specifically, the stray current corrosion was caused by interference from electrical cables, including a high-voltage cable and a ground discharge from electrical electrodes. To prevent future failures, it was strongly recommended that all existing conduit pipes in the affected section be insulated with double-layer insulating tape, which has high impedance and dielectric properties.

Characterization of Al/B4C–Y2O3 hybrid composites produced by vacuum hot pressing combined with Al2O3–Y2O3 interaction

In this study, the Al/B4C/Y2O3 hybrid composites were produced by Al2O3 and Y2O3 interaction via hot pressing. Moreover, the influence of Y2O3 on the properties of Al/B4C 10 wt% was investigated. The hot pressing was performed at 600 °C with pre-oxidized aluminium powder to produce the composites. The microstructure analyses revealed that Al/B4C/Y2O3 hybrid composite production was achieved by Al2O3 and Y2O3 interaction, and the Y4Al2O9 (YAM) phase was obtained in the Al–B4C/Y2O35 % sample. The Y2O3 addition increased the porosity content of the Al/B4C structure. However, wear rate and corrosion resistance of the Al/B4C were enhanced owing to the presence of Y2O3. The wear rate of Al/B4C was reduced from 26.55·10−7 cm3/Nm to 5.68·10−7 cm3/Nm at 15 N test load. The increasing Y2O3 content and the formation of the Y4Al2O9 decreased the corrosion rate of the Al/B4C fom 0.0179 mm/year to 0.0051 mm/year. Also, corrosion damage was shifted from the matrix to the reinforcement zone in Al–B4C/Y2O35 % sample, and the aluminium was protected owing to the presence of Y2O3 and Y4Al2O9.

Enhancing acoustic emission analysis for corrosion damage detection in reinforced concrete by k-nearest neighbors method

The Acoustic Emission (AE) method is considered a significant tool for detecting damage in reinforced concrete structures caused by reinforcement corrosion. However, processing a large amount of AE data using traditional analysis methods is time-consuming. Therefore, integrating machine learning (ML) techniques into this process offers a more logical and effective solution to expedite data analysis and enhance damage detection accuracy. This study aims to train an ML model for detecting corrosion damage in reinforced concrete structures using an AE dataset. In pursuit of this goal, it seeks to enhance source localization that contributes to identifying crack patterns through signal-based analysis methods. AE data obtained from a reinforced concrete structural element subjected to accelerated corrosion testing in laboratory conditions have undergone detailed analyses with the ML model. In this context, an ML model capable of learning signals with various wave characteristics and parameters has been successfully integrated into the source localization algorithm, significantly improving AE source localization outcomes. Furthermore, this method is critical for structural safety as it enables the early detection of reinforcement corrosion and precise localization of cracks. The integration of this machine learning model with AE data serves as a valuable tool developed for more effective monitoring of damage in structures.

Development of a condition monitoring of heat exchangers for corrosion progress and coolant condition

The transport sector, and thus also rail transport, needs to be completely decarbonised by 2050 at the latest. Considering the long service life of rail vehicles, this goal means enormous innovation and growth potential for the vehicle and supplier industry of railway technology in the coming years. This contribution presents the first results of an R&D project to reduce the total cost of ownership of passenger and freight rail vehicles. The reduced life cycle costs can be achieved over the operating life, among other things, with condition monitoring approaches for critical components of cooling systems to enable diagnosis-based maintenance. Based on guided elastic waves, an integrated system is being developed to analyse the depth and position of corrosion damage to heat exchangers in rail vehicles. This method is to be supplemented by a refractive index sensor integrated in the coolant circuit which can be used to derive influences of the coolant condition on corrosion. First, an acoustic measuring technique was put into operation. Suitable piezoelectric transducers were selected and test measurements, including the introduction of artificial damages, along different paths on a representative heat exchanger were carried out and evaluated. Measurement signals can be received over different distances, and a monitoring of larger areas of the heat exchanger seems possible. For the development of the monitoring of the coolant, plasmonically active sensor substrates with a gold nanostructure were produced and installed in a measuring flow cell. In laboratory tests, concentrations of water-coolant mixtures could be distinguished with the refractive index sensor. In the future, the refractive index sensing will be carried out by means of bypass flow measurement. Since the coolant is pumped in a circuit, the sensor system can be attached to one of the inlet/outlet lines.

INVESTIGATION OF STRUCTURAL AND MECHANICAL PROPERTIES OF TUBING STEELS

The study of the structural and mechanical properties of tubing steels used in wells at oil and gas condensate fields is of particular interest due to the resource intensity of these systems and the high cost of their repair and restoration. Tubing is operated under conditions of increased loads under the influence of its own weight, internal pressure and constant contact with highly aggressive media. As a result of simultaneous exposure to corrosive media and operational loads, tubing is the most consumable downhole material. The destruction and, as a result, the breakage of the tubing suspension occurs as a result of mechanical abrasion and cracking of the pipe body, the development of fatigue cracks in the thread, etc. Contact with aggressive agents of the extracted fluid and reservoir waters leads to various types of corrosion damage: ulcerative, pitting, corrosion fatigue, corrosion cracking, meza corrosion, biocorrosion, etc. Corrosion foci are localized on the inner and outer surfaces of pipes. The problem is complicated by the increased content of carbon dioxide (CO2), hydrogen sulfide (H2S), as well as the presence of various bacteria in oil and gas fields.This article is devoted to the study of the mechanical characteristics and microstructure of tubing steels that were in operation under conditions of complicating factors and highly aggressive corrosive environment. Tubing pipes Ø73x5.5 of strength group E. were tested. The following research methods were carried out: visual inspection; determination of the chemical composition of steel; determination of hardness; uniaxial tensile test; optical microscopy.As a result of the tests, quantitative characteristics of the mechanical properties of the steels were obtained. A significant decrease in the hardness, tensile strength and yield strength of steel has been established under prolonged exposure to complicated operating conditions. Metallographic studies have established the contamination of steels with silicates of various shapes, amounting to 3 and 2 points according to GOST 1778. Microstructural studies have been carried out. The fine-grained ferrite-carbide structure of steels has been revealed. This structure corresponds to the heat treatment mode: quenching followed by tempering.

ASSESSMENT OF THE CORROSION-MECHANICAL PROPERTIES OF THE LEFT MATERIALS AND FORECASTING THE SAFETY OF GAS TURBINE PARTS

Purpose. Determination of the possibility of using the temperature-time parametric dependences of Miller-Larson, Manson-Haferd, and Sherby-Dorn for long-term prediction of the strength characteristics of parts subjected to oxidation and high-temperature sulfide-oxidation effects. Research methods. Long-term strength studies were performed on samples of ВЖЛ-12У and ЗМІ-3У alloys in synthetic ash (66.2 % Na2SO4, 20.4 % Fe2O3, 8.3 % NiO, 3.3 % CaO, 1.8 % V2O5) and an oxidizing environment at temperatures of 800 °C and 850 °C. The Miller-Larson, Manson-Haferd, and Sherby-Dorn temperature-time parametric dependences were used to predict the tensile strength of materials in an oxidizing and corrosive environment. The microstructure of the samples was studied using an optical microscope MIM-8M. Results. The results obtained indicate a high level of corrosion resistance of ЗМІ-3У samples at 800 °C and 850 °C and the possibility of determining the tensile strength of the material for a period of 1000, 5000, and 10000 hours by the calculation method. Tests of ВЖЛ-12У alloy samples in synthetic ash showed a discrepancy between the experimental time to fracture and the calculated value, regardless of the parametric method, which indicates a direct dependence of long-term strength on the degree of corrosion damage to the surface of the samples. Scientific novelty. The possibility of using the Miller-Larson, Manson-Haferd, and Sherby-Dorn temperature-time parametric dependences for long-term prediction of the strength characteristics of parts in an oxidizing environment has been confirmed. In a sulfide-oxide environment, the use of parametric methods to determine strength characteristics for up to 10,000 hours is possible only for corrosion-resistant alloys. Intensive corrosion damage to ВЖЛ-12У alloy leads to accelerated deformation, which limits the use of temperature and time dependencies for effective prediction of the time of failure of parts made of this material. Practical value. Determining a reliable method for predicting the strength characteristics of heat-resistant alloys in an oxidizing and corrosive environment allows reducing the time and financial costs of conducting lengthy field studies.

Экспериментальная оценка влагостойкости полимерных композиционных материалов, используемых для ремонта машин

The results of corrosion tests of metal parts with through defects are presented, for the elimination of the defects an epoxy compound containing various types of fillers was used. Dispersed (aluminum powder and carbon-containing powder) and fibrous (glass and carbon fabrics) materials were applied as fillers. It has been established that the minimum number of corrosion damages was found in samples recovered with an epoxy compound (ED-20 resin and PEPA hardener) with aluminum powder as a filler and reinforced with fabric fillers.

Diagnostics and Prognostics of Pitting Corrosion in Large Civil infrastructure Using Multi-scale Simulation and Machine Learning

Corrosion, particularly pitting corrosion, represents a prominent form of deterioration in large infrastructure, characterized by its gradual and continuous capacity-reducing nature. As structures age, the need for assessing and monitoring corrosion status becomes increasingly crucial for system life-cycle management and optimal maintenance. However, the intricacies of the corrosion process pose challenges to effective diagnosis and prognosis. These challenges include the insufficient integration of mechanical stress into existing corrosion simulations, the computational intensity of most physics-based corrosion simulations hindering probabilistic studies and real-time predictions, and the difficulty in detecting pitting corrosion due to its localized nature, making it impractical to measure individual pits. This paper introduces a comprehensive prognosis and diagnosis framework applied to a miter gate case study. The framework seamlessly integrates multi-scale simulation, including mesoscale Phase-Field (PF) simulation and macroscale structural analysis, with Machine Learning (ML) methods to enable real-time corrosion diagnosis and prognosis. It facilitates efficient structural health monitoring (SHM) through a digital twin (DT) for corrosion damage. The core components of this framework encompass the development of multiscale simulation for simulating pitting corrosion in large structures, the construction of ML-based surrogate models to expedite simulations, image-based diagnosis, and the updating engine for prognosis.

FORECASTING THE FINAL RESOURCE OF THE REINFORCED CONCRETE CHIMNEY PIPE OF THE COKE CHEMICAL PRODUCTION

A comprehensive study of the technical condition, corrosion processes, damage and load-bearing capacity of the reinforced concrete chimney pipe, which removes the gas-smoke mixture formed in the technological processes of coke-chemical production and is an aggressive environment, was performed. A methodology for predicting the remaining resource of the pipe structure has been developed. It was established that the damage that determines the ultimate resource is the collapse of the lining, after which active corrosion damage of the reinforced concrete structure occurs. An analysis of the composition and temperature-moisture regime of the aggressive medium was performed. It was established that it is gaseous, the most aggressive components of which are acid gases, the degree of aggressive action is moderately aggressive, possibly strongly aggressive. Corrosion of concrete progresses in a concentric front from the inner surface of the chimney to the outer surface at a rate of 1.2 to 4.8 mm/year. The corroded layer of concrete loses its strength and protective properties to the reinforcement. An analysis of the stress-strain state of the pipe taking into account corrosion damage was performed, the most heavily loaded dangerous zone and its structure were determined, and the limit values of the wall thickness and the depth of corrosion damage in this zone were determined, which ensure the fulfillment of the conditions for bearing capacity. Based on the values of the corrosion rate, the time to reach the limit state is determined. It is shown that without repair and protection measures, the remaining service life of the pipe does not exceed 11 years. It is recommended to carry out a major repair of the pipe as soon as possible with the elimination of damage and restoration of the lining, or no later than after 10 years to carry out the liquidation of the structure with the construction of a new one.

Progressive Collapse of Structural Systems Considering Force and Corrosion Damage

Progressive Collapse of Structural Systems Considering Force and Corrosion Damage

Mitigation of Steel Corrosion Threshold Utilizing Plant-Based Green Corrosion Inhibitors through Electrochemical Techniques

Corrosion of steel reinforcement is a major cause of deterioration in reinforced concrete structures. The corrosion process is influenced by the concrete-steel interface, with the alkaline concrete pore solution initially providing passivation. However, ingress of aggressive substances like chlorides can disrupt the passive layer, initiating active pitting corrosion above a threshold level often taken as 0.4% chloride by cement weight. Once the chloride threshold is exceeded, corrosion propagation depends on oxygen and moisture availability. The resulting rust formation causes expansive cracking and spalling of the concrete cover. Corrosion damage can be mitigated through use of inhibitors like calcium nitrite though high dosages impair concrete strength. Recently, plant-based organic compounds have shown promise as green corrosion inhibitors. The corrosion behavior of steel in concrete can be evaluated through impressed accelerated corrosion testing along with electrochemical techniques like half-cell potential mapping and resistivity measurements. These allow assessment of the probability of corrosion and corrosion rate. Techniques like linear polarization resistance and electrochemical impedance spectroscopy can also quantify instantaneous corrosion rate. Proper structural condition assessment and repair using both conventional and green inhibitors is crucial to control steel corrosion, maintain service life and ensure safety. Further research is needed on green corrosion mitigation methods and advanced non-destructive testing techniques.

Effect of Corrosion Inhibitors on Bond Strength of Reinforced Concrete Structures

Corrosion of steel reinforcement is a major factor affecting the durability and strength of reinforced concrete structures. This study investigated the influence of plant-derived corrosion inhibitors, applied as coatings, on the bond strength between reinforcing steel and concrete. Thirty-six 150 mm concrete cubes with 12 mm diameter embedded steel bars were prepared and divided into uncoated, corrosion inhibitor coated, and control groups. The samples were immersed in 5% sodium chloride solution over 360 days to accelerate corrosion. Pull-out testing measured the bond strength and failure load. The corroded samples showed 31-26% lower bond strength and 82-87% higher maximum slip than controls, indicating corrosion damage at the steel-concrete interface. However, inhibitor-coated samples displayed 24-36% higher bond strength and 42-43% lower maximum slip versus corroded samples. Although the coatings did not fully restore original bond strength, this demonstrates their effectiveness at protecting bond properties. Microscopic analysis revealed non-uniform, localized corrosion preferentially initiated at steel defects. Statistical correlations confirmed the direct relationship between steel weight loss and reductions in post-corrosion rebar weight due to material loss. While nominal rebar diameters showed minimal differences between sample types, localized diameter reductions and cross-sectional area increases in corroded samples highlighted discrete corrosion effects. These were mitigated in coated samples. Together with direct weight loss measurements, this proves corrosion occurred in unprotected samples. Overall, the significant recovery of bond strength, slip resistance, diameter, area, and weight in coated samples validates the success of the natural corrosion inhibitors in reducing steel deterioration and interface degradation. The results provide new insights on optimizing inhibitor coatings to maximize corrosion protection for reinforced concrete structures.

Flexural Strength of Reinforced Concrete Structures Exposed to Corrosive Media

This study investigated the effect of corrosion on the flexural behavior and midspan deflection of reinforced concrete beam members. Control, corroded, and resin-coated concrete beam specimens were tested to determine their failure load, midspan deflection, rebar diameter measurements, and mechanical properties. The results showed that corrosion significantly reduced the flexural strength and increased the midspan deflection of beams due to weakening of the reinforcing steel. The average failure load of corroded beams decreased by 25.73% compared to the control beams. Similarly, the average midspan deflection of corroded beams increased by 103.8% over the control beams. Measurements of rebar diameters before and after corrosion revealed reductions of up to 0.87% in corroded samples, substantiating corrosion-induced thinning. Additionally, mechanical properties testing showed decreases in ultimate tensile strength, yield strength, and strain ratio while increasing ductility for corroded rebars. Resin coating prevented much of the strength loss and provided protective benefits near that of the control specimens. The relationship between failure load, midspan deflection, diameter measurements, mechanical properties and corrosion damage was investigated through analytical comparisons. Corroded samples consistently demonstrated lower failure loads, higher deflections, reduced diameters and strengths versus controls. Conversely, coated samples performed similarly to controls, validating the coating's effectiveness. This research quantitatively confirms literature reports that corrosion degrades reinforced concrete through weakening of rebar-concrete bond and steel deterioration over time if left unprotected. The findings emphasize the importance of mitigating corrosion to ensure structural integrity, safety and durability of reinforced concrete infrastructure.

Corrosion inhibition performance of RNC-n on aluminum alloy surface in alkaline solution

The corrosion inhibition behavior of glycine surfactants with different carbon chain lengths (RNC-n, n = 8, 12, 14) of AA2024-T3 aluminum alloy in 0.01 mol·L−1 NaOH solution was investigated. The weight loss and electrochemical methods, XPS, SEM/EDS techniques, quantum chemical calculations, and molecular dynamics simulations were used for studying the corrosion inhibition properties, adsorption behavior, and corrosion inhibition mechanism. When the maximum solubility of 0.01 mol·L−1 was achieved, the inhibition effectiveness of RNC-8 reached 90.55 %. Both RNC-12 and RNC-14 exhibited inhibitory efficiencies of 92.81 % at 0.005 mol·L−1 and 91.83 % at 0.0005 mol·L−1. RNC-n was shown to be an anodic corrosion inhibitor, since its impact on the anodic reaction was larger than on the cathodic one. RNC-n was able to successfully adsorb on the aluminum surface and form a protective film, which hindered further corrosion damage of the aluminum by the alkaline solution. In addition, the adsorption sites of RNC-n molecules were analyzed, and it was found that the adsorption sites of the corrosion inhibitor were mainly in the carboxyl group. Therefore, this paper can provide some theoretical support for the protection of aluminum alloys against corrosion in alkaline medium.

Corrosion behavior, metal ions release and wear resistance of TiN coating deposited on SLM CoCrMo alloy by magnetron sputtering

In this study, the TiN coating was successfully deposited on selective laser melting (SLM) CoCrMo alloy via magnetron sputtering technique. The TiN coating microstructure and thickness were studied by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The electrochemical corrosion behavior, metal ions release and wear resistance of the SLM CoCrMo sample with and without TiN coating was compared. The results showed that there was some macroparticles and pores on the TiN coating surface and the TiN coating thickness was about 1.44 μm. The TiN coating helped the SLM CoCrMo sample to reduce the corrosion current density from 19.1 nA/cm2 to 8.12 nA/cm2 and improved the corrosion resistance but not significantly. Then, an explanation of the corrosion resistance changes of the TiN coating was given. In addition, the TiN coating could prevent the metal ions release such as Co, Cr and Mo of the SLM CoCrMo sample at short time immersion but lost the protecting effect at long time immersion due to the corrosion damage of the TiN coating. Furthermore, compared to the SLM CoCrMo sample, the TiN coating was conductive to improving the wear resistance only at lower normal load (5 N) but had similar wear resistance at higher normal load (10 N and 30 N). The reason was mainly attributed to the thinner TiN coating thickness and higher load led to the failure of the TiN coating.

Green smart multifunctional wooden roofs enabled by single-step hydrophobic laser-induced graphene fabrication

Global warming, contributing to the worsening climate crisis, has led to more frequent heavy snowfall and rainfall. This causes corrosion, mold, and structural damage to roofs, which shortens the roofs' lifespan and potentially creates safety hazards. Addressing these challenges, we propose an approach to develop a multifunctional roof crucial for proactive adaptation to extreme weather. In this article, we present hydrophobic laser-induced graphene (LIG) onto wood in a single-step process using femtosecond-laser-direct-writing (FsLDW) technology in ambient air without additional chemical treatment. This hydrophobic LIG, showcasing a high electrical conductivity of 10.0 Ω·sq⁻1 and a high contact angle of 148.8°, seamlessly integrates onto roofs, creating cost-effective, fast, eco-friendly, and smart roofing solutions. The hydrophobic surface of these LIG electrodes incorporates a heating function of LIG showcasing their versatility in providing waterproofing, drying wood, and facilitating de-icing functions. This eco-friendly invention, reliant solely on laser patterning on wood, not only extends roof lifespan but also relieves concerns about electronic waste and recycling, promising the integration of green, smart, and sustainable roofing solutions.

Effects of High Al Content on the Phase Constituents and Thermal Properties in NiCoCrAlY Alloys.

MCrAlY (M = Ni and/or Co) metallic coatings are essential for the protection of hot-end components against thermal and corrosion damage. Increasing the Al content is considered a feasible solution to improve the high-temperature performance of MCrAlY coatings. In this paper, the effects of high Al contents (12-20 wt.%) on the phase constituents and cast microstructures in MCrAlY alloys were studied by high-energy X-ray diffraction and electron microscopy techniques combined with phase equilibria calculations. High Al content improved the stability of β, σ, and α phases. Meanwhile, an evolution of the cast microstructure morphology from a dendrite structure to an equiaxed grain structure was observed. The thermal properties were analyzed, which were closely related to the phase constituents and solid-to-solid phase transitions at evaluated temperatures. This work is instructive for developing high-Al-content MCrAlY coatings for next-generation thermal barrier applications.

Oxygen-enhanced dissolution corrosion of austenitic stainless steel 316 L in static lead-bismuth eutectic at 500 °C

The corrosion process of 316 L austenitic stainless steel in liquid lead-bismuth eutectic at 500°C with dissolved oxygen concentrations ranging from below 10−11 to 10−5 wt% was investigated. The maximum dissolution corrosion damage and the highest oxygen consumption during the experiments occurred at intermediate dissolved oxygen concentrations (10−7 and 10−6 wt%). An assumption of a governing role of Fe3O4 equilibrium and diffusion-limited processes on the steel surface explains quantitatively this observation. The proposed mechanism suggests that oxygen-enhanced dissolution is a result of the combination of solid steel dissolution and the oxidation of dissolved steel constituents in the liquid metal bulk.