Corrosion Monitoring Techniques Research Articles

Study on the initial corrosion characteristics of weathering steel bridges with corrugated steel webs

In this study, the characteristics and influencing factors of the early corrosion evolution process of the weathering steel (WS) bridge in northwest China were examined, revealing the seldom-studied corrosion evolution law of the corrugated web of weathering steel. The corrosion losses and average corrosion thickness of WS bridge components were measured and evaluated. The results revealed that compared with traditional flat steel webs, the corrosion of corrugated steel webs was enhanced in the vertical direction and at the wave peak, and resulted in a more complex corrosion pattern. The trend of the rust layer on the inner and outer surfaces of the box girder is related to the stage characteristics of the corrosion products. The appearance of microscopic characteristics of the rust layer is periodic, with the rust layer thickness, colour, and particle size varying with the bridge’s location. The development of the corrosion pit followed a lognormal distribution, and the corrosion rate was balanced in the radial and depth directions. These results can serve as a basis for designers or inspectors to design WS bridge structures, select correct corrosion allowances, and improve corrosion monitoring and detection techniques.

Influence of Soda and Kraft lignin in polyurethane coatings for the corrosion protection of mild steel in 3.5 % NaCl solution

This study highlights the potential of coconut shell biomass waste-derived lignins (CSL) as corrosion inhibitors to reinforce the coating properties of polyurethane. The utilization of CSL involves a green approach to prepare eco-friendly metallic coatings. Herein, lignin was extracted via Kraft and Soda pulping processes. The present findings indicated that the percentage yield of Soda lignin (SL) (26.43 ± 0.75 %) was significantly higher than that of Kraft lignin (KL) (8.52 ± 0.39 %). Electrochemical impedance spectroscopy and potentiodynamic polarization corrosion monitoring techniques were used to evaluate the anticorrosive performance of modified polyurethane coatings on mild steel exposed to 3.5 % NaCl solution. In this study, doping concentration of 5 wt% KL and SL into polyurethane attained the optimum anticorrosion performance. The surface conditions of uncoated and coated mild steel substrates were investigated through scanning electron microscopy/energy dispersive X-ray (EDX) analysis, salt spray and adhesion tests. EDX analysis demonstrated that polyurethane added with 5 wt% doping concentration of SL contained the highest content of Fe (86.05 wt%) compared to 5 wt% KL which contained 79.64 wt% of Fe, whereas neat polyurethane coating contained 75.43 wt% of Fe. Hence, enhanced corrosion protection of polyurethane through the addition of CSL, particularly SL, possesses a viable and an effective green approach to utilize coconut shell biomass waste for the application as a potential corrosion inhibitor in organic coatings.

Corrosion Monitoring Techniques in Subcritical and Supercritical Water Environments

A series of advanced equipment exposed to sub-/supercritical water environments at high temperatures, high pressures, and extreme water chemistry with high salt and dissolved oxygen content faces serious corrosion problems. Obtaining on-site corrosion data for typical materials in harsh environments is crucial for operating and maintaining related equipment and optimizing various corrosion prediction models. First, this article introduces the advantages and disadvantages, usage scenarios, and future development potential of several in situ monitoring technologies, including ultrasonic thickness measurement, the infrared thermography method, microwave imaging, eddy current detection, and acoustic emission. Considering the importance of electrochemical corrosion data in revealing microscale and nanoscale corrosion mechanisms, in situ testing techniques such as electrical resistance probes, electrochemical corrosion potential, electrochemical impedance spectroscopy, and electrochemical noise that can be applied to sub-/supercritical water systems were systematically discussed. The testing platform and typical data obtained were discussed with thick and heavy colors to establish a mechanical prediction model for corrosion behavior. It is of great significance to promote the development of corrosion monitoring techniques, such as breaking through testing temperature limitations and broadening the industrial application scenarios and maturity.

Non-destructive techniques for corrosion detection: A review

Corrosion detection (CD) has become a high priority in chemical industries, defense and transportation sectors to extend the life of existing or new systems while ensuring the safety of the existing components and reducing downtime to minimise economic losses. Here, this article is aimed to review and discuss non-destructive techniques used widely in the industry to detect, monitor and repair corrosion problems early on. The comprehensive review provides a detailed discussion, a functional mechanism, advantages and disadvantages of crucial non-destructive CD techniques widely used in the industry, helping the reader choose the type of corrosion monitoring methods effectively. An extensive literature review of visual and optical testing techniques, acoustic emissions, eddy current, guided wave and equipment, infrared thermography, radiographic, microwave and millimeter wave, and terahertz imaging is discussed. The underlying mechanism, its merits and limitations, along with the usage scenario, is explained that can be related across different areas making it interdisciplinary research for corrosion monitoring techniques.

Review of Prediction of Stress Corrosion Cracking in Gas Pipelines Using Machine Learning

Pipeline integrity and safety depend on the detection and prediction of stress corrosion cracking (SCC) and other defects. In oil and gas pipeline systems, a variety of corrosion-monitoring techniques are used. The observed data exhibit characteristics of nonlinearity, multidimensionality, and noise. Hence, data-driven modeling techniques have been widely utilized. To accomplish intelligent corrosion prediction and enhance corrosion control, machine learning (ML)-based approaches have been developed. Some published papers related to SCC have discussed ML techniques and their applications, but none of the works has shown the real ability of ML to detect or predict SCC in energy pipelines, though fewer researchers have tested their models to prove them under controlled environments in laboratories, which is completely different from real work environments in the field. Looking at the current research status, the authors believe that there is a need to explore the best technologies and modeling approaches and to identify clear gaps; a critical review is, therefore, required. The objective of this study is to assess the current status of machine learning’s applications in SCC detection, identify current research gaps, and indicate future directions from a scientific research and application point of view. This review will highlight the limitations and challenges of employing machine learning for SCC prediction and also discuss the importance of incorporating domain knowledge and expert inputs to enhance the accuracy and reliability of predictions. Finally, a framework is proposed to demonstrate the process of the application of ML to condition assessments of energy pipelines.

Using Lignin and Tannin as Green Corrosion Inhibitors for Carbon Steel Petrolum Tanks

The best strategy for combating corrosion is verified by recent studies that employ organic green corrosion inhibitors isolated from plant extracts that are biodegradable, environmentally friendly, suitable priced, and safe. This current research conducted various experiments on Kraft lignin extracted from Iraqi date palm fronds base (DPFB) and tannin to inhibit corrosion. The corrosion monitoring technique includes the weight loss method and surface analysis by optical microscope. The extracted lignin was characterized using 13CNMR. The results showed clear evidence of Kraft lignin’s and tannin's corrosion inhibition behavior of carbon steel alloys immersed in 0.5 M HCl solutions. As increasing concentration, Kraft lignin and tannin became more effective inhibitors. Furthermore, Kraft lignin showed more effectiveness as a corrosion inhibitor than tannin.

Assessment of the corrosivity of AISI 1020 steel through microbiological analyzes and the mass loss technique in a clayey soil

This search aims to evaluate the corrosivity of AISI 1020 steel in clayey soil through microbiological analyzes and the mass loss technique. Through the results obtained, according to the identification methodology of the Bergey manual, the presence of two microorganisms was verified, Acidithiobacillus thiooxidans and ferrooxidans , responsible for the biocorrosion process , in addition to filamentous fungi. The presence of these bacteria does not generate a classification for the soil, however, it is known that they can accelerate the corrosion process when in contact with a metallic structure. Regarding the mass loss rate, a criterion used to simulate the assessment of corrosivity in pipes, NACE Standard RP-07-75 was adopted, which defined the intensity of the corrosive process, obtaining as a result for the sterilized sample a value considered low, since it was free of microbial activities and any other contaminating factor, but for the sample without sterilization, the soil was classified as having severe potential. Therefore, this research sought to correlate the characteristics of the soil representative of the Amazon with a process of corrosion of buried pipes due to the presence of microorganisms, which would correspond to a microbiological corrosion. Although, in many cases, there is suspicion of the accuracy of corrosion monitoring techniques, mass loss and microbiological identification techniques were used, which had a positive result in relation to the microbiological one.

Characterization of steel corrosion processes in various blended cements by means of coupled multi-electrode arrays

Supplementary cementitious materials can affect the porosity of concrete, pore solution pH and chloride binding, all of which influence the type and magnitude of corrosion damage. Advanced corrosion monitoring techniques are needed to follow the development of corrosion on steel embedded in concrete across space and over time. In this study, coupled multi-electrode arrays (CMEAs) were used to characterise corrosion processes in OPC and three blended cements. Cyclic wetting with chlorides was undertaken to initiate corrosion. The results showed three distinct types of corrosion: localised corrosion (CEM I), localised corrosion that expanded over time (CEM II), and a combination of localised and general corrosion (CEM III and CEM IV). Cathodic locations were also monitored successfully, and the corrosion behaviour was related to total porosity and pH of the pore solution. MicroCT was used to quantify the volume of corroded material, which agreed well with results calculated from the CMEA measurements.

Reliability Improvement of Magnetic Corrosion Monitor for Long-Term Applications.

Electromagnetic techniques are widely employed for corrosion detection, and their performance for inspection of corrosion is well established. However, limited work is carried out on the development and reliability of smart corrosion monitoring devices for tracking internal or buried thickness loss due to corrosion remotely. A novel smart magnetic corrosion transducer is developed for long-term monitoring of thickness loss due to corrosion at critical locations. The reliability of the transducer is enhanced by using a dissimilar active redundancy approach. The improved corrosion monitor has been tested in the ambient environment for seven months to evaluate the stability against environmental factors and degradation. The monitor is found to show great sensitivity to detect defects due to corrosion. Detection of anomalous patterns in the time series data received from the monitors is accomplished by using Pearson's correlation coefficient. The critical component of the monitor is identified at the end of the test. Research findings reveal that, compared to the existing corrosion monitoring techniques in the industry, the detection and isolation of faulty sensor features introduced in this study can contribute to reliable monitoring of thickness loss due to corrosion in ferromagnetic structures over an extended period of time.

Acoustic emission as a reliable technique for filiform corrosion monitoring on coated AA7075-T6: Tailored data processing

Acoustic emission (AE) was used for in-situ filiform corrosion (FFC) monitoring on coated AA77075-T6. The analysis of AE data using DBSCAN as clustering algorithm (validated by Bhattacharyya Coefficients´ evaluation) has revealed the presence of three clusters (out of four) related to phenomena involved in the FFC mechanism: metal-coating interface delamination due to opening (tensile), sliding (shear) and mixed mode enclosing both previous ones. The peak frequency was found to be the most relevant descriptor for clustering by using Random Forest classifier, and the correlation with the dominant frequencies range was validated obtaining the Power Spectrum Density of the AE signals.

Investigation of a few oxazolone molecules as corrosion inhibitor for API5LX60 steel in 1N H2SO4 solution

Corrosion is recognized as a notable problem in oil sector where API5LX60 steel transmission pipelines are in frequent use. In this report, three oxazolone derivatives as potential corrosion inhibitors were investigated on API5LX60 graded carbon steel in 1N H2SO4 solution in stagnant conditions at concentrations 50–200 ppm. Gravimetric weight loss coupons and electrical resistance corrosion monitoring techniques performed on test samples showed inhibitory properties with best at 200 ppm inhibitor concentration. The results further revealed that the degree of inhibition was concentration dependent. Inhibitor I exhibited the highest inhibition efficiency of 90.70% at 200 ppm concentration. Statistical analysis using multiple linear regression model procreated high R2 value of 0.998 and p-value < 0.0001 asserting a smooth linear dependence of inhibitor efficiency on oxazolone concentration and weight loss of the steel. Again, surface analysis affirmed the formation of protective coating of inhibitor on steel surface. Furthermore, the oxazolone inhibitor adsorbed physically on the steel surface and obeyed the Langmuir isotherm which is evident from the linear correlation coefficient value of 0.9992.

Corrosion monitoring techniques for concrete in corrosive environments

Abstract Replacing or servicing corroded reinforced concrete structures requires careful consideration of the rate of corrosion of the embedded rebar. Corrosion rates are usually measured using monitoring techniques, but these techniques may not always give reliable results due to the effect of factors called rate influencers. Though the consideration of rate influencers does not entirely alleviate the problem, monitoring them during measurements will significantly reduce the probable error. Hence, this paper compares the experimental results of prior studies with an effort to draw out the best corrosive environment for the efficient working of a few widely used monitoring techniques and presents a list of some major rate influencers that need concern for the accurate evaluation of corrosion. A literature review is performed to achieve the above objectives. The Monitoring techniques considered in this study are linear polarization resistance (LPR), electrochemical impedance spectroscopy (EIS), galvanostatic pulse technique (GPT), and half-cell potential (HCP).

Modified approximate entropy analysis for data processing of electrochemical noise with high time resolution toward corrosion monitoring

Electrochemical noise measurement (ENM) is a promising technique for online corrosion monitoring. However, developing suitable data processing methods of ENM recordings for describing corrosion systems with high time resolution remains a challenge. In this work, we introduced the modified approximate entropy (m-ApEn) algorithm to ENM data processing and successfully employed it in the analysis of magnesium corrosion in NaCl solution. This work not only provides a descriptor of m-ApEn to quantify the corrosion activity of the system, but also sheds light on novel data analysis methods of ENM with high time resolution toward corrosion monitoring.

An Instantaneous Corrosion Monitoring Technique based on Combining Modified Electrochemical Noise and Artificial Neural Network for Determination of Corrosion Type and 2014 Aluminium Alloy Corrosion Rate in NaCl and Ce(NO3)3 solutions

An Instantaneous Corrosion Monitoring Technique based on Combining Modified Electrochemical Noise and Artificial Neural Network for Determination of Corrosion Type and 2014 Aluminium Alloy Corrosion Rate in NaCl and Ce(NO3)3 solutions

Corrosion Monitoring in Atmospheric Conditions: A Review

A variety of techniques are available for monitoring metal corrosion in electrolytes. However, only some of them can be applied in the atmosphere, in which case a thin discontinuous electrolyte film forms on a surface. In this review, we describe, evaluate and compare both traditional and state-of-the-art real-time corrosion monitoring techniques to identify those suitable for atmospheric conditions. For atmospheric corrosion monitoring (ACM), electrochemical impedance spectroscopy (EIS), electrochemical noise (EN), electrical resistance (ER) probes, quartz crystal microbalance (QCM), radio-frequency identification sensors (RFID), fibre optic corrosion sensors (FOCS) and respirometry, the underlying principles, characteristics and application examples are described, and their advantages and drawbacks outlined. Finally, the techniques are compared in terms of their sensitivity, ease of setup, data processing, ability to identify underlying corrosion mechanisms and applicability in different fields of atmospheric corrosion protection and research.

Corrosion of Carbon Steel in Mauritian water bodies

Carbon steel is a commonly used metal in water applications in Mauritius. However, the corrosion resistance of steels and effectiveness of corrosion prevention methods in Mauritian water bodies are unknown. This study is performed to investigate the corrosion behavior of S235 carbon steel in the local tropical waters using various corrosion monitoring techniques. Specimens of the metal are subjected to a simple laboratory immersion test under ambient conditions according to ASTM G31. The coupons are immersed in three distinctively different waters. Upon removal after specific time intervals over a 3-month period, the mass loss, thickness loss and surface roughness are duly evaluated. Mass loss and thickness loss variation with time of immersion are obtained in the form of the power law function. Regarding the surface roughness parameters measured, it is observed that they change logarithmically with corrosion loss due to increasing thickness of the rust layer. A general deterministic model in terms of Rp and Rq is successfully stemmed using Genetic Programming to forecast the corrosion rate.

Spectral analysis for tilted fiber Bragg gratings in the corrosion detection for concrete structure

An effective corrosion monitoring technique is sought after by the engineers for assessing the steel bar corrosion at the early stage for the maintenance and repair works, especially in the corrosive environments, such as coastal and marine. In this work, tilted fiber Bragg grating (TFBG) with the optical sensor is employed in corrosion monitoring of a reinforced concrete structure. Taking advantage of the high sensitivity of TFBG cladding resonance wavelengths to the change in the surrounding medium, the sensor is mounted on the steel bar that is embedded in a concreted block during an accelerated corrosion process. The acquired transmission spectrum of the TFBG during the procedure is digitally processed using Fourier Transform to produce an index that is sensitive to the generated corrosion product surrounding the TFBG sensor. This eases the analysis of the sophisticated TFBG transmission spectra. The generated index can be used as an indicator (indicator J) for the corrosion process of the embedded steel bar in the concrete structure. This indicator J can act as an indicator to describe the corrosion activity and corrosion level at a specific point of the steel bar in concrete structures.

Insitu SVET studies on the current density distribution on dissolving of Mg, MgZn2, Mg2Si and Al4Cu2Mg8Si7 surfaces in NaCl solutions

PurposeThis paper aims to acquire the current density distribution on dissolving of Mg, MgZn2 (η -phase), Mg2Si (ß-phase) and Al4Cu2Mg8Si7 (Q-phase) surface in NaCl solutions.Design/methodology/approachMgZn2 (η -phase), Mg2Si (ß-phase) and Al4Cu2Mg8Si7 (Q-phase) are important intermetallic compounds found in aluminum alloys. Insitu scanning vibrating electrode technique (SVET) was used to acquire the current density distribution on dissolving of Mg, MgZn2 (η -phase), Mg2Si (ß-phase) and Al4Cu2Mg8Si7 (Q-phase) surface in NaCl solutions scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM/EDX) was used to characterize the corroded surface.FindingsSVET maps reveal that these compounds display characteristic dissolution features. Mg and MgZn2 displayed localized anodic and cathodic sites while that of Al4Cu2Mg8Si7 > Mg2Si displayed a diffused distribution of anodic and cathodic sites. The magnitude of the integrated anodic current densities on the compounds was noted to decrease with the progress of time, and the order of the magnitude of the current density with respect to the compounds is Mg > Mg2Si > Al4Cu2Mg8Si7 > MgZn2. SEM/EDX reveal that the highest mass loss recorded after the SVET test was manifested by Mg2Si followed by MgZn2 then Al4Cu2Mg8Si7.Originality/valueAuxiliary information on the current density distribution on the corroding sample surface at the microscopic scale has been provided by SVET thereby taking care of certain limitations of traditional corrosion monitoring techniques such as gravimetric, hydrogen evolution and electrochemical measurements.

Engineering molten MgCl2–KCl–NaCl salt for high-temperature thermal energy storage: Review on salt properties and corrosion control strategies

Conventional thermal energy storage (TES) media and heat transfer fluids (HTFs) currently used in commercial concentrated solar power (CSP) plants are nitrate-based molten salts with working temperature up to about 565 °C. Current interest in raising the working temperature in next-generation CSP for higher energy conversion efficiency leads to chloride-based molten salt technology (>700 °C). MgCl2–KCl–NaCl salt is selected to be such a TES/HTF material due to its excellent salt properties, abundance and low costs. In this review, survey and evaluation of its exact eutectic composition by evaluation of the phase diagram as well as most relevant salt properties for design, construction and operation of a test loop and projection of a real TES/HTF system are presented. They include minimum melting temperature, vapor pressure, heat capacity, density, thermal conductivity and dynamic viscosity. The working temperature range 420–800 °C is suggested for the TES/HTF system using this salt. Moreover, the recommended values of the heat capacity, density, thermal conductivity and dynamic viscosity in the suggested working temperature range are given. In addition, corrosion control strategies for this salt including corrosion monitoring and mitigation techniques are briefly reviewed, since controlling the salt corrosivity is one main concern of the engineering aspects using the molten chlorides at high temperatures. Overall, this review is expected to supply reliable values of the most relevant salt properties and recommend the most promising corrosion control strategies for further material studies, as well as modeling, simulation, detailed design and construction of molten MgCl2–KCl–NaCl salt TES/HTF systems.

Best practices for measurement, sensing, and quantifying corrosion in existing reinforced concrete structures

ABSTRACT Reinforced concrete structures are frequently exposed to environmental conditions in which active corrosion of embedded reinforcement occurs. Understanding the currently available techniques and methods, in combination with sound engineering judgment, are essential tools for detecting and measuring the rate of corrosion deterioration in reinforced concrete elements. This paper describes the current standard of practice for the evaluation, measurement, and monitoring of corrosion of steel in concrete structures and provides a ‘real-life’ perspective on the limitations and frequently encountered challenges in this endeavor. This manuscript is aimed at the concrete condition assessment practitioner and to academics studying the application and implementation of new corrosion monitoring and control techniques in practice.