Corrosion Sensor Research Articles

Distributed Embedded System for Multiparametric Assessment of Infrastructure Durability Using Electrochemical Techniques.

We present an autonomous system that remotely monitors the state of reinforced concrete structures. This system performs real-time follow-up of the corrosion rate of rebars (iCORR), along with other relevant parameters such as temperature, corrosion potential (ECORR), and electrical resistance of concrete (RE), at many of a structure's control points by using embedded sensors. iCORR is obtained by applying a novel low-stress electrochemical polarization technique to corrosion sensors. The custom electronic system manages the sensor network, consisting of a measurement board per control point connected to a central single-board computer in charge of processing measurement data and uploading results to a server via 4G connection. In this work, we report the results obtained after implementing the sensor system into a reinforced concrete wall, where two well-differentiated representative areas were monitored. The obtained corrosion parameters showed consistent values. Similar conclusions are obtained with ECORR recorded in rebars. With the iCORR follow-up, the corrosion penetration damage diagram is built. This diagram is particularly useful for identifying critical events during the corrosion propagation period and to be able to estimate structures' service life. Hence, the system is presented as a useful tool for the structural maintenance and service life predictions of new structures.

Corrosion monitoring for transmission line based on electromechanical impedance instrumented circular piezoelectric corrosion sensor

Corrosion-induced thickness loss is a common form structural damage in transmission lines. In our previous work, a novel circular piezoelectric-metal transducer for corrosion sensing using the electromechanical impedance (EMI) technique was proposed. This transducer was fabricated by attaching a lead zirconate titanate (PZT) patch to a metal plate. In the present study, the piezoelectric-metal transducer was encapsulated and enhanced, and two types of corrosion sensors were developed: piezoelectric-steel and piezoelectric-zinc sensors. To assess the practical performance of the corrosion sensors, the piezoelectric-steel and piezoelectric-zinc sensors were connected to the angle steels and the steel strands, which are highly prone to corrosion in transmission lines. Corrosion monitoring experiments were conducted in the laboratory. The results demonstrate that the peak frequencies in the conductance signatures decrease linearly with increasing corrosion-induced thickness loss. Furthermore, it was found that piezoelectric-steel sensors are effective for quantitative monitoring of metallic corrosion, whereas piezoelectric-zinc sensors are better suited for early-stage corrosion monitoring and warning.

Examination of Impaction Efficiency of Sea-Salt Particle for an Airborne Sea-Salt and a Corrosion Sensor Using CFD Model

Examination of Impaction Efficiency of Sea-Salt Particle for an Airborne Sea-Salt and a Corrosion Sensor Using CFD Model

A novel electroless nickel plating process for fabrication of optical fiber corrosion sensors

In this work, a novel silanization pre-treatment method has been successfully proposed to solve the problems of discontinuity and poor adhesion strength of electroless nickel plating using in the ultrasensitive optical fiber corrosion sensors. The chemically etched and hydroxylated optical fiber is simply treated with a mixed solution containing the hydrolyzed γ-APS with bifunctional group and PdCl2 before dipping into nickel plating solution. ATR-FTIR, AFM, SEM and theoretical calculations are applied to demonstrate the feasibility of the method and reaction mechanism. Results show that the –NH2 in γ-APS preferentially interacts with the Pd2+, while the Si-OH at the other end forms a covalent bond with the Si-OH on the optical fiber surface, forming a needle-like silane intercalation film by oriented adsorption. With this simple silanization pre-treatment method, a uniform and continuous electroless nickel plating can be successfully prepared. Our DFT calculations are good consistent with the experimental measurements.

Research and development of corrosion monitoring sensor for bridge cable using electrical resistance probes technique

A cable corrosion monitoring sensor with a temperature compensation probe has been designed and manufactured to monitor the corrosion of high-strength steel wires in the transition zone between the cable body and the anchorage. The influence of temperature and tensile force on the resistance of steel wires was thoroughly investigated. Reliability tests were conducted on the temperature compensation probe, along with salt spray corrosion tests on the corrosion sensor. The research results demonstrated that, compared to the temperature sensor, temperature compensation probe can better reflect the actual temperature of the corrosion sensor and provide effective temperature compensation for the corrosion sensor. Moreover, the developed corrosion sensor can effectively reflect the mass loss rate of the corrosion probe. The sensor is capable of detecting a corrosion level as low as 0.02 % of the complete steel wire mass, which corresponds to an average corrosion depth of 0.412 μm.

Accelerated corrosion of low carbon steel by oscillatory acidic streams generated with a bio-inspired claw device.

A mechanical device inspired by the pistol shrimp snapper claw was developed. This technology features a claw characterized by a periodic opening/closing motion, at a controlled frequency, capable of producing oscillating flows at transitional Reynolds numbers. An innovative method was also proposed for determining the corrosion rate of carbon steel samples under oscillating acidic streams (aqueous solution of HCl). By employing very-thin carbon steel specimens (25 μm thickness), with one side coated with Zn and not exposed to the stream, it became possible to electrochemically sense the Zn surface once the steel sample was perforated, thus providing the average dissolution rate into the most relevant pit on the steel surface. Furthermore, a laser light positioned beneath the metallic sample, along with a camera programmed to periodically capture images of the steel surface, facilitated the accurate counting of the number of newly formed pits. The system consisting of the thin steel sample and the Zn coating can be seen as a type of corrosion sensor. Furthermore, the proposed laser illumination method allows corroborating the electrochemical detection of pits and also establishing their location. The techniques crafted in this study pave the way for developing alternative corrosion sensors that boast appealing attributes: affordability, compactness, and acceptable accuracy to detect in time and space localized damage.

In situ detection of spatial distribution information of temperature-pH-strain of sandstone cultural relics

To monitor in situ the temperature, pH, and micro-strain change information of sandstone artifacts in the process of oxalic acid corrosion, the temperature, pH, and micro-strain fiber Bragg grating (FBG) sensors are developed. A theoretical model of the sensors is established. The surface morphology, material composition, pore structure, temperature, pH, and micro-strain of sandstone corroded by oxalic acid solutions of different concentrations are investigated. The experimental results show that the higher the concentration of oxalic acid, the stronger the corrosiveness of the sandstone. Ferrous oxalate and calcium oxalate produced by corrosion continuously precipitate from the inside of the rock, and the dual reaction of crystallization and dissolution occurs, reducing the proportion of fine pores in the rock pore suction and gravity. The oxalic acid solution is transported to the middle of the sandstone (3 cm) and undergoes the strongest chemical reaction with ore particles and debris, resulting in the maximum wavelength drift of the temperature, pH, and micro-strain sensors. The results of this study provide important support for analyzing the acid dissolution mechanism of stone cultural relics and the preventive protection of cultural relics.

Probability of detection for corrosion-induced steel mass loss using Fe–C coated LPFG sensors

The traditional probability of detection (POD) method, as described in the Department of Defense Handbook MIL-HDBK-1823A for nondestructive evaluation systems, does not take the time dependency of data collection into account. When applied to in situ sensors for the measurement of flaw sizes, such as fatigue-induced crack length and corrosion-induced mass loss, the validity and reliability of the traditional method is unknown. In this paper, the POD for in situ sensors and their associated reliability assessment for detectable flaw sizes are evaluated using a size-of-damage-at-detection (SODAD) method and a random parameter model (RPM). Although applicable to other sensors, this study is focused on long-period fiber gratings (LPFG) corrosion sensors with thin Fe–C coating. The SODAD method uses corrosion-induced mass losses when successfully detected from different sensors for the first time, while the RPM model considers the randomness and difference between mass loss datasets from different sensors. The Fe–C coated LPFG sensors were tested in 3.5 wt.% NaCl solution until the wavelength of transmission spectra did not change. The wavelength shift of 70% of the tested sensors ranged from 6 to 10 nm. Given a detection threshold of 2 nm in wavelength, the mass losses at 90% POD are 31.87%, 37.57%, and 34.00%, which are relatively consistent, and the upper-bound mass losses at 95% confidence level are 33.20%, 47.30%, and 40.83% from the traditional, SODAD, and RPM methods, respectively. In comparison with the SODAD method, the RPM method is more robust to any departure from model assumptions since significantly more data are used. For the 90% POD at 95% confidence level, the traditional method underestimated the mass loss by approximately 19%, which is unconservative in engineering applications.

Extraction of atmospheric corrosion monitoring sensor signals using MSSA and corrosion progress prediction with an LSTM model

The sensitivity of corrosion signals to temperature fluctuations often presents significant challenges for signals acquired from corrosion sensors. The main objective of this study is to assess these signals collected by the atmospheric corrosion monitoring sensor based on strain measurement through the application of multivariate singular spectrum analysis (MSSA) for extracting corrosion signal data. The study results demonstrate that MSSA has consistently exhibited exceptional performance in isolating corrosion signals, particularly in scenarios where they are affected by inherent noise resulting from abrupt temperature changes, corrosion products and residual stress. Moreover, the corrosion signals extracted via MSSA were harnessed to create a long short-term memory (LSTM) model, with the aim of predicting future corrosion processes. The results of this study emphasize the effectiveness and reliability of the LSTM model in forecasting corrosion processes. This study holds a crucial role in the management of corrosion processes in materials exposed to atmospheric conditions, ensuring both structural integrity and industrial safety.

Selective flexible sensor for monitoring volatile organic compounds in museum display cases

Aim of this work is the development of a new kind of corrosion sensors, based on low-cost flexible substrates, specifically designed to detect Volatile Organic Compounds (VOCs) producing significant degradation of artifacts in museum display cases. Sensors have been fabricated and tested in relevant environment with three of the most relevant VOCs (acetic acid, formic acid and formaldehyde) to the artifacts preservation. Sensitivity has been measured to be lower than 1 ppm, which is several times better than what reported in the literature on corrosion sensors for the same VOCs. In addition, different sensors, arranged with different active materials, have been implemented for the first time into a so-called multi-sensor architecture, aimed at demonstrating VOC specificity: in particular, we report here on a preliminary test in which the multi-sensor has been able to be selective between acetic acid and formaldehyde.

Case study: use of SHM to support bridge assessment, maintenance and operation

AbstractThe assessment of infrastructure conditions is at present a topic of great interest and importance, as well as great challenge. This paper presents a case study of the Samuel De Champlain Bridge (Montreal, QB, Canada), an outstanding stay cable bridge equipped with a comprehensive monitoring system (SHM). Among other SHM features, particular attention was paid to implementation of a strategic corrosion monitoring system. This paper intends to describe the concept design, implementation and data interpretation. Here corrosion sensors have been embedded during construction stage to monitor long term evolution of key electro‐chemical parameters for controlling deterioration of materials. Furthermore, these sensors measure stray current interference generated from the rail system that can cause corrosion. In both cases, abnormal values would warn the owner of the associated increased risk of corrosion. This gives them the possibility to take corrective measures to protect the structure before corrosion becomes a serious threat.

Optimization for Pipeline Corrosion Sensor Placement in Oil-Water Two-Phase Flow Using CFD Simulations and Genetic Algorithm.

Internal corrosion is a major concern in ensuring the safety of transmission and gathering pipelines in Structural Health Monitoring (SHM). It usually requires numerous sensors deployed inside the piping system to comprehensively cover the locations with high corrosion rates. This study presents a hybrid modeling strategy using Computational Fluid Dynamics (CFD) and Genetic Algorithm (GA) to improve the sensor placement scheme for corrosion detection and monitoring. The essence of the proposed strategy harnesses the well-validated physical modeling capability of the CFD to simulate the oil-water two-phase flow and the stochastic searching ability of the GA to explore better solutions on a global level. The CFD-based corrosion rate prediction was validated through experimental results and further used to form the initial population for GA optimization. Importantly, fitness was defined by considering both sensing effectiveness and cost of sensor coverage. The hybrid modeling strategy was implemented through case studies, where three typical pipe fittings were used to demonstrate the applicability of the sensor layout design for corrosion detection in pipelines. The GA optimization results show high accuracy for sensor placement inside the pipelines. The best fitness of the U-shaped, upward-inclined, and downward-inclined pipes were 0.9415, 0.9064, and 0.9183, respectively. Upon this, the hybrid modeling strategy can provide a promising tool for the pipeline industry to design the practical placement.

Potential influence of microorganisms on the corrosion of carbon steel in the French high‐level long‐lived radioactive waste disposal context at 80°C

AbstractIn this study, experiments were carried out to assess the microbially influenced corrosion (MIC) risk in the context of the French high‐level radioactive waste disposal. The exposures were carried out at 80°C in different repository relevant conditions, including the presence of different cement‐grout mixtures as filling material. Biotic conditions with nutrient and nonsterile conditions with indigenous microbes added from Callovo Oxfordian clayey rock and without nutrients were considered. For biotic conditions, specific preparations of microbial inoculum were carried out from samples collected at Andra's Underground Research Laboratory and microorganisms from microbial culture collection centers. Corrosion kinetics were determined using traditional coupons and completed with real‐time corrosion sensors. Microbiological characterizations consisted of cultural approach, quantitative polymerase chain reaction, and next‐generation sequencing. The obtained results show no significant MIC and a reduced risk with the use of more alkaline filling material.

High-Order Fiber Bragg Grating Corrosion Sensor Based on the Detection of a Local Surface Expansion

This paper presents a fiber optic sensor for the detection of corrosion processes that occur on metal surfaces. In the proposed sensor design, a sensing fiber with an inscribed high-order Bragg grating is attached to the observed metal surface. A broadening of high-order Bragg grating spectral characteristics is observed and used to detect small and highly localized longitudinal strain variations that occur along the fiber as a result of corrosive rust flakes’ formations beneath the sensing fiber. The proposed approach provides a straightforward fabrication method, the possibility for unobtrusive mounting, including mounting of the sensor beneath the corrosion-protective layers, and consistent corrosion detection yields.

Study on the influence law and mechanism of industrial atmospheric environment on the corrosion behavior of Q235 carbon steel

This paper combines the traditional hanging test and corrosion sensor technology to study and explore the corrosion law and its mechanism of Q235 carbon steel in industrial atmospheric environment. The results show that Hangzhou’s industrial atmospheric corrosion is a constantly changing and highly variable corrosion intensity process with the corrosive strength shows a seasonal trend. Through the analysis of weight loss, macroscopic corrosion morphology, microscopic corrosion morphology and elemental distribution, it showed that the traditional hanging test results and sensor test results had a good correspondence, indicating that the sensor values can be used to study the corrosion of the outdoor samples.

Corrosion sensor based on surface plasmon resonance effect of core-offset splicing fiber

A corrosion monitoring sensor is proposed based on the surface plasmon resonance (SPR) effect of core-offset splicing fiber. Using the arc fusion splicing method, this sensor is fabricated by cascading together a single-mode fiber (SMF), a graded-index multimode fiber (GI-MMF), and a step-index multimode fiber (SI-MMF). The SMF and GI-MMF are core offset spliced to enhance evanescent field by coupling the transmission light into the cladding. The outer layer of GI-MMF is coated with 50 nm silver film, which can effectively excite the SPR effect and detect corrosion. The sensor has good reproducibility, and shows a high sensitivity for early corrosion in atmospheric weak acid pollutants, which can be applied to early metal corrosion monitoring and weak acid atmospheric corrosion evaluation.

The Deutsches Museum Spacesuit Display: Long-Term Preservation and Atmospheric Monitoring

Spacesuits are highly valuable artifacts made of sensitive synthetic materials, including rubber, polyvinylchloride, polyamide, or polyurethane. The main concerns for preservation are off-gazing from the objects themselves and the exterior agents of deterioration humidity, high temperature, UV radiation, and visible light. This study addresses the implementation of preventive conservation in the Deutsches Museum spacesuit display and the evaluation of the atmosphere with monitoring methods. The focus lies on innovative RFID corrosion sensors developed by the Lab-STICC and used in an exhibition for the first time. In addition, commercial devices (climate logger, UV and light meters, infrared thermal imaging) were used to check the conditions in the spacesuit showcase. The source for off-gazing coming from a suit could be located through the sensors, and the low corrosivity inside the showcase showed the effectivity of the installed charcoal absorbers. Humidity, however, was unable to be reduced to the recommended 30–40% in the large-scale showcase with silica gel. The LED lighting in the dark exhibition excludes any harmful high-energy radiation, but thermal radiation is produced by lighting and electrical devices. The applied methods were effective in evaluating the current situation in the exhibition and form a good basis for future improvements on the display.

Automatic detection of steel rebar corrosion based on machine learning and light spectrum of fiber optic corrosion sensors

A method for automatic monitoring of steel rebar corrosion by integrating machine learning (ML) with single mode-multimode-single mode (SMS) fiber optic corrosion sensors is proposed in this study. SMS fiber optic corrosion sensors are fabricated in the laboratory and employed for corrosion monitoring of steel rebar in 3.5 wt% NaCl solution. The data of both the transmission spectrum of the SMS fiber optic corrosion sensor and the corrosion-induced mass loss of steel rebar are collected for training ML models. A total of twelve ML algorithms is trained and compared based on the whole and portion of the light spectrum database. Results show that only seven ML algorithms demonstrate good performance based on the whole original transmission spectrum data obtained from the SMS fiber optic corrosion sensors. However, they show poor performance based on portion of the database in corroded chronological order in comparison with those based on the whole database due to the nonlinear relationship between the corrosion-induced mass loss of steel rebar and the shift of the transmission spectrum of the SMS fiber optic corrosion sensors. The limitations of the ML algorithm based on laboratory data in this study are discussed and future work regarding real structure applications are also anticipated.

Design of corrosion sensors by using 1D quaternary photonic crystal with defect layer

Design of corrosion sensors by using 1D quaternary photonic crystal with defect layer

Experimental research of electrical characteristics combined solar-electric air heater

Poor water quality in district heating systems leads to failure of boilers and pipelines in heating networks. The main reason for this is corrosion and scale deposits. The presence of these factors shows the low efficiency of water treatment systems. The article presents the results of the introduction of non-traditional water treatment technologies for district heating systems based on the experience of the Zhytomyrteplokommunenergo utility company of the Zhytomyr City Council in 2007-2021. In the boiler houses of the enterprise, water treatment systems were modernized, and the production chemical service was reorganized. In particular, chemical deaeration was launched in combination with traditional sodium cationization, as well as chemical deaeration in combination with complexonate water treatment against the classical water treatment technology - ion exchange. Installed magnetic sludge separators with magnetic inserts. The technology of water softening with anti-corrosion protection using Redox filters has been introduced. Gravimetric corrosion sensors of our own design have been developed and installed. The database of processing and statistical analysis Access "Corrosion damage of pipelines of heat networks" was created and put into operation. The experience of modernizing the water treatment system has shown that work in this direction increases the reliability of operation of district heating systems by reducing the consumption of energy carriers and material resources. In addition, the problem of improving the operational reliability of the heat exchange equipment of thermal stations needs to be solved. The projected start of the use of heat recovery devices on water heating boilers in operation, in condensation or partially condensation modes, will also bring with it a number of problems with the neutralization of condensate and its return to the heat supply system. The end result is an increase in production reliability, environmental friendliness and a reduction in the cost of heat for district heating systems.