Impressed current cathodic protection (ICCP) is an effective method for mitigating steel corrosion. Carbon fiber–reinforced polymer (CFRP) bars offer dual functionality in ICCP-integrated concrete structures, serving as both anodes and concrete reinforcement. This study investigates the behavior of CFRP bars subjected to anodic polarization in real concrete environments, rather than simplified solution-based conditions. Experimental evaluations were performed, including electrochemical monitoring to verify anodic performance, uniaxial tensile tests to assess residual mechanical properties, and microscopic characterizations to identify degradation mechanisms. Electrochemical measurements, including variations in feeding voltage and instant-off potential, confirmed the stability and reliability of CFRP bars as ICCP anodes. Tensile tests revealed a progressive reduction in residual strength with increasing current density and polarization duration, with negligible influence of concrete strength (30 and 60 MPa). Empirical models were developed to predict residual tensile strength, secant modulus, and ultimate strain based on electrochemical exposure parameters. As the current density or polarization time increased, the CFRP failure mode transitioned from longitudinal splitting fracture to lateral fracture, accompanied by a significant reduction in the fracture zone length. Acidification of the concrete adjacent to the CFRP–concrete interface was observed, with the concrete being powdery and porous. X-ray diffraction analyses revealed the depletion of alkaline hydration products and the formation of Friedel’s salt near the anode. Scanning electron microscopy showed resin dissolution, fiber–resin interface delamination, and cracking formation within the resin matrix. Fourier transform infrared spectroscopy confirmed hydrolysis and oxidative degradation of the resin, accelerated by exposure to OH− and Cl− and by moisture ingress, leading to progressive internal damage of the CFRP bar from the exterior inward.

Graphene is an ideal reinforcement for enhancing the corrosion resistance of low-zinc epoxy coatings owing to its high specific surface area, excellent conductivity, and barrier properties. However, the low electron transfer efficiency in such coating often leads to uniform corrosion of zinc powder with corrosion products enveloping its surface, causing premature failure and low zinc utilization. Herein, amino-functionalized graphene (Gr-NH2) was synthesized to prepare Gr-NH2 reinforced low-zinc epoxy coatings (Gr-NH2/ZEC, 40 wt % zinc), where edge-grafted -NH2 groups were covalently bonded to graphene and C-N-Zn electron pathways were established between graphene and zinc fillers. The enhanced Gr-NH2/Zn interfaces promote interfacial electron transfer, redirecting zinc corrosion from uniform corrosion to preferential intergranular corrosion, which continually fractures zinc particles and exposes fresh active surfaces. As a result, Gr-NH2/ZEC shows a high initial |Z|f=0.01 value of 1.16 × 108 Ω at 6 h immersion, which is approximately 5.4 times that of GO/ZEC. After 28 days of immersion corrosion, the |Z|f=0.01 value remained 8.88 × 107 Ω, which is very close to its initial value and still higher than that of GO/ZEC. Meanwhile, the enhanced intergranular corrosion also enables multiple reactivations of cathodic protection, thereby leading to a remarkable increase of zinc utilization efficiency from 9% to 20.5%. This interfacial engineering strategy provides a promising route for enhancing the cathodic protection performance of low-zinc epoxy coatings.

Corrosion and biofouling of metals in marine environments are critical issues affecting the long-term stability of marine engineering infrastructure. Traditional protection methods suffer from limitations such as high energy consumption and environmental pollution. Photoelectrochemical cathodic protection (PECCP) technology utilizes solar energy to drive the transfer of photogenerated electrons from semiconductors to metal surfaces, enabling green and low-energy-consumption corrosion protection. However, its core challenge lies in developing efficient and stable photoelectrode materials. In this study, a TiO2/CoNi-LDH composite photoanode was fabricated via hydrothermal and electrodeposition methods. It was found that under illumination, CoNi-LDH undergoes in situ reconstruction to generate CoOOH as a cocatalyst. The composite material exhibited excellent photoelectrochemical cathodic protection performance in a simulated seawater environment, providing a potential shift of 380 mV for coupled 304 stainless steel under intermittent illumination. Simultaneously, it demonstrated high antibacterial efficiency, achieving a 100% inactivation rate against Pseudomonas aeruginosa within 120 min. Structural characterization and theoretical calculations revealed that the in situ formation of CoOOH enhances interfacial charge transfer and promotes the generation of reactive oxygen species, thereby synergistically improving the anti-corrosion and anti-biofouling performance of the material. This study provides a novel strategy for developing integrated marine protective materials with long-term corrosion resistance and biofouling prevention capabilities.

When the strengthening material - fabric-reinforced cementitious matrix (FRCM) composite is used as the anode in the impressed current cathodic protection (ICCP) for reinforced concrete structures, its long-term performance will be compromised due to anode acidification. Incorporating graphene into the matrix offers a means of mitigating interface deterioration by delaying the localized calcium leaching. This paper presents the results of a study to investigate the mitigation effects of graphene on the mechanical and electrochemical properties of FRCM composites. Direct tensile and pull-out tests were performed on graphene-enhanced FRCM (Gr-FRCM) composites subjected to different ICCP current densities and graphene dosages. The results reveal that graphene significantly reduces the deterioration in tensile and interfacial properties induced by long-term ICCP. The degradation factor for the ultimate tensile strain of FRCM composites under ICCP follows an exponential relation of total electrons, whereas the addition of graphene reduces this factor by more than half. Two constitutive models were developed to predict the key mechanical parameter, the effective strain of fibres, in the FRCM composite subjected to cathodic protection with and without graphene. These models were validated against beam test results and shown to be accurate for calculations of the flexural resistance of concrete beams strengthened using Gr-FRCM composites.

This study investigates the hydrogen embrittlement susceptibility of laser melting deposition (LMD)-produced Ti-6Al-4V alloy with different build orientations (0°, 45°, 90°) through electrochemical hydrogen charging, slow strain rate testing, and microstructural characterization. Ti-6Al-4V alloys are widely used in marine and offshore engineering, where cathodic protection and corrosion reactions can generate hydrogen, leading to hydrogen ingress and potential embrittlement. Results show that prolonged hydrogen charging induces hydride formation, α-phase fragmentation, and β-phase dissolution, significantly degrading corrosion resistance and mechanical properties. Hydrogen embrittlement susceptibility exhibits notable anisotropy: elongation reductions for 0°, 45°, and 90° specimens are 40.1%, 40.8%, and 29.4%, respectively. The relatively superior resistance observed in the 90° orientation may be associated with its single-layer structure and more uniform dimple distribution. In contrast, the multilayer interfaces in other orientations are likely to serve as preferential sites for hydrogen accumulation, which may contribute to the increased embrittlement susceptibility. This research reveals the failure mechanism of LMD Ti-6Al-4V in hydrogen environments and supports its application in marine engineering.

Electro-osmotic control of X80 steel corrosion under HVDC interference

Electrochemical and stress corrosion behaviors of low-alloy high-strength steel in the soil environment of Western China

AI Transforms Cathodic Protection Workflows

In2S3-decorated TiO2 nanotubes with a Type-II heterojunction for enhanced photoelectrochemical cathodic protection of 316L stainless steel

Abstract The long-term integrity of buried ductile iron pipelines is increasingly compromised by external corrosion, especially where protective coatings are damaged or direct soil contact occurs. While coatings and cathodic protection remain essential for corrosion control, their long-term performance is strongly governed by the surrounding soil environment. In highly corrosive or moisture-retentive backfills, these conventional systems can degrade rapidly, leading to reduced protection efficiency and frequent maintenance. However, backfill design in current practice is primarily driven by mechanical considerations, such as providing adequate stiffness rather than corrosion resistance. To maximise the effectiveness of both structural support and corrosion protection, backfill properties should be understood from an integrated geotechnical and materials perspective; a connection that remains poorly understood. This review synthesises existing knowledge in both fields to demonstrate how key soil parameters such as moisture content, resistivity, pH, ion concentration, gradation, and compaction collectively influence the corrosion kinetics. Complementing the literature review, industry survey data from Australia provide insight into practical challenges and maintenance strategies. Findings highlight the need for performance-based backfill design to extend pipeline service life, reduce maintenance frequency, and support carbon-reduction goals in civil infrastructure.

Design of a dual-mode photoelectrochemical cathodic protection coating with an S-scheme heterojunction for steel in marine environments

The increasing deployment of offshore infrastructure has raised concerns about the environmental impact of corrosion protection systems, particularly galvanic anodes, which release trace metals such as zinc and aluminium into the marine environment. Traditional monitoring methods often fail to capture the bioavailable fraction of these contaminants or provide adequate temporal resolution. Here, we investigate the brown macroalga Saccharina latissima as a bioindicator of metal emissions from galvanic anodes. Laboratory and mesocosm experiments demonstrated linear relationships between environmental concentrations and metal accumulation, particularly for zinc. Compared to grab and passive sampling, S. latissima provided more consistent and representative exposure estimates. These findings highlight the potential of S. latissima as a cost-effective and reliable bioindicator for offshore trace metal contamination monitoring and its integration into environmental assessment frameworks.

Carbon dots (CDs) have demonstrated promising application prospects in the field of corrosion protection due to their small size, excellent dispersibility, abundant and tunable surface functional groups, low cost, environmental friendliness, and unique fluorescence properties. However, existing reviews have predominantly focused on the synthesis and photoluminescence properties of CDs, lacking systematic integration and in-depth mechanistic analysis of their diverse applications in corrosion protection. This review systematically summarizes the recent research progress and underlying mechanisms of CDs in five key areas: corrosion inhibitors, anticorrosive coatings, photogenerated cathodic protection, chloride binding, and corrosion monitoring. As corrosion inhibitors, CDs form compact protective films on metal surfaces through synergistic physical and chemical adsorption. In anticorrosive coatings, CDs not only enhance the physical barrier effect but also impart intelligent functionalities such as self-healing and corrosion monitoring. In the field of photogenerated cathodic protection, CDs broaden the light absorption range of semiconductors and facilitate the separation of photogenerated carriers. As chloride binding promoters, CDs promote the formation of cement hydration products, thereby improving the durability of reinforced concrete structures. As sensing platforms, CDs enable early visual detection of corrosion through their specific fluorescence response to ions such as Fe3+. Despite significant progress, challenges remain in scalable preparation, practical application performance in complex environments, and multifunctional integration. This review systematically outlines the research advancements of CDs in corrosion protection, providing a practical reference for subsequent studies and engineering applications. Future research should focus on scalable synthesis, machine learning-assisted design, and the development of integrated multifunctional protection systems to promote the practical application of CDs in the field of corrosion protection.

ABSTRACT Corrosion of metal materials in marine environments threatens the safety and durability of ships, offshore platforms, and coastal infrastructure. Conventional protection strategies often suffer from limited sustainability and poor adaptability under fluctuating marine conditions. Here, a hybrid power‐driven corrosion protection system (PTEG) integrating a photoanode, a triboelectric nanogenerator (TENG), and an electromagnetic generator (EMG) is developed to enable all‐weather cathodic protection. Under light illumination, the system generates a photocurrent density of 0.284 mA cm −2 , shifting the metal potential to − 0.845 V (vs. SCE). Under mechanical excitation alone, the synergistic TENG‐EMG unit delivers regulated DC output through an integrated power management circuit, achieving a protection potential of − 0.885 V (vs. SCE). Notably, only 93 s of wave energy input sustains effective protection for up to 5734 s. This work demonstrates a viable strategy for converting intermittent environmental energy into stable cathodic protection, offering a sustainable solution for corrosion mitigation in complex marine environments.

Zinc-rich coatings provide cathodic protection for metal substrates through the sacrificial anode action of zinc powder, which is widely used in marine equipment. However, zinc powder is easily covered by nonconductive corrosion products during service, resulting in low actual utilization rate of zinc powder and the failure of cathodic protection, which seriously restricts the long-term protective life of the coating. In this study, we designed a zinc-rich epoxy coating modified with 1-hydroxyethylidene-1,1-diphosphonic acid (HEDP), successfully builting an intelligent coating with a multilevel protection mechanism. The experimental results show that adding 2 wt·% HEDP (70Zn-HEDP) to a coating with a zinc powder content of 70 wt·% can increase the duration of its cathodic protection to twice that of the unmodified coating with a zinc powder content of 70 wt·% (70Zn), improve the utilization rate of zinc powder in the coating, and significantly slow down the zinc corrosion products, generate and enhance the physical blocking performance of the coating. With integrated electrochemical testing, morphological characterization, and DFT theoretical simulation, we reveal the multilevel protection mechanism of HEDP's multifunctionality: it preferentially chelates Zn2+ to sustain zinc reactivity and prolong cathodic protection, deposits insoluble complexes to seal coating defects. It ultimately generates a protective Zn/Fe-HEDP passivation layer upon exposure to steel. The multifunctional protection mechanism of organophosphates provides ideas for the design of the next generation of zinc-based anticorrosion coatings with both intelligent response and long service life.

A perceptible investigation of established educational institution buildings—specifically those aged 18 years and above—serves as a critical process for identifying necessary repair approaches and endorsing appropriate rehabilitation strategies. Over nearly two decades of continuous use, institutional structures often encounter material degradation, environmental wear, compliance gaps with updated safety codes, and evolving functional requirements. Perceptible investigation involves a combination of visual assessments, non-destructive testing (NDT), damage diagnostics, and structural health monitoring to evaluate the current condition of key building components, including concrete, steel reinforcements, partitions, and service infrastructures. Findings from these methods pinpoint both immediate hazards and latent deficiencies, such as cracks, spalling, moisture ingress, reinforcement corrosion, and compromised joints. Based on these investigations, targeted repair approaches are recommended—such as crack sealing, cathodic protection, fiber-reinforced polymer (FRP) strengthening, and surface repair. The integration of self-healing concrete, cathodic protection systems, and advanced crack injection techniques further enhances long-term serviceability and resilience of institutional buildings. Effective endorsement of repair methodologies is underpinned by a meticulous understanding of the extent of deterioration and tailored interventions that ensure structural integrity, safety, and operational continuity. Emphasis is placed on proactive maintenance and sustainable rehabilitation, securing the building's role as a safe and functional educational facility. These abstract highlights the necessity for systematic and perceptible investigation as a foundation for implementing innovative and durable repair techniques in aging educational institution buildings.

Evaluating the influence of silicon on phase formation, hardness and corrosion in Al–6.5% Mg alloy

Challenges and mitigations of corrosion and scale in nuclear cogeneration desalination systems: A case study from West Kalimantan

Microbiologically influenced corrosion dynamics and technological innovations in monitoring and control.

The article comprehensively examines the problem of ensuring the reliability of main oil pipelines in conditions of a changing soil environment, which significantly affects the intensity of corrosion processes. Particular attention is paid to the influence of soil moisture and ohmic resistance, which determine the electrochemical conditions for the formation of macrogalvanic couples – a key factor accelerating localized corrosion of pipeline metal. The aim of the study is to create a mathematical model capable of accurately describing the distribution of electrochemical potentials and corrosion currents along the pipeline system, taking into account both the properties of the metal and the variable parameters of the external environment. The proposed numerical model is based on solving a system of nonlinear algebraic equations using iterative methods, which allows for detailed simulation of the effect of variable soil moisture on the electrochemical behavior of metal surfaces. The article also provides an analytical description of changes in the parameters of a macrogalvanic couple depending on the level of moisture and electrical resistance of the soil, and proposes a method for calculating the specific polarizability of pipeline metal in different sections of the pipeline. The proposed model allows not only to accurately assess the remaining resource of pipeline systems, but also to identify accident-prone areas in a timely manner, thereby increasing the efficiency of cathodic protection systems. The results obtained are of practical value for the creation of specialized engineering software and can be used in the development of the latest regulatory and technical documents in the field of monitoring and protection of underground pipeline systems. Keywords: steel oil pipeline, electrochemical corrosion, longitudinal galvanocouple, corrosion model, corrosion rate, environmental safety.