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Marine corrosion is a kind of material failure phenomenon caused by the interaction between metal structure and marine environment. As an efficient and simple anti-corrosion method, gaseous corrosion inhibitor can have a good inhibition effect on marine atmospheric corrosion. How to effectively use the compound environment-friendly vapor phase corrosion inhibitor has been widely and efficiently applied in the field of marine atmospheric corrosion, which has become the key to prevent marine atmospheric corrosion. In this paper, we introduce the development history, inhibition mechanism, classification, compounding and structure-activity correlation of vapor phase corrosion inhibitors, and the research prospect of environment-friendly vapor phase corrosion inhibitors in marine environment is prospected.

In this study, we optimized the traditional composition of AISI 8630 steel and evaluated its corrosion resistance through a series of tests. We conducted corrosion tests in a 3.5% NaCl solution and performed a 720 h fixed-load tensile test in accordance with the NACE TM-0177-2016 standard to assess sulfide stress corrosion cracking (SSCC). To analyze the corrosion products and the structure of the corrosion film, we employed X-ray diffraction and transmission electron microscopy. The corrosion rate, characteristics of the corrosion products, structure of the corrosion film, and corrosion resistance mechanism of the material were investigated. The results indicate that the optimized AISI 8630 material demonstrates excellent corrosion resistance. After 720 h of exposure, the primary corrosion products were identified as chromium oxide, copper sulfide, iron oxide, and iron–nickel sulfide. The corrosion film exhibited a three-layer structure: the innermost layer with a thickness of 200–300 nm contained higher concentrations of alloying elements and formed a dense, cohesive rust layer that hindered the diffusion of oxygen and chloride ions, thus enhancing corrosion resistance. The middle layer was thicker and less rich in alloying elements, while the outer layer, approximately 300–400 nm thick, was relatively loose.

Fe-Mn-Al-C lightweight steel is an alternative to traditional low-alloy structural steels. It is lightweight and can be used to reduce the weight of structures without increasing their density. However, in the marine environment, traditional low-alloy structural steels can be damaged by chloride ions, which shortens their service life. We do not yet understand how aluminum, an important alloying element in lightweight steel, affects the process of corrosion. In this study, we examined Fe-Mn-Al-C lightweight steels with different amounts of aluminum. We used full-immersion simulated marine corrosion tests and multi-dimensional characterization techniques, such as microstructure observation and electrochemical measurements, to explore the relationship between aluminum content and the steel’s corrosion rate, corrosion product structure, and corrosion resistance. The results showed that, compared with CS, the weight loss and rate of corrosion of steels that contain aluminum were a lot lower. While the corrosion rate of CS is approximately 0.068 g·h−1·m−2, that of 7Al steel is reduced to 0.050 g·h−1·m−2. The stable phases α-FeOOH and FeAl2O4 are formed in the corrosion products when Al is added. As the Al content increases, so does the relative content of these phases. Furthermore, FeAl2O4 acts as a nucleation site that refines corrosion product grains, reduces pores and cracks, and significantly improves the compactness of corrosion products. It also forms a dense inner rust layer that blocks the penetration of corrosive ions such as Cl−. This study confirmed that aluminum improves the corrosion resistance of steel synergistically by regulating the structure of the corrosion products, optimizing the phase composition, and improving the electrochemical properties. The optimal aluminum content for lightweight steel in marine environments is 7%, within a range of 5–9%.

Protection against microbiologically influenced corrosion (MIC) is critical for materials used in aquatic environments, as MIC accelerates material degradation and leads to faster structural failure. Copper (Cu) has the potential to substantially improve the MIC resistance in alloys. In this study, high-entropy alloy (HEA) coatings containing Cu were deposited using DC (Direct Current) magnetron sputtering to enhance the corrosion resistance and mechanical properties of various substrates. Two CuCrFeMnNi HEA compositions in the form of bulk alloys and PVD (Physical Vapor Deposition) coatings, with 5% and 10% Cu, were analyzed for their microstructural, mechanical, and anticorrosive characteristics. Deposition parameters were varied to select the optimal values. Microstructural evaluations using SEM-EDS (scanning electron microscopy and energy dispersive X-ray spectroscopy), XRD (X-ray diffraction), and AFM (atomic force microscopy) revealed uniform, dense coatings with good adhesion composed of dendritic and interdendritic BCC (body-centered cubic) and FCC (face centered cubic) structures, respectively. Microhardness tests indicated improved mechanical properties for the samples coated with developed HEAs. The coatings exhibited improved corrosion resistance in NaCl solution, the 10% Cu composition displaying the highest polarization resistance and lowest corrosion rate. These findings suggest that Cu-containing HEA coatings are promising candidates for applications requiring enhanced corrosion protection.

Hydrogen permeation into high-strength steel during the corrosion process can deteriorate their mechanical properties, thus seriously threatening the safety of steel structures. However, the hydrogen permeation behavior of steels in corrosive marine environments is not well understood. In this study, the hydrogen permeation behavior and mechanism of AISI 4135 steel in different marine corrosion zones was investigated for the first time using an in situ hydrogen permeation monitoring system via outdoor and indoor tests. The three-month outdoor hydrogen permeation test showed that the diffusible hydrogen content of the steels exposed to the marine atmospheric, splash, tidal and immersion zone was 3.15 × 10−3, 7.00 × 10−2, 2.06 × 10−2 and 3.33 × 10−2 wt ppm, respectively. Meanwhile, results showed that the hydrogen permeation current density was positively correlated with the corrosion rate of the steel in the marine environments. This research is of great significance for guiding the safe application of high-strength steel in the marine environments.

Corrosion is the predominant failure mechanism in marine steel, and accurate corrosion prediction is essential for effective maintenance and protection strategies. However, the limited availability of corrosion datasets poses significant challenges to the accuracy and generalization of prediction models. This study introduces a novel integrated model designed for predicting marine corrosion under small sample sizes. The model utilizes dynamic marine environmental factors and material properties as inputs, with the corrosion rate as the output. Initially, a genetic algorithm (GA)-optimized machine learning framework is employed to derive the optimal GA-XGBoost model. To further enhance model performance, a virtual sample generation method combining Gaussian Mixture Model and Regression Generative Adversarial Network (GMM-RegGAN) is proposed. By incorporating these generated virtual samples into the base model, the prediction accuracy is further improved. The proposed framework is validated using corrosion datasets from six types of marine steel. Results demonstrate that GA optimization substantially improves both the performance and stability of the model. Virtual sample generation further enhances predictive performance, with reductions of 14.94% in RMSE, 15.55% in MAE, and 14.04% in MAPE. The results indicate that the proposed method offers a robust and effective framework for corrosion prediction in scenarios with limited sample data.

Marine is the harshest corrosive environment where almost all marine underwater equipment and facilities undergo corrosion caused by marine microorganisms. With the development of marine resources globally, the marine engineering and relevant infrastructures have increased exponentially. Microbiologically influenced corrosion (MIC) leads to severe safety accidents and great economic losses. The specific aggregation of corrosive microbial communities and their interactions with materials conform to a typical ecological adaptation mechanism. On the one hand, corrosive biofilms in the marine environment selectively colonize on a specific steel substrate by utilizing their complex community composition and various extracellular polymeric substances; on the other hand, the elemental composition and surface microstructure of different engineering steels affect the microbial community and corrosive process. MIC in the marine environment is a dynamic process evolving with the formation of corrosive biofilms and corrosion products. In this mini-review, the interactions between corrosive biofilm and steel substrates are explored and discussed, especially those conducted in situ in the marine environment. Herein, the important role of iron in the dynamic process of marine corrosion is highlighted.

With the rapid development of marine engineering, effective antifouling and anti-corrosion technologies are essential for ensuring the safety and longevity of marine facilities. This review synthesizes current research on various coating technologies designed to combat marine biological fouling and corrosion. It analyzes the causes of marine biological fouling and corrosion, discusses their potential impacts on the safety of ships and marine structures, and emphasizes the need for effective protective systems. The review covers current antifouling coating technologies, including the preparation of low-surface-energy coatings, conductive coatings, biomimetic coatings, polysiloxane coatings, polyurea coatings, epoxy coatings, polyurethane coatings, and high-entropy alloy coatings. Anti-corrosion coatings are also discussed, with a focus on the characteristics of epoxy, polyurethane, and polyurea coatings, as well as metal-based coatings, alongside their corrosion resistance in marine environments. Based on existing research, the review summarizes ongoing challenges in marine antifouling and anti-corrosion coating technologies, and offers perspectives on future research directions and technological developments.

Microbially influenced corrosion (MIC) is a formidable challenge in the marine industry, resulting from intricate interactions among various biochemical reactions and microbial species. Many preventions used to mitigate biocorrosion fail due to ignorance of the MIC mechanisms. This review provides a summary of the current research on microbial corrosion in marine environments, including corrosive microbes and biocorrosion mechanisms. We also summarized current strategies for inhibiting MIC and proposed future research directions for MIC mechanisms and prevention. This review aims to comprehensively understand marine microbial corrosion and contribute to novel strategy developments for biocorrosion control in marine environments.

This research aims to evaluate the effectiveness of protective coatings in preventing the corrosion of steel in the marine environment. Electrochemical tests were performed on S355JR steel immersed in natural seawater (Black Sea, Port Constanta) over a period of 22 weeks, using electrochemical techniques such as the evolution of the open circuit potential (OCP) and linear polarization resistance to calculate Rp and the corrosion rate (Vcorr). The investigated steel surfaces included (a) S355JR steel blasted with Al2O3, (b) S355JR steel blasted and coated with epoxy primer enriched with zinc, (c) S355JR steel blasted and coated with epoxy primer and polyurethane paint, and (d) S355JR steel blasted and subsequently coated with epoxy primer and then polyurethane paint to which kreutzonit particles had been added. The proportion of kreutzonit particles added to the polyurethane paint was 2 wt% of the total mass of the paint. Subsequently, the samples were subjected to morphological analyses and cross-sectional analysis by scanning electron microscopy (SEM), topographical characterization (roughness and microhardness), and structural assessments (FTIR and XRD), as well as an analysis of hydrophobicity (contact angle). The results of this study revealed significant differences in corrosion behavior between the different surfaces and coatings tested. Electrochemical analysis revealed that the coating with epoxy primer and polyurethane paint to which kreutzonit particles had been added provided the best corrosion protection in the marine environment during immersion.