Mg-alloy have the advantages of low density and high specific strength, which are as green metal structural materials in the 21st century and show great potential in the application in marine environment. However, the poor corrosion resistance and unique marine environment limit their application. In this work, the corrosion behavior and corrosion mechanism of Mg-alloy in marine atmospheric environment, seawater immersion environment and coastal beach environment are reviewed. The effect of humidity, temperature and pollutants on the corrosion behavior of Mg-alloy in atmospheric environment and the effect of Cl^- on their corrosion behavior in seawater environment are analyzed. The corrosion mechanism of magnesium anode in seawater battery was introduced. The effect of microbial corrosion on metal corrosion behavior in beach environment is also briefly introduced. According to the application of Mg-alloy in marine environment, how to improve the corrosion resistance and service life of Mg-alloys is briefly introduced. Generally, there are two main methods to improve the corrosion resistance of Mg-alloys in marine atmospheric environment: one is to improve the corrosion resistance of Mg-alloy by alloying with other metal elements and changing the processing technology to alter the microstructure of Mg-alloys; the other is to form a chemical protective film on the surface of the Mg-alloys. Besides, Mg-alloys are mainly used as anode materials for seawater batteries in seawater environment, correspondingly, their electrochemical properties can be improved by adding other metal elements to Mg-alloys. Mg-alloy can be used as sacrificial anode material for pipelines in tidal flat environment, for that circumstance, mainly by adding metal elements to improve its cathodic protection efficiency. However, there are few studies on improving the protection efficiency of Mg-sacrificial anode in tidal flat environment, which needs further research in the future. This paper aims to provide a reference for the application and protection of Mg-alloys in the marine environment.

As a secondary battery, aqueous zinc-ion battery has advantages of good safety, low cost and high energy density, and is expected to become a substitute candidate for the next generation of energy storage systems. As a promising energy storage device, aqueous zinc-ion batteries have made major breakthroughs in many research fields. However, the corrosion of zinc metal anode is still a key factor hindering its development, which seriously weakens the stability and service life of zinc-ion batteries in practical applications. Therefore, it is of great application value to study how to prevent the corrosion of zinc metal anode. In this paper, the corrosion protection strategies and research progress for zinc metal anode and electrolyte in aqueous zinc-ion batteries are systematically summarized, and the further application prospect is prospected.

The safe disposal of high-level radioactive waste is an international challenge. Deep geological disposal repository for high-level radioactive waste with multibarrier system design concept is being planned to construct in China to isolate the radionuclides from the biosphere. To meet the safe function of isolating waste from the biosphere, while also suppressing the release and migration of radionuclides into groundwater within its designed lifetime, the disposal canister, as the key engineering barriers, should maintain its integrity and avoid failure by corrosion. Thus, it is of great significance to design the corrosion allowance of the canister reasonably. Carbon steels are less susceptible to localized corrosion and mainly corrodes uniformly. The corrosion allowance is acquired by the corrosion rate and lifetime when carbon steels are adopted as materials for canister. The design concept of the corrosion allowance of the canister for high-level radioactive waste in Japan is reviewed in the present work. The possible corrosion forms and the corrosion thickness prediction models of the carbon steel canister in disposal repository are analyzed, and modification suggestions are also discussed, aiming to provide a reference for the corrosion thickness design of the canister.

Corrosion of metallic materials caused by microorganisms in marine environment has been the focus of research and attention. There exist many kinds of microorganisms in marine environment, and the interaction between microorganisms has different influence on corrosion. The corrosion mechanism of mixed microorganisms is often different from that of a single microorganism, and it is difficult to fully explain the actual corrosion situation with the corrosion process of a single microorganism. In-depth study on the synergistic corrosion of metallic materials by different microorganisms has become an important direction in the field of marine microbial corrosion. This paper summarizes the corrosion mechanism of several typical marine bacteria such as sulfate reducing bacteria (SRB), nitrate reducing bacteria (NRB) and iron oxidizing bacteria (IOB) in marine environment and the relevant research progress on these bacteria induced corrosion of metallic materials. The synergistic or antagonistic effects of SRB on the corrosion of metallic materials when it coexists with other microorganisms were comprehensively reviewed, and the different effects of iron oxidizing bacteria (IOB) and nitrate reducing bacteria (NRB) on the corrosion of metallic materials when they coexist with other microorganisms were also summarized in detail. Finally, the direction and suggestions for future research on the microbial corrosion of metallic materials in marine environment were put forward. It aims to provide new inspiration and direction for the research work in this field, and help researchers to better grasp the nature of microbial corrosion, so as to develop more effective anti-corrosion measures.

Alloy steels are widely adopted as structural material in the field of energy and chemical industries, which may encounter atmospheres of high carbon content during service at high temperatures, as a subsequence, often suffer from carbonization-corrosion. Due to the fact that although the existing research covers many common corrosion phenomena, however the overall review of carbonization corrosion is less. Therefore, this paper tries to review the topic of carbonization-corrosion from three aspects : the current research status of carbonization corrosion at home and abroad, the mechanism of carbonization-corrosion, and the counter measures against carbonization-corrosion. The relevant mechanism of carbonization-corrosion encountered in different service environments, such as high-temperature ethylene cracking pipe and supercritical CO₂ unit etc., and the influence of carbonization on the microstructure and mechanical properties of alloy steels were mainly reviewed and analyzed. The counter measures such as adjusting the service environment, optimizing the composition of alloy steels and preparing corrosion resistant coating were discussed. The further research directions related with carbonization-corrosion and protection measures were prospected. At present, carbonization is still the focus of research in the field of energy and chemical industries, especially the carbonization related phenomena existing in new energy equipment systems such as supercritical CO₂ and high-temperature gas-cooled reactors need further study. Protective coating composed of high temperature alloys is one of the effective measures suitable for resisting carbonization corrosion, nevertheless its ability to resist carbonization needs further research.

Microbiologically influenced corrosion (MIC) is a prevalent and serious form of metal corrosion that can cause substantial economic loss. Due to the complexity of the MIC process, developing techniques for detecting and controlling MIC is a key challenge in industrial corrosion science. This paper systematically reviews the research progress of MIC detection methods and prediction models. The detection methods of MIC include electrochemical techniques, bioanalytical methods, radiation detection, microscopy, and biosensing approaches. Each detection technique has its own merits and limitations, and the cooperative application of multiple techniques is needed to comprehensively evaluate the MIC process. The prediction models of MIC can be categorized into those based on risk assessment-based, mass transfer-based, and comprehensive electrochemistry-based models. Given the complexity of MIC systems, no single model has yet been capable of fully predicting MIC phenomena. It is recommended that future efforts be directed toward developing integrated models that account for influential factors and mechanisms, resolving measurements of the microenvironment within biofilms, in order to enhance the accuracy of MIC prediction.

During the service process of a ship, of which different parts encounter different conditions of multi-factor coupling in the real service, which can lead to the premature failure of some materials, posing significant safety hazards to the ship's service life. This article provides an overview of common material failure modes for different parts of ships, with a focus on corrosion failure. It elaborates on the failure locations, forms, and causes of ship hull materials, as well as failure detection methods, and proposes corresponding protective measures.

The corrosion behavior of EH40 marine steel was assessed by means of immersion tests in an artificial seawater at 0 and 25 ℃ for various period respectively Then the variation of corrosion rate, morphology and composition of corrosion products were characterized via electrochemical measurement, scanning electron microscope equipped with an energy dispersive spectrometer, X-ray diffractometer and X-ray photoelectron spectroscopy etc. The results indicated that during the first three days of immersion, the corrosion rate of the steel at 0 ℃ was much higher with the formation fewer pits, which may be attributed to the high dissolved oxygen concentration and the uniform coverage of corrosion products on the steel surface in the low-temperature seawater. As the immersion period extended, the corrosion rate of the steel at 25 ℃ was higher than that at 0 ℃, which may be due to the higher electrochemical activity and less protectiveness of the formed product layer on EH40 steel at 25 ℃. The main iron-containing corrosion products formed at the two temperatures were FeOOH, Fe₂O₃ and Fe₃O₄. However, in the later stages of immersion in the artificial seawater at 25 ℃, precipitates of calcium and magnesium carbonate could form, which mixed with the iron-containing corrosion products to create a corrosion product film, further deteriorating the protectiveness of the rust layer.

To study the influence of Aspergillus aculeatus on the corrosion behavior of Al-alloys, the single colony of Aspergillus aculeatus was isolated and screened from the petri dishes exposed to the coastal atmospheric environment of Hainan Island. The diluted spore suspension of Aspergillus aculeatus with concentration of 1 × 10⁵ /mL was sprayed on the surface of 5A02 Al-alloy samples as groups inoculated with fungi, and sterile control groups were also set up, thereafter, which all placed in a 30 ℃ incubator for selected period of time, while the pH and acid concentration of the bacterial solution were measured intermittently. The test samples were characterized using scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS) in terms of their surface morphology and composition, and the growth of fungi was also observed. The corrosion potential of the Al-alloys surface under the action of Aspergillus aculeatus for different time were analyzed by electrochemical workstation and scanning Kelvin probe (SKP). Results indicated that Aspergillus aculeatus caused localized corrosion of the Al-alloy samples, their corrosion products mainly composed of AlO(OH), Al₂O₃, and MgO. The metabolic activities of Aspergillus aculeatus produced various organic acids, primarily oxalic acid, leading to a trend of decreasing and then increasing in the surrounding pH, thereby promoting the corrosion of the Al-alloy. The range of potential change of the group with fungi was greater, with overall potentials more negative than that of the sterile group. The potential of the group with fungi, initially increased and then decreased with time. The corrosion mechanisms primarily involved fungi metabolite corrosion and oxygen-concentration cell corrosion, while the chloride ions play a role in facilitating the growth of fungi and accelerating the corrosion.

Epoxy resin is a popular choice as the matrix of organic coatings in the metal protection sector. However, the single shielding effect of epoxy coatings is limited. One effective method to improve their protective properties is to add inorganic fillers to epoxy coatings. Coal gangue with a large number of micropores and a high specific surface area, is a rich source of alumina, silica, iron oxide, calcium oxide, magnesium oxide and other components. There are few relevant reports on the application of coal gangue in the field of anticorrosion at home and abroad. Therefore, expanding the application of coal gangue in the field of anticorrosion coating may be of significance in environmental benefits, technical application and innovation. Herein, the impact of coal gangue addition on the performance of epoxy coatings was studied with epoxy resin E44 as matrix and different proportions (1%, 5%, and 10% in mass fraction) of coal gangue as fillers to prepare coal gangue-modified epoxy resin coatings. These coatings were subsequently applied to silica gel plates and Q235 mild steel surfaces, yielding samples of free coating film and coated steel. The average coating thickness was approximately 150 μm. The morphology of coal gangue powders was revealed by means of JSM-7001F field emission scanning electron microscope as that the coal gangue presented multi lamellar structure with an average particle size of 3.18 ± 0.12 μm, which may be conductive to the improvement of the coating properties. Then, a series of tests were conducted to assess the performance of the coating, including a water absorption test, tensile test, adhesion test and electrochemical EIS test. The results showed that the addition of coal gangue to the epoxy resin in proper quantity can enhance the densification, strength, toughness, adhesion and anticorrosive properties of the coatings. However, the performance improvement showed non-linear dependence on the dosage of coal gangue; an excess addition of coal gangue can result in particle agglomeration, which may lead to an increase in defects, and reduction in the protective properties of the coating. For the coating with the addition of coal gangue 5%, the fracture strength reaches 35.30 MPa, the maximum strain reaches 6.13%, and the lower saturated water absorption rate of 2.24% can be obtained after immersing for 10 d. This is accompanied by a loss of adhesion of 58.65%, maintaining the maximum low-frequency impedance modulus value of 3.40 × 10⁸ Ω·cm² and the maximum coating resistance of 6.36 × 10⁷ Ω·cm². The multi lamellar structured coal gangue with large specific surface area and anisotropic multi-orientations of grains, which may be beneficial to the enhancement of the densification, further the mechanical properties, the adhesion, and the anticorrosive properties of the coating as well. The coal gangue serves as a filler, and its additive mass fraction of 5% represents the better performance of the coating. The utilization of gangue in anticorrosive coating represents a novel avenue for the effective deployment of coal gangue and the diversification of filler types in anticorrosive coating. The composition and distinctive microstructure of coal gangue permit the optimization of coating performance through the implementation of appropriate modifications.

The effect of different hydrostatic pressures (0.1, 6, and 12 MPa) on the corrosion behavior of the base metal and welded joint for a GPa-grade offshore engineering steel in a 3.5%NaCl solution was investigated by using linear polarization resistance (LPR), electrochemical impedance spectroscopy (EIS), potentiodynamic polarization, and electrochemical noise (EN) methods. The results indicate that in conditions of various hydrostatic pressures, the corrosion resistance of the base metal of the GPa-grade offshore engineering steel is better than that of the welded joint. Hydrostatic pressure has a minor impact on the cathodic process of both the matrix and the welded joint, but it can promote their anodic dissolution process, thereby accelerating the corrosion rate of both. With the increasing hydrostatic pressure, the local corrosion susceptibility of both the base metal and welded joint of GPa-grade offshore engineering steel was enhanced.

In this study, CeO₂ was synthesized on zirconium metal oxide skeleton (Zr-MOF) material by hydrothermal synthesis with Ce(NO₃)₃ as cerium source, ammonia as precipitant, and ethylene glycol as dispersant. The micro-morphology, structureand chemical composition of the composites were characterized by means of scanning electron microscope, transmission electron microscope, X-ray diffractometer, FTIR spectroscopy, X-ray photoelectron spectroscopy, and specific surface area analyzer. Then, as a filler, different amount of CeO₂@Zr-MOF was mixed with epoxy resin to prepare variouse CeO₂@Zr-MOF-epoxy rein coatings on galvanized steel plate. Afterwards, the effect of CeO₂@Zr-MOF on the protectiveness, mechanical properties and hydrophobicityof the CeO₂@Zr-MOF coatings were investigated via electrochemical test, salt spray test, hardness test, adhesion test, and contact angle test etc. The results show that CeO₂ particles were successfully deposited on the surface of Zr-MOF, while the prepared CeO₂@Zr-MOF has a regular morphology with CeO₂ particles of mean diameter 200 nm uniformly distributed on the surface, which presents a uniform and dense porous structure with pore size ranging 5-20 nm, and average specific surface area of 99.48 m²/g; The hardness of the epoxy resin coating with CeO₂@Zr-MOF is about 11HV, which is about 111% higher than that of pure epoxy resin coating. The adhesion of the coating is about 3 MPa, which is about 18% higher than that of the pure epoxy resin coating, and the contact angle is about 70º for water, which is 12°-14° higher than that of the pure epoxy resin coating; The anticorrosive performance of CeO₂@Zr-MOF epoxy resin coating is significantly better than that of pure epoxy resin coating. Among them, the impedance modulus value of the epoxy resin coating with 1%CeO₂@Zr-MOF is 5.49 × 10¹⁰ Ω·cm² at frequency 0.01 Hz after 60 d of immersion in 3.5% NaCl solution, which is three orders of magnitude higher than that of the pure epoxy resin coating. Furthermore after 400 h of salt spray test, the coating is almost no signs of corrosion, showing better protectiveness for galvanized steel plate

The reuse of reclaimed water as a source of circulating cooling water for thermal power plants is an increasingly common way to save water. However, it has led to troubles such as microbial growth, corrosion and scaling. Herein, the performance of composite agents in scaling inhibition, bactericidal and corrosion inhibition was assessed for commercial Q235 carbon steel in reclaimed water was assessed used as circulating cooling water of thermal power plant via static scale inhibition method, biocide energy efficiency evaluation method, electrochemical and response surface analysis method etc. The test specimens were analyzed in terms of morphology and composition by using SEM, metallography and EDS. The results showed that the optimal formulation of composite chemical agents for the candidate reclaimed water as the recycling circulating cooling water is as follows: scale inhibitor 17 mg/L + biocide 40 mg/L + sodium gluconate 90 mg/L + zinc sulfate 11 mg/L, which presents a scale inhibition rate of 95.7%, a bactericidal effective time of 15 d, and a corrosion inhibition rate of 91.27%. Furthermore, there is a better synergistic effect between the various agents, and the composite agents can inhibit the cathodic and anodic reactions simultaneously. The composite agents can inhibit cathodic and anodic reaction at the same time, which is a kind of hybrid, multi-functional, environmentally friendly agent for cooling circulating water treatment.

The Cu electroplating on sintered NdFeB was conducted with hydroxyethylidene diphosphonic acid (HEDP) as a cyanide-free alkaline plating electrolyte and potassium pyrophosphate as an auxiliary complexing agent. Meanwhile, the plating process was optimized through cyclic voltammetry (CV), cathodic current efficiency, Hall tank experiments, scanning electron microscopy (SEM) and other means; then the plated coatings were characterized by means of SEM and scratch test etc., and their corrosion resistance was assessed by salt spray test. The results showed that the coatings with smooth surface, defect free and good adhesion to the NdFeB substrate may be acquired with an electrolyte composed of CuSO₄·5H₂O 22.5 g·L^-1, HEDP 60 g·L^-1, K₄P₂O₇ 40 g·L^-1 and K₂SO₄ 10 g·L^-1 of pH = 10, at 50 ℃, by stirring rate of 200 r·min^-1, and current density of 0.6 A·dm^-2. The corrosion resistance of the Cu-plating is close to that of conventional Ni-Cu-Ni plating; Besides, the surface magnetic and magnetic flux results show that the magnetic shielding effect of direct Cu plating on NdFeB surface is smaller than that of Ni-Cu-Ni plating.

T-pipe is a common component in high-pressure manifolds, which are in high-pressure environments while subjected to solid particles erosion for a long term, which subsequently affects the safe operation of the relevant system and the service life of pipelines. Herein, the erosion behavior of the high-pressure tee manifold was assessed via a home-made liquid-solid two-phase erosion test bench, which can apply dynamic load on the tested t-pipe subjected to erosion. A model was proposed for description of erosion under dynamic load, and then coupled with a numerical simulation software, to analyze the erosion performance of tee structures at various spatial angles under different internal pressures, velocities, and particle mass flows. Results show that the maximum erosion rate of different tee structures increases with the increase of internal pressure, exponentially with the increase of flow rate, linearly with the increase of particle mass flow rate, and the greater the tee space angle, the faster the growth rate. When the space angle of the tee structure increases, the maximum erosion rate increases, while the erosion performance does not change with the change of internal pressure, velocity, and particle mass flow rate. The results can provide reference for the safe operation of the high-pressure tee manifold.

In order to reveal the erosion wear mechanism of pipeline during conveying iron ore concentrate containing slurry, a method based on the so called “dense discrete phase model” (DDPM) and “response surface methodology” (RSM) is proposed to analyze the erosion wear characteristics of slurry pipeline, and simulate the erosion wear behavior of pipeline caused by iron ore concentrate during the slurry conveying process. Meanwhile, the influence of single factor and multi-factor coupling on the erosion wear of pipeline is also analyzed. Firstly, a computational fluid dynamics (CFD) model is established by combining the actual working conditions of iron ore concentrate transportation; secondly, the accuracy of the E/CRC (Erosion/Corrosion Research Center) erosion model is verified by using the open dataset, which shows that the model can be used to calculate the erosion wear of the slurry pipeline; finally, the effect of inlet velocity, particle size, particle mass flow rate and slurry flow direction on the erosion wear of the pipeline is investigated, and RSM tests are designed to analyze the importance of different factors. The results show that: the erosion rate increases with the increase of inlet velocity, namely, in the range of 1.5-2.0 m/s the pipeline erosion wear is the smallest; with the increase of particle size, the erosion rate shows the trend of decreasing and then increasing, for particle size of 100 μm, hence, the pipeline erosion wear can be effectively reduced; with the increase of the particle mass flow rate, the maximum erosion rate increases first, then decreases, and finally tends to be stabilized; By taking the critical mass flow rate and the economics of pipeline transportation into account, the propriate particle mass flow rate should be selected above 2.5 kg/s. The influence of three flow field factors on pipeline erosion wear is inlet velocity > particle mass flow rate > particle size; under multi-factor coupling, the combined effect of inlet velocity and particle size has the greatest influence on pipeline erosion wear. The method proposed in this study can provide a theoretical basis for pipe erosion protection.

Due to the harsh operating environment, the corrosion problem of gathering and transportation pipelines has become increasingly severe, necessitating the development of an accurate model to predict the internal corrosion rate of such pipelines. Herein, a pipeline corrosion prediction method that combines physics-guided neural networks (PGNN) with an improved particle swarm optimization (IPSO) algorithm is proposed. By analyzing the electrochemical corrosion mechanism, the universal impact of variations in different corrosion factors on the corrosion rate is summarized. Subsequently, based on these universal laws, a loss function characterization method is proposed to construct a physics-guided internal corrosion rate prediction model. The model's hyperparameters are optimized using a particle swarm algorithm improved through reverse learning, nonlinear weight adjustment mechanisms, and cosine algorithm enhancements. Finally, the predictive model is subjected to interpretability analysis using electrochemical corrosion mechanisms, partial dependence plots, and the SHAP algorithm. The accuracy of the model is evaluated using four metrics: mean absolute error (MAE), root mean square error (RMSE), mean absolute percentage error (MAPE), and R-squared (R²), while its reliability is assessed based on its consistency with corrosion mechanisms. Results demonstrate that the PGNN-IPSO method can avoid learning erroneous patterns contradicting physical principles, thereby enhancing prediction accuracy. This research holds significant implications for corrosion protection, reliability assessment, and maintenance decision-making regarding gathering and transportation pipelines.

In order to evaluate the corrosion behavior evolution of aerospace cast Mg-Gd-Y-Zr alloy in coastal storage environments, herein, an accelerated environmental spectrum test method was designed to simulate coastal storage environments based on environmental parameters of several typical southern coastal cities of our country. The corrosion behavior of Mg-Gd-Y-Zr alloy in the simulated coastal storage environment was studied by means of corrosion kinetics, scanning electron microscopy, X-ray diffraction analysis, and electrochemical testing. The results showed that with the progress of corrosion process, corrosion products formed on Mg-Gd-Y-Zr alloy increased gradually, and the resistance R_f of the rust layer continued to increase, while the alloy showed continually a decreasing trend in corrosion rate. The XRD results indicate that the corrosion products are composited mainly of Mg(OH)₂, MgCl₂·6H₂O, MgO, Gd₂O₃, and a small amount of ZrO₂. Correspondingly, the scale of corrosion products on the alloy was gradually divided into two layers, with the outer layer being relatively loose and the inner layer being relatively dense.

The radioactive decontamination of the primary circuit components of the pressurized water reactors (PWRs) is an important process during the overhaul of the nuclear power plant. The effective removal of activated corrosion products on the surface of structural components is directly related to the safety of maintenance personnel. Herein, the X3CrNiMo13-4 steel, used in the main coolant circulating pump of Hualong One PWR, was oxidized in an autoclave to form a pre-oxide scale, as a simulation of the oxide scale formed on its surface in the PWR. Then the influence of the composition of decontamination solution and the process parameter on the removal effectiveness of the simulated oxide scale was compared and analyzed, meanwhile the possible deterioration effect of the decontamination process on the steel matrix was also evaluated using scanning electron microscopy (SEM). The results show that the simulated oxide scale can be effectively removed through alternative treatments of citric acid + DTPA solution cleaning and acidic potassium permanganate oxidation. Compared with alkaline potassium permanganate, the acid potassium permanganate solution has a better removal effect on the corrosion products of the X3CrNiMo13-4 steel without damaging the alloy steel matrix.

A novel self-renewable coating RZn-NMA-X with self-crosslinking properties and antifouling performance was prepared by introducing N-Methylol acrylamide (NMA) into a self-polishing acrylic resin. The coating formed by the combination of a self-polishing resin with a hydrophilic crosslinking network referred to as RZn-NMA-X, exhibited a stable hydrolysis rate and stable film-forming surface in seawater in a 60 d static soaking test. The laboratory bioassay and 150 d marine field test showed that the RZn-NMA-X polymer has good antifouling properties with an optimal content of 5%NMA. In conclusion, the incorporation of an appropriate amount of NMA not only enhances the antifouling performance of the coating, but also provides assurance for its gradual polishing and resistance to biofouling due to its favorable surface characteristics, which is beneficial for enhancing the longevity of marine antifouling in coating applications. The preparation method suggested in this study is straightforward, and the raw materials are affordable and readily available, making it suitable for large-scale production in antifouling applications.

A home-made commercial two-component epoxy primer with a ratio of epoxy paint to curing agent 5:1 was applied on a high-strength Al-alloy plate used for high-speed train. Then the corrosion process of the epoxy primer/Al-alloy was studied in 3.5%NaCl solution by electrochemical impedance spectra. The accelerated aging test was carried out via a chamber with humidity of 95% at 60 ℃ for 60 d, after hydrothermal aging for different times, the change in surface morphology, gloss and color difference of the coating was assessed and the change of chemical bonds of epoxy primer was analyzed. The results show that when the coating was immersed in 3.5%NaCl until 2160 h, the impedance spectra changed a little, indicating a good barrier effect. After 2160 h, the protective ability of epoxy primer started to decline. After 60 d of hydrothermal aging, the surface of epoxy primer became rough due to the decomposition of epoxy resin and falling of the pigments and fillers. Fourier Transform Infrared Spectra of the epoxy primer show that the peak of C-O-C stretching vibration intensified in the first 10 d due to the post curing and then weakened due to the hydrolysis.

7075 Al-alloy plates of 6 mm in thickness were subjected to shot peening treatments with varying parameters. Then the effect of shot peening on the microstructure, surface-roughness and -hardness as well as corrosion performance was assessed, aiming in optimization of the shot pinning processes. The results indicated that shot peening led to grain refinement and work hardening of the shot peened surface. Both the roughness and hardness increased with the increase of the ball diameter and the injection pressure. As the repetition rate of shot peening area increased from 100% to 300%, the hardness increased, while the roughness rose firstly and then decreased. When the ball diameter was 0.1 mm and the injection pressure was 0.3 MPa, the hardness reached 220.7 HV with the repetition rate of 300%, while the roughness reached a minimum value of 0.623 μm with the repetition rate of 200%. In comparison with the single shot peening, the double shot peening may result in significant reduction in surface roughness from 4.131 μm to 2.232 μm, but in slight increment in hardness from 223 HV to 227 HV. Besides, the corrosion potential increased from -0.7276 V for the alloy before shot pinning to -0.6816 V for the alloy after twice shot pinning, indicating that the double peening can significantly enhance the corrosion resistance of the 7075 Al-alloy.

Solid-state reference electrodes were widely adopted to monitor the corrosion of reinforcement and chloride ion concentration in concrete protective layers, which is one of the core components of the durability monitoring equipment for concrete structures. In present, the existing electrodes cannot satisfy all the application requirements of solid-state reference electrodes in concrete environments. Thus, it is important to select solid-state reference electrodes with favorable comprehensive performance. In this article, the repeatability and stability of powder MnO₂ reference electrode, colloidal MnO₂ reference electrode, nickel ferrite (NiFe₂O₄) solid reference electrode, and graphite electrode were compared in simulated pore solution and mortar, respectively. The sensitivities of these reference electrodes also were compared when they were used in multiple operating conditions, such as different temperatures, pH values, oxygen concentrations, and chloride ion concentrations etc. The comprehensive properties of various solid-state reference electrodes were analyzed by weighing method. The results show that the powder MnO₂ electrode has favorable reproducibility and stability, but it was not sensitive to the pH value in the concrete environment. In comparison, the NiFe₂O₄ solid-state reference electrode was insensitive to temperature and oxygen content. In summary, the powder MnO₂ reference electrode displayed the best comprehensive properties in the simulated pore solution. For the short-term testing in mortar, slight differences were observed in the properties of the powder MnO₂ electrode, colloidal MnO₂ electrode, and nickel ferrite electrode, and further research needs to be performed on the long-term performance of the three electrodes in concrete environments.

The corrosion behavior of a pipeline with an inclination of 30° in gas-liquid two-phase flow, the distribution and the inhibition efficiency of corrosion inhibitors were studied by experiment and CFD simulation. The results indicate that in case of the gas phase flow rate of 3 m/s while carrying 7.5vol.% liquid, the gas-liquid two-phase flow in the bent and inclined sections transforms into slug flow, thereby, where become the main areas subjected to corrosion, which is consistent with the detected locations of pipeline leakage at the gas field site. Results of electrochemical test and the fluent simulation indicate that the concentration distribution of corrosion inhibitors at the top and bottom of the pipeline shows a trend of first increasing and then decreasing along the pipeline axis, the concentration at the bottom of the pipeline is higher than the corresponding concentration at the top of the corresponding part. The corrosion rate of the electrode in the inclined section is the highest, indicating the minimum coverage of the corrosion inhibitor at the inclined section.

By incorporation of reduced graphene oxide-carbon nanotubes (RGO-CNTs) in the oxide mixture RuO₂-IrO₂-SnO₂ to prepare RGO-CNTs doped RuO₂-IrO₂-SnO₂/Ti anode via multiple coating -calcination process. Then the surface morphology, structure, phase composition, and electrocatalytic activity of the anodes prepared at different calcination temperature were characterized by means of SEM, EDS, XRD, and electrochemical techniques, accordingly their electrolysis lifetime enhancement were also assessed. The results demonstrate that uniformly dispersed hybrid RGO-CNTs in the precursors still remain partially as elemental form in the acquired calcinates, with the increasing calcination temperature, the RGO-CNTs amount in the calcinates decreases. The doped RGO-CNTs can alleviate the thermal stress generated within the coating at high temperatures, improving the surface morphology of the anode with fewer and smaller thermal crack defects. Moreover, with the increasing calcination temperature, the doped RGO-CNTs may facilitate the precipitation of active RuO₂ and IrO₂ grains, enhancing the content of Ru and Ir in the coating, thereby enhance the electrolysis lifetime by 10%-30%, and voltammetric charge by 18.95%-26.57%. Consequently, the doped RGO-CNTs hybrid material can enhance the corrosion resistance and electrocatalytic activity of the metal oxide anode, therefore prolong its service life.

Electro-galvanizing is one of the most widely used methods in the field of corrosion prevention for steels, but during the service, the galvanized layer is prone to friction and wear. This article attempts to optimize the plating process by adjusting the electrode layout and bath temperature, thereby, novel WC-Zn composite coatings were then electrodeposited on the surface of Q235 steel, aiming in the improvement of the corrosion resistance and friction-wear property of the steel substrate. Meanwhile, the morphology, structure, and electrochemical characteristics of the acquired coatings were characterized by means of scanning electron microscopy (SEM), X-ray diffraction (XRD), hardness measurement, and electrochemical testing. The results showed that compared with conventional left and right electroplating, the up and down electroplating method can significantly increase the content of WC particles in the composite coating. When the increasing electrolyte temperature, the WC content in the coating formed by the up and down electroplating method is significantly increased. At 60 ℃, the WC content in the coating is as high as 43.2%, while the WC particles were uniformly distributed on the surface of the coating. In addition, the addition of WC particles improves the hardness of the coating, and the free-corrosion current density of the electrode of WC-Zn/Q235 steel gradually decreases with the increase of WC content in the WC-Zn composite coating.

The tribo-corrosion performance of 7075-T6 Al-alloy in 3.5% (mass fraction) NaCl solution was studied, while the variation of the passivation film and the tribo-corroded surface was also examined versus the tribo-corrosion process. The results demonstrate that sliding friction leads to a decrease in the open-circuit potential (OCP) and the potentiodynamic polarization corrosion potential of Al-alloy, whereas, a significant increase in the corrosion current density. In constant cathodic potential condition, the passivation film was removed due to the friction, accelerating the hydrogen evolution reaction. In constant anodic potential condition, friction leads to a significant increase in corrosion current density, accelerating the corrosion of the alloy. XPS analysis result indicates that the primary constituent of the passivation film is Al₂O₃. In conditions of dry sliding friction, OCP, constant anodic potential, and constant cathodic potential, respectively, the values of friction coefficient and wear rate can be ranked as the following decline order: dry sliding friction>constant anodic potential> OCP>constant cathodic potential. The wear mechanism in dry sliding friction condition is adhesive wear, the wear mechanisms in OCP and constant cathodic potential conditions are abrasive wear, and the wear mechanism in constant anodic potential condition is corrosive wear.

In recent years, the fluorescence detection technology has become the main methods of on-line detection for scale inhibitors. Then, fluorescence-type scale inhibitors play a key role in the above inspection, and its research work is need urgently. Herein, novel composite carbon dots (AA-CD_M) of acrylic acid-motherwort dregs, which was synthesized using a one-step hydrothermal method with motherwort dregs and acrylic acid as raw materials. Then, the rationality of AA-CD_M synthesis process was confirmed by infrared spectrum and X-ray photoelectron spectroscopy. In the anti-scaling aspect, the results of scale inhibition test showed that the AA-CD_M presents remarkably enhanced scale inhibition efficiency, which is attributed to the introduction of acrylic acid into the motherwort-dregs-based. The inhibition efficiency of AA-CD_M in low concentration (5 mg·L^-1) for CaSO₄-type scale was close to 100%, and what is more, which may be retained above 95% origin level, even in 45 h after the first use. Besides, the relevant anti-scaling mechanism of AA-CD_M was analyzed, the outcomes of XRD, XPS, and ultraviolet differential spectroscopy exhibit that AA-CD_M has the chelating solubilization ability, which can inhibit the normal growth of CaSO₄ scale. Meanwhile, the fluorescence intensity of AA-CD_M showed a linear correlation with its concentration (R² = 0.999), and the material presents has also good in thermal stability of fluorescence. Overall, the AA-CD_M is suitable for most circulating water systems, and remains design method to get a novel fluorescent scale inhibitor.

The polar climate environment is special, and metal materials may be exposed to ice cover for a long time. Herein, the effect of variable- and constant-temperature on the corrosion behavior of a Ni-Cr-Mo-V high-strength steel under ice cover conditions was studied. Therefore, an indoor simulation test procedure was proposed as follows: periodic corrosion tests beneath ice cover were conducted at variable temperatures ranging from -45 to -5 ℃ for one month, meanwhile the corrosion tests beneath ice cover at constant temperatures in the range of -5 and -45 ℃ were tacked as comparison. The results show that under the ice cover, the corrosion rate of high-strength steel increases with the increase of temperature; while the variable temperature has a relatively small impact on the corrosion morphology of high-strength steel; Electrochemical test results reveal that the capacitance arc radius of high-strength steel is relatively large, with a small range of variation. At low temperature -5 ℃, its self-corrosion potential is the lowest, but the difference is not significant compared to those by variable temperature conditions; XRD and Raman spectroscopic analysis indicate that the corrosion products are composed of α-FeOOH, β-FeOOH, γ-FeOOH, and Fe₃O₄/γ-Fe₂O₃. The temperature ranges from -45 ℃ to -45--5 ℃, and then to -5 ℃, the spicies of phase for corrosion products are showing an increasing trerd.

The corrosion kinetics and corrosion mechanism of Zn-Al alloy coated steel wire for 2100 MPa bridge cable in neutral salt spray environment were studied by means of electrochemical testing, corrosion loss measurement, scanning electron microscopy (SEM), X-ray diffractometer (XRD), ultra-depth of field microscopy (SDM) etc. The results show that the corrosion products of Zn-Al alloy coated steel wire are mainly composed of Zn(OH)₂ and Zn₅(OH)₈Cl₂·H₂O, and a small amount of Al(OH)₃ and Fe₃O₄. The corrosion behavior can be divided into four stages: the dissolution process of passivated film, the dissolution process of zinc-rich phase, the dissolution process related with the transition interval of zinc-rich phase and eutectic phase, and the dissolution process of Zn-Al eutectic phase. During the test period, the polarization resistance R_p of the Zn-Al alloy coating decreases first and then increase, indicating that its corrosion resistance becomes weak first and then becomes strong. In other word, the corrosion rate of the steel wire increases first and then decreases. There is no obvious corrosion pits formed on the steel wire matrix and no red corrosion products on the surface of the sample. The regression analysis of the corrosion-time curve shows that the corrosion rate increases slowly with the extension of the test time, indicating that the corrosion products have a delaying effect on corrosion, therefore, the Zn-Al alloy coated steel wire has a good corrosion resistance in the neutral salt spray environment.