Protection Of Steel Research Articles

Protection of 316L Steel Against LBE Corrosion by a CaO-MgO-Al2O3-SiO2 Glass–Ceramic Coating

A CaO-MgO-Al2O3-SiO2 glass–ceramic coating was prepared by the slurry method and subsequent sintering to improve the corrosion resistance of 316L steel in liquid lead–bismuth eutectic alloy at high temperatures. The glass–ceramic coating, sintered at 884 °C, was dense and demonstrated strong adhesion to the substrate. It was composed of the crystalline phases diopside (CaMgSi2O6) and anorthite (CaAl2Si2O8) and had an average Vickers hardness of 595 HV, which was over three times that of 316L steel. After corrosion in an oxygen-saturated, static lead–bismuth eutectic alloy at 500 °C for 1000 h, the uncoated 316L experienced significant mass gain (0.04 g) due to severe oxidative corrosion, resulting in the formation of Fe3O4 and Pb2O on its surface. In contrast, the glass–ceramic-coated specimens showed a very small mass gain (0.0012 g) after corrosion. The coating maintained good thermal stability; its crystalline phase composition remained largely unchanged after the corrosion test. The glass–ceramic coating still exhibited dense microstructure and tightly adhered to the substrate after corrosion. There was no evident penetration of lead–bismuth into the coating, and no dissolution of the coating’s elements into the lead–bismuth alloy was detected. These observations confirm that the glass–ceramic coating possessed superior corrosion resistance in liquid lead–bismuth eutectic environments.

Corrosion Behavior of High-Pressure Cold-Sprayed Zn30Al Alloy Coating on Q235 Steel

This study employed a high-pressure cold spray to apply a Zn30Al alloy coating to Q235 steel substrates to provide corrosion protection for steel in marine environments. The corrosion resistance of the coatings was investigated through full immersion tests, and the corrosion mechanisms were further analyzed using electrochemical experiments. The results were compared with those of traditional flame-sprayed Zn30Al alloy coating. The findings indicate that the high-pressure cold-sprayed Zn30Al alloy coating possesses a dense microstructure with a porosity of only 0.32%, providing effective cathodic protection to the substrate during the immersion tests. The cold-sprayed Zn30Al alloy coating maintained good integrity after 720 h immersion in 3.5 wt.% NaCl solution, whereas the flame-sprayed Zn30Al alloy coating exhibited significant pitting corrosion.

Enhanced hydrophobicity of polyurethane coating for steel protection through replication and nanomaterial integration

Polyurethanes (PU) are widely used in corrosion protection, anti-biofouling coatings, and self-cleaning glass, yet their low hydrophobicity poses durability challenges. This study addresses this by enhancing PU coatings’ hydrophobicity by refining surface roughness and forming tailored porous structures. Using drop, spin, dip, and spray coating techniques, hydrophobic PU coatings were fabricated on 304 steel plates. To further enhance hydrophobicity, 0.5 w/v% graphene nanoplatelets (GNP) were introduced into the coatings. Additionally, stainless-steel 500 mesh was incorporated to create patterned surfaces, increasing surface roughness and tailoring the porous structure. The analysis included optical and scanning electron microscopy, water contact angle (WCA) measurements, Fourier transform infrared spectroscopy, electrochemical corrosion tests, and atomic force microscopy. Incorporating GNP notably increased WCA by 20–23° and reduced corrosion rates in a 3.5% NaCl solution. Likewise, applying stainless-steel mesh improved surface roughness, raising WCA by 3-8° and decreasing corrosion rates. The study observed changes in porous structure, with pore size reduction correlating with increased roughness and decreased corrosion rates upon mesh application and GNP addition. This comprehensive examination highlights the potential of PU coatings for various applications and underlines the importance of tailored porous structures in enhancing their performance and versatility. Spin coating emerged as the optimal technique, yielding uniform, defect-free coatings with the highest WCA.

A comprehensive investigation of oxygen/graphite carbon nitride smart Nano coatings for sustainable maintenance and sacrificial anode protection of mild steel

AbstractBACKGROUNDThis study enhancing the corrosion resistance of mild steel (MS) by incorporating photo‐catalyst‐doped graphitic carbon nitride (g‐C₃N₄) nano‐sheets containing silver (Ag) and oxygen (O₂) into a solar light‐active photoelectrochemical anticorrosion paint with polyester (PE). The objective is to provide sacrificial anode protection through visible light activation.RESULTSThe developed paint forms a uniform film on the MS surface, effectively providing anodic protection under visible light. Characterization techniques, including energy‐dispersive X‐ray spectroscopy (EDX), transmission electron microscopy (TEM), Fourier‐transform infrared spectroscopy (FTIR), and UV–Vis spectroscopy, confirm the molecular structure of the nano‐sheets. Corrosion resistance, assessed through weight loss measurements and open circuit potential (OCP) tests, shows significant improvement with the addition of Ag/g‐C₃N₄ and Ag‐O₂/g‐C₃N₄ nano‐sheets at an optimized concentration of 15 mg. The protection efficiency is ranked as follows: O₂‐g/C₃N₄ > O‐g/C₃N₄ > Ag‐O₂/g‐C₃N₄ > Ag‐g/C₃N₄ > g‐C₃N₄. After 28 days of immersion in seawater, MS coated with O₂/g‐C₃N₄ exhibited the least weight loss, with an inhibition efficiency of up to 99%. Electrochemical impedance spectroscopy (EIS) further demonstrated enhanced coating resistance for the O₂/g‐C₃N₄ coating (Rct = 3.76 kΩ.cm2, Rcoat = 1.69 kΩ.cm2) compared to pure PE (Rct = 0.005 kΩ.cm2, Rcoat = 0.096 kΩ.cm2).CONCLUSIONThe synthesized O₂/g‐C₃N₄ and Ag‐O₂/g‐C₃N₄ nano‐sheets exhibit high surface areas and enhanced water dispersibility, which contribute to significant corrosion protection of MS. The electrochemical performance, including weight loss and OCP measurements, highlights the potential of these nano‐sheet photo‐catalysts in advancing corrosion resistance technologies, with broad implications for materials science and engineering applications. © 2024 Society of Chemical Industry (SCI).

Corrosion protection performance of poly(PyM-co-GMA)/SWCNT nanocomposites coating on mild steel

Recently, there has been significant emphasis on developing electroactive functional methacrylate polymers for anticorrosive applications. In this context, we have synthesized Poly[(3,5-dimethyl-1H-pyrazole-1-yl) methyl methacrylate-co-glycidyl methacrylate] [Poly(PyM-co-GMA)] and its nanocomposite with single- walled carbon nanotubes (SWCNTs) [Poly(PyM-co-GMA)/SWCNT]. The resulting materials were characterized using Fourier Transform Infrared spectroscopy (FT-IR) and X-ray Diffraction analysis (XRD). Morphological changes due to the incorporation of SWCNTs were examined using field-emission scanning electron microscopy (FE-SEM) and high-resolution transmission electron microscopy (HR-TEM). The optical properties of Poly(PyM-co-GMA) and Poly(PyM-co-GMA)/SWCNT (0.5, 1.0, and 1.5 wt. %) were investigated. The thermal behavior of Poly(PyM-co-GMA) and its SWCNT nanocomposites was analyzed through thermogravimetric analysis (TGA). The anticorrosive performance of the prepared materials was evaluated on a mild steel substrate (MS) in a 3.5% (w/v) NaCl medium using electrochemical techniques. Results from potentiodynamic polarization and electrochemical impedance spectroscopy indicate that the Poly(PyM-co-GMA) and Poly(PyM- co-GMA)/SWCNT coatings (0.5, 1.0, and 1.5 wt. %) provide effective barrier protection for mild steel against marine environments.

How does the integration of amino acids enhance the bonding ability of triazine-based inhibitors with iron surfaces: Insights from SCC-DFTB, COSMO-RS and molecular dynamics simulations

Theoretical investigations into the adsorption of molecules on metal surfaces play a pivotal role in the development of more efficient corrosion inhibitors. This study offers a novel approach by combining Density Functional Tight Binding (DFTB), Molecular Dynamics (MD) simulations, and conductor-like screening model for realistic solvation (COSMO-RS) calculations to comprehensively assess the interaction and diffusion properties of glycine (Gly), 2,2′-azanediyldiacetic acid (IDA), and 5-aminopentanoic acid (5-APA) with two 1,3,5-triazine (Tris) derivatives (Tris-Gly and Tris-IDA) for corrosion protection of carbon steel in acidic medium. The solvation properties of these molecules were evaluated alongside their interaction strength with the Fe(1 1 0) surface, considering both neutral and protonated forms. DFTB simulations revealed a clear trend in interaction energies, following the order: Tris-IDA > Tris-Gly > 5-APA > IDA > Gly. It ranges from −1.191 eV to −1.853 eV, with the highest stability observed for protonated Tris-IDA (−1.853 eV), while neutral Glycine exhibits the lowest interaction energy (−1.263 eV). While these theoretical results diverged slightly from experimental observations, with Tris-Gly outperforming Tris-IDA, this discrepancy was attributed to steric effects and solvent interactions. The DFTB results also indicated strong covalent interactions, particularly involving acetic groups, between the inhibitors’ orbitals and the iron’s 3d orbitals. MD simulations further demonstrated the impact of protonation on inhibitor mobility, with reduced diffusion coefficients due to enhanced electrostatic interactions and hydrogen bonding. COSMO-RS solvation analysis confirmed the strong hydrogen bonding capabilities of these molecules with water. Overall, this study elucidates the mechanisms of corrosion inhibition by integrating multiple simulation techniques, providing key molecular insights that can guide the design of more effective corrosion inhibitors. The findings emphasize the significance of electronic interactions and molecular structure in enhancing inhibitor performance, making this a valuable contribution to corrosion science.

Eco-friendly Chlorella vulgaris extracts for corrosion protection of steel in acidic environments

This study evaluates the potential of Chlorella vulgaris sp. extracts as eco-friendly corrosion inhibitors for API 5L 42 Steel in a 1M HCl acidic environment, offering sustainable alternatives for industrial applications. Two corrosion inhibitors were obtained through solvent extraction methods: M1 (methanol) and M2 (methanol/chloroform). The extracts were characterized using infrared spectroscopy, the analysis revealed hydroxyl, methyl and vinyl groups as the most representative. The effect of corrosion inhibition was study by electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization. The results show significant reductions in corrosion current density and increases in charge transfer resistance, with M2 achieving the highest protection efficiency of 91.20 % and a charge transfer resistance of 501.80 Ω at a 120 ppm concentration, while M1 reached 88.22 % efficiency with a charge transfer resistance of 102.30 Ω. Uv–Vis measurements were performed to determine the electronic transitions of the metal-inhibitor system for each of the extracts. ANOVA highlighted the significant influence of biomass concentration on corrosion resistance. The adsorption of M1 and M2 extracts on the carbon steel surface obeyed the Langmuir isotherm and Gibbs free energy calculations indicated a physisorption mechanism for both extracts. Surface morphology analysis by Scanning electron microscope (SEM) revealed less pitting and reduced surface roughness as inhibitor concentration increased. These findings underscore the potential of Chlorella vulgaris extracts, particularly M2 at 120 ppm, as effective and sustainable corrosion inhibitors for steel in acidic environments.

Protection of steel in solutions of sulfuric and phosphoric acid by inhibitors based on pharmaceuticals

Protection of steel in solutions of sulfuric and phosphoric acid by inhibitors based on pharmaceuticals

Anti-corrosion protection of steel with superhydrophobic coatings based on nickel and zinc

Anti-corrosion protection of steel with superhydrophobic coatings based on nickel and zinc

Complex Protection of Some Steels in Sulfuric Acid Solutions by 1,2,4-Triazole Derivatives.

The corrosion behavior of steels of various grades in sulfuric acid solutions with the addition of nitrogen-containing corrosion inhibitors has been studied. Compounds containing the 1,2,4-triazole moiety effectively protect low-carbon (St3, St20, 08PS), high-strength (70S2KhA), and stainless steels (1Kh18N9T) not only from corrosion but also from the hydrogen penetration into the metals in concentrated sulfuric acid solutions. In some cases, the degree of steel protection from corrosion by these compounds exceeded 99%. The possibility of creating mixed inhibitors for steel protection containing triazole derivatives and KI has been shown. The rate constants for the main steps of cathodic evolution and hydrogen penetration into steel in sulfuric acid solutions have been determined, and the subsurface concentrations of hydrogen in the metals have been calculated. Triazole derivatives were found to act as inhibitors of hydrogen absorption by steel in H2SO4 solution. The degree of protection of steel from hydrogen absorption can reach 97%. It has been shown that triazole derivatives act as complex inhibitors of steel corrosion in sulfuric acid solutions because, along with strong inhibition of metal corrosion, they prevent hydrogen absorption by steel.

A multianalytical approach to benzodiazepine derivatives for the corrosion protection of mild steel in HCl solutions: Electrochemical analysis, SEM/EDX, XPS, DFT, and MDS calculations

A multianalytical approach to benzodiazepine derivatives for the corrosion protection of mild steel in HCl solutions: Electrochemical analysis, SEM/EDX, XPS, DFT, and MDS calculations

Corrosion protection of mild steel via cerium nitrate loaded acrylic-vinyl polysilazane based hybrid coatings

This study presents an efficient anticorrosive coating based on an organic-inorganic hybrid polymer composed of methyl methacrylate, styrene, tert-butyl acrylate, and vinyl polysilazane. The synthesized resin exhibits excellent thermal resistance and stability, as confirmed by thermogravimetric analysis (TGA). Additionally, leveraging the resin's highly alkaline nature, cerium oxide (CeO2) nanoparticles were doped in situ within the polymer matrix. The hybrid resins were subsequently applied to mild steel panels using a dip-coating technique. The resulting coatings are transparent, flexible, thin, pore-free, and possess low surface roughness (<2.62 nm), along with good thermal stability (>350 °C). Their remarkable anticorrosive performance and durability are attributed to forming a highly crosslinked acrylic-polysilazane network, combined with a cerium oxide protective barrier layer that adheres to the substrate. Furthermore, the cerium ions suppress both cathodic and anodic corrosion reactions, enhancing the corrosion resistance. Notably, the coating system containing 2 wt% cerium achieved a high impedance value of 106 Ω cm2, corresponding to a corrosion rate of 0.112 × 10−5 mm/year. This study demonstrates that these acrylic-vinyl polysilazane coatings, incorporating ceria as a corrosion inhibitor, offer a promising alternative to conventional protection systems.

Corrosion performance and mechanism of clay-lignin biocomposite: Effective bio based coating with strong adhesion character for extended carbon steel protection

The development of sustainable and eco-friendly anticorrosion coating for metal substrates is a pivotal advancement in various engineering fields. Hence, the novel sepiolite-lignin (SP-L) and bentonite-lignin (BN-L) biocomposites were successfully introduced in an alkyd resin 5.0 wt% and applied on carbon steel (CS), to prepare the alkyd SP-L (A/SP-L) and BN-L (A/BN-L) coatings. Particle size and zeta potential measurements were conducted to determine the average particle size and assess the stability of the reinforcing pigments. The corrosion performance of A/SP-L and A/BN-L coatings revealed higher protection with an impedance modulus of about 5.18 × 105 Ω.cm² and 7.86 × 105 Ω.cm², respectively, after 6weeks of immersion in 3 % NaCl solution, measured by electrochemical impedance spectroscopy (EIS), which were extremely higher than the reference alkyd (RA) 1.13 × 103 Ω.cm². The adhesion of the three coated samples before and after immersion was assessed using pull-off test, while their hydrophobicity and impermeability were evaluated using saline corrosion and water absorption tests. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were utilized to examine the corrosion mechanism. The results demonstrated an excellent coating quality and interfacial adhesion against corrosion.

Biopolyurethane coatings with silica-titania microspheres (MICROSCAFS®) as functional filler for corrosion protection

In this work, we studied a biopolyurethane (BioPU) coating derived from a bio-based polyol and isocyanate for the protection of carbon steel against corrosion. The direct utilization of polyols obtained from raw biomass represents a novelty in polyurethane coatings production. The protective properties of these coatings were enhanced by incorporating unique silica-titania (ST) MICROSCAFS®, which are microspheres exhibiting interconnected macro- and mesoporosity. They were loaded with tannic acid (TA), an eco-friendly corrosion inhibitor. Confirmation of TA loading into the ST carriers (therefore called ST\\TA) was achieved through Attenuated total reflectance - Fourier-transform infrared spectroscopy (ATR-FTIR) and Thermogravimetric (TG) analyses. TG analysis revealed that ST\\TA particles contain approximately 34 wt% TA, and their average particle diameter is approximately 25 ± 5 μm, observed by SEM. The TGA shows slightly improved thermal resistance of the coatings modified with the filler MICROSCAFS®. Furthermore, it was observed that the fillers strengthened the coating hardness without negatively affecting the adhesion strength. Electrochemical Impedance Spectroscopy (EIS) results demonstrated that all modified coatings exhibited very good to excellent resistance in mild corrosive environments. The coatings maintained a high impedance modulus (|Z|) at low frequencies and phase angle values close to −90° across a wide frequency range, over an immersion period of 80 days in a 0.05 M NaCl solution. After 80 days of immersion, the best coating, BPU-ST\\TA, displayed |Z| of 3 × 1010 Ω cm2. Scanning Vibrating Electrode Technique (SVET) analysis revealed the inhibitory behaviour of TA. For the BPU-ST\\TA sample, inhibition of both anodic and cathodic activities was clearly visible, with a significant reduction of the current densities starting at 1 h and up to at least 24 h of immersion. In summary, the BioPU coatings modified with tannic acid-loaded MICROSCAFS® exhibit improved barrier properties and notable corrosion inhibition capacity in mild corrosive environments.

Influence of Al2O3 content on microstructure and oxidation resistance of glass-ceramic coatings for 06Ni9DR alloy steel

Glass-ceramic coatings with different Al2O3 content were prepared for oxidation protection of 06Ni9DR alloy steel. The microstructure and oxidation protection rate of coatings with different content of Al2O3 at 1200 °C were investigated. The results showed that the average internal pore size decreased with Al2O3 content and the protection of the coating increased after oxidation test for 3 h. The oxidation protection rate of coating with 20 wt% Al2O3 was the worst due to many large-size pores in the coating and bad thermal stability, and the melting of FeO into the liquid phase accelerated the formation of cracks inside the steel and further deteriorate the oxidation protection. As the alumina content increased, the liquid phase in the coating significantly decreased, and correspondingly the thermal stability increased; At the same time, a large number of 0.5–3 μm pores were formed in the coating, which effectively prolonged the oxygen diffusion path, further enhanced the oxidation resistance of the coating. The glass-ceramic coating with 80 wt% Al2O3 exhibited good oxidation protection, reaching 73.6 ± 1.6 % at 1200 °C for 3 h.

Coating effect of polyurethane-layered double hydroxide nanocomposite on steel

The motivation behind this work is the preparation of polyurethane-magnesium aluminum layered double hydroxide (PU-LDH) nanocomposite and its application as a coating for steel protection. The coating was prepared with different doses of LDH, ranging from 0 to 2% of the coating weight. The effect of different concentrations on the mechanical, adhesion, and surface properties of PU coating is studied. Firstly, LDH was prepared via the coprecipitation process and then distributed in PU matrix. The nanocomposites were then crosslinked in the form of coating layers on steel. The preparation of the thermally stable crystalline LDH nanoparticles with 89 nm particle size was confirmed by FTIR, XRD, DLS, and TGA. SEM photos showed the dispersed and intercalated structure. The coating characteristics demonstrate that addition of LDH decreased the drying time and increased the dry film thickness of PU up to 1.5% due to the crosslinking between the large surface area nanofiller and polyurethane matrix. Furthermore, the prepared LDH nanofiller increased the adhesion strength, impact resistance, abrasion resistance, modulus, and flexibility of PU due to the strong polymeric network structure. The 2% nanocomposite coating shows poor properties due to the excess concentration and heterogeneous dispersion of nanoparticles within the PU polymer. The resistance to fire and some chemicals was supported by the thermally and physically stable LDH nanoclay. The former characterizations state that the proposed PU-LDH nanocomposite is an enhanced and applicable coating.

Development and performance evaluation of green superhydrophobic coating for fouling and corrosion protection

In this paper, a simple and environmentally friendly superhydrophobic stearic acid-modified zinc-nickel-cobalt composite coating (SA@ZNC) is presented. The zinc-nickel-cobalt (ZNC) coating with petal-like micro/nano-rough structure was constructed on the metal surface by combining electrodeposition and chemical substitution techniques. Subsequently, the coating was modified with low surface energy by adding stearic acid, and the SA@ZNC coating with excellent superhydrophobicity (water contact angle of 161.08 ± 0.31° and rolling angle of 3.50 ± 0.54°) was prepared. The coating is self-cleaning against a wide range of simulated contaminants and can remain superhydrophobic in air for over a year. Changes in pH do not significantly affect the superhydrophobicity and at low temperatures, the freezing time of water droplets on the coating was extended by 2.1 times compared to a blank steel sheet. Furthermore, the SA@ZNC coating demonstrated remarkable robustness, withstanding 30 minutes of water impact, a wear mass of 0.2 % after rubbing with weights over 2400 mm and retaining its superhydrophobicity after 80 tape stripping cycles. The results of the corrosion protection tests demonstrated that the SA@ZNC coating provided excellent corrosion protection for N80 steel, exhibiting a current density two orders of magnitude lower than that of the blank sample. Furthermore, the coating exhibited a corrosion inhibition rate of 95.75 ± 0.33 % and excellent charge transfer resistance. The multiple protection mechanisms and homogeneous micro/nanostructure of the coatings resulted in significantly better corrosion resistance than most of the reported zinc-nickel based coatings. The use of low-energy consumption methods and environmentally friendly modifiers positions this coating for large-scale production and potential applications in sectors like food and medicine, with promising implications for corrosion protection in various industries.

Alkylphenyl-substituted imidazolines as corrosion inhibitors: experimental and DFT study

A series of steel corrosion inhibitors based on poly(alkyl-phenyl)-2-imidazolines was synthesized from available reagents. Electronic parameters that influence binding to a metal surface have been determined, and the influence of substituents on the geometry of binding to the surface has been studied. The resulting compounds have a degree of protection of steel in hydrochloric acid solutions in individual form above 98% at 60 °C and in a mixture with urotropine more than 99% at 95 °C.

(La0.2Ce0.2Gd0.2Er0.2Sm0.2)2Zr2O7 High-entropy ceramic-glass composite coating with a high corrosion resistance

In this work, a new type of high-entropy ceramic powder (La0.2Ce0.2Gd0.2Er0.2Sm0.2)2Zr2O7 was synthesized by sol-gel method and high-temperature sintering (1000 °C) method. Combing (La0.2Ce0.2Gd0.2Er0.2Sm0.2)2Zr2O7 and glass powder to prepare high-entropy ceramic-glass composite coating. The composite coating exhibits excellent seawater corrosion resistance and high-temperature resistance performance. The impedance values of composite coating are 2.36 × 106 Ω cm2 in 3.5 % NaCl solution for 24 h. The high-entropy ceramic-glass composite coating could withstand the high temperature of 600 °C for 30 days and remains tight and intact with stainless steel without falling out. This work shows that the (La0.2Ce0.2Gd0.2Er0.2Sm0.2)2Zr2O7-glass composite coating can provide long-term high-temperature and seawater corrosion protection for stainless steel and has good application prospects in the field of marine corrosion protection.

Highly Efficient and Water-Soluble Substituted Pyridinyl Ethyl Urea Inhibitors for the Protection of Mild Steel in Acidic Medium: An Experimental, DFT, and Molecular Dynamics Studies

Highly Efficient and Water-Soluble Substituted Pyridinyl Ethyl Urea Inhibitors for the Protection of Mild Steel in Acidic Medium: An Experimental, DFT, and Molecular Dynamics Studies