Good Anti-corrosion Performance Research Articles

Self-healing epoxy coating based on tung oil-containing microcapsules for corrosion protection

In this work, urea-formaldehyde (UF) microcapsules loaded with tung oil were prepared by in-situ polymerization. The mean diameter of the obtained microcapsules was 8.5 μm. The self-healing coating was prepared by the addition of 5 wt.% microcapsules into an epoxy matrix and then painted on the AA2024 substrate. The effect on the coating properties after the incorporation of microcapsules was investigated by adhesion tests and electrochemical impedance spectroscopy (EIS). It is found that 5 wt.% microcapsules in coating formulations did not impart a significant negative effect on coating properties. SEM and EIS tests were used to evaluate the self-healing effect. According to the fitting results of the EIS data on the scratched samples, the new film that formed by the polymerization of tung oil at the scratched area in the self-healing coating displays a resistance value of more than 106 Ω·cm2, which is much higher than 103 Ω·cm2 of the oxide layer in the neat epoxy coating. The neutral salt spray tests also confirm the good anti-corrosion performance of the self-healing coating.

Green synthesis of corrosion inhibitor with biomass platform molecule: Gravimetrical, electrochemical, morphological, and theoretical investigations

Considering the concept of green chemistry and the vision of human sustainability, a new corrosion inhibitor named N1-(2-aminoethyl)-N2-(2-(2-(furan-2-yl)-4,5-dihydro-1H-imidazol-1-yl) ethyl) ethane-1,2-diamine (NNED) is synthesized from biomass platform molecules. Both weight loss and electrochemical measurements demonstrated that the corrosion inhibitor had good anti-corrosion performance for carbon steel in 1 M HCl medium, with inhibition efficiency higher than 90% at lower level of inhibitor concentration (5 ppm). The adsorption of NNED on the steel surface was spontaneous and obeys the Langmuir adsorption isotherm. The corrosion morphology was studied by scanning electron microscopy (SEM) and atomic force microscopy (AFM). Force-distance curve directly quantified the adhesion force between the adsorption films and the metal surface. Quantum chemical calculation and molecular dynamics simulation were applied to study the corrosion inhibition mechanism.

Corrosion behavior and mechanism of FeCrNi medium entropy alloy prepared by powder metallurgy

The corrosion behavior and mechanism of a novel FeCrNi medium entropy alloy (MEA) prepared by powder metallurgy method in 3.5 wt% NaCl solution was investigated in this study. The results indicated that, compared with the 316L SS, the FeCrNi MEA exhibits outstanding corrosion resistance with a more positive breakdown potential (0.982 VSCE) and lower current density (8.317×10−8A/cm2). The passive film formed on the surface of the FeCrNi MEA is a Cr-riched and less defective film. At the same time, it also has a strong self-healing ability. Uniform microstructure and high Cr content are responsible for the good anti-corrosion performance.

Organic carbon dot coating for superhydrophobic aluminum alloy surfaces.

A novel fluorine-free and silicon-free superhydrophobic aluminum alloy (treated-Al) is fabricated by chemical etching using hydrochloric acid and hydrogen peroxide and modified with an organic carbon dot (OCD) coating. The water contact angle (CA) of the treated-Al surface increases with the OCD concentration. When etched aluminum (etched-Al) is modified with 0.5 mg/ml OCDs, a CA of 161.4° is achieved, which indicates good nonwettability. SEM results verify that porous microstructures with cavities are uniformly distributed on the surface of etched-Al, in contrast to the bare aluminum alloy, which forms a primary rough structure. After treatment with 0.5 mg/ml OCDs, a nanoparticle coating is dispersed on the rough structures of treated-Al-0.5, which can trap air and make a water droplet essentially rest on a layer of air. The treated-Al-0.5 material has good self-cleaning properties and can sweep away contaminants at both 20 and 0°C. The Ecorr and Icorr of treated-Al-0.5 are − 0.56 V and 2.82 × 10−6 A/cm2, respectively, which shows good anticorrosion performance.

Synthesis of anticorrosive and flame-retardant coating based on turmeric (Curcuma longa) and magnesium hydroxide

The green corrosion inhibitor is used in epoxy coating system by extraction of turmeric in dimethyl formamide (DMF). The major component extracted is curcumin. Three concentrations have been studied for anticorrosive performance i.e., X, 2X and 4X. Among this X based concentration showed the best performance. Magnesium hydroxide Mg(OH)2 has been treated with 3-glycidoxypropyltrimethoxysilane (GPTMS). It was added into coating formulation at three concentrations namely 5%, 7% and 10% (w/w). The best anticorrosive performance has been observed for 5% concentration. As the concentration increases the anticorrosive performance decreases but flame retardancy increases. The 7% Mg(OH)2 concentration has been combine studied with turmeric X concentration. It is observed that combination of extract with Mg(OH)2 gives good anticorrosive performance as well as flame retardant properties. The anticorrosive performance is evaluated by salt spray and electrochemical impedance spectroscopy (EIS) and flame retardancy is evaluated by Limiting oxygen index (LOI) and UL-94 study.

Investigation of the wettability, anticorrosion, and accelerated weathering behaviors of siloxane-modified acrylic resin and functionalized graphene nanocomposite coatings on LY12 aluminum alloy

To expand the applications of graphene which has so far been limited by the expensive nature of single-layer graphene, the effects of varying percentages of low-cost functionalized multilayer graphene nanosheets in siloxane-modified organic coatings were studied. The hydrophobic organic siloxane–acrylic resin was prepared by solution polymerization of acrylic monomers, and the graphene nanosheets were functionalized using fluorosilane. The coatings were sprayed on the LY12 aluminum substrate, and the wettability, anticorrosion, conductive, and accelerated weathering behaviors were comprehensively examined. It is shown that the increasing addition of functionalized graphene nanosheets increases the water contact angle and the surface conductivity. At 5% graphene loading, coating–substrate adhesion remains almost unchanged, while the electrochemical impedance parameters revealed good anticorrosion performance up to 10% loading. The surface measurements and Fourier transform infrared spectroscopy (FTIR) results confirmed the photostabilization ability of graphene loading in acrylic coatings during the accelerated weathering test. Also, the mechanical properties of the coatings were not damaged during the exposure, and pitting corrosion sites were observed only on the 20% graphene-filled coatings after 1000 h of exposure. These integrated analyses of mechanical properties and environmental accelerated tests are beneficial to engineering applications of graphene coatings.

Enhanced corrosion resistance and applicability of Mg/Al-CO32− layered double hydroxide film on Q235 steel substrate

Corrosion is a common occurrence in the practical application of steel, especially in marine environments accompanied by aggressive chlorides. In this paper, in situ grown Mg/Al-CO32− layered double hydroxide (LDH) films were first proposed and directly synthesized on Q235 steel substrate to enhance the corrosion resistance of steel under 3.5 wt% NaCl solution and simulated concrete pore solution with chlorides for potential application in concrete environment. The materials characterization presents that the proposed Mg/Al-CO32− LDH film was successfully prepared and grown on the steel substrate. The electrochemical and morphology results reveal that the steel with Mg/Al-CO32− LDH film has good anticorrosion performance and long-term corrosion protection effect.

Preparation of epoxypropyl functionalized graphene oxide and its anticorrosion properties complexed with epoxy resin

Functionalized graphene oxide (GO)/epoxy resin (EP) composite coating has attracted attention due to its advantages of epoxy resin in acid resistance, anticorrosion and having the characteristics of GO such as good chemical stability and strong electrolyte barrier properties. In this study, epoxypropyl functionalized graphene oxide (EFGO) was synthesized with a new strategy by grafting epichlorohydrin (ECH) onto the surface of GO. EFGO was then cross-linked with EP by diethylenetriamine (DETA) to fabricate EFGO/EP anticorrosive coating. The structure and property of EFGO and EFGO/EP were characterized and evaluated by various methods such as FTIR, Raman, XPS, SEM, and EIS. The results showed that the graft amount of epoxypropyl on GO surface could be effectively increased by using KI-KF catalysis system. The increase of the graft amount further improved the compatibility between EFGO and EP. EFGO/EP had a network structure with EFGO as the “central node”. The “central node” locked the movement of EP chain segment, as improving the thermal stability of EFGO/EP. The EFGO/EP coating fabricated by the EFGO, which grafted larger epoxypropyl, had good anticorrosion performance and adhesion with steel plates, showing a good barrier effect on electrolyte migration. The coating resistance reached up 4.88×108 Ω cm2.

Evaluation and Improvement of the Coupled Effect of High-temperature Corrosion-erosion on Water Wall Tubes

Low-alloy and heat-resistant steel generally shows good anti-corrosion performance. Also unlike CFB boiler, there is little serious erosion happening in furnace of the pulverized coal boiler due to the low particle concentration. But when subjected to the coupled effect of high-temperature corrosion-erosion, serious failures would occur. This study analyzed the reason for eroded failure of water wall tubes of a 660 MW supercritical boiler with pulverized coal combustion, concluding that such failure resulted from the coupled effect of high-temperature corrosion-erosion. Analysis of the failed sample determined that failure was caused by the combination of high-temperature corrosion-erosion and the rate of failure was faster than that occurring solely by erosion. The numerical simulation result also showed that the H2S concentrations of the fault areas are much higher than others which are coincide with the fact. Furthermore, the study proposed the way of improving the situation for the special four-wall tangential firing through numerical simulation.

Probing the Synergy of Blended Lithium Complex Soap and Calcium Sulfonate Towards Good Lubrication and Anti-Corrosion Performance

Thickener plays a significant role on the performance of grease, including rheological property, chemical and thermal stability, colloidal and mechanical stability, and so forth. Here, lithium complex-calcium sulfonate (L/C) greases were synthesized via regulating lithium complex soap and calcium sulfonate in the molar ratio of 1:2, 2:1 and 1:1, along with thickening the polyalphaolefin (PAO40). The physicochemical properties, corrosion resistance and tribological performance were evaluated in detail, with lithium complex grease and calcium sulfonate grease as a comparison. The results show that the as-prepared L/C greases have good corrosion resistance for low-carbon steel due to unique reversed micelles of calcium sulfonate and sealing function. The regulation of lithium complex soap and calcium sulfonate in different molar ratios achieves the considerable adjustability of grease’s physicochemical and tribological properties due to the component/structure of thickener and its sensitivity to base oil. The grease with formulation of L/C = 1:2 gives the best lubrication function depending on not only the thickener’s component and structure, but also the synergistic lubrication of grease-film and tribo-chemical reaction film composed of Fe2O3, FeO(OH), CaO, CaCO3 and LiOH. The schematic diagram of tribological mechanism of the as-prepared grease, a the start of the friction, b the friction after a period of time.

Robust superhydrophobic coatings prepared by cathodic electrophoresis of hydrophobic silica nanoparticles with the cationic resin as the adhesive for corrosion protection

The practical application of superhydrophobic surfaces in corrosion protection often suffers from complicated fabrication processes, requirement for high-cost fluorosilane modification and poor mechanical durability. In order to address above mentioned drawbacks, in this work, robust protective superhydrophobic SiO2 coatings are fabricated on electrically conductive metal surfaces by a single one-step electrophoretic deposition (EPD) technique from EPD bath containing superhydrophobic SiO2 nanoparticles (SH-SiO2 NPs) and resin-based adhesive. The as-prepared superhydrophobic coatings exhibit good anti-corrosion performance in 3.5 wt.% NaCl solution. Furthermore, additional corrosion inhibition is achieved after incorporation of inhibitors into the above superhydrophobic coatings by deposition of inhibitor-loaded SH-SiO2 NPs.

Proposal and Verification of a Novel Superhydrophobic-Conductive Anti-Corrosion Polyaniline-Silica Coating

Abstract There has been a growing interest in stainless steel (SS) corrosion due to massive economic losses. Current efforts are mainly devoted to forming Cr2O3 film or organic coatings on SS surfaces. However, the relevant chromate is a carcinogen and the traditional organic coatings are inefficient for electrochemical corrosion. Here, we prepared a novel superhydrophobic-conductive anti-corrosion polyaniline-silica (PANI-SiO2) coating, the internal conductive polyaniline layer effectively reduces electrochemical corrosion, the external superhydrophobic silica layer obviously reduces chemical corrosion. Compared with 304 stainless steel (304SS), the corrosion potential (Ecorr) of the PANI-SiO2 increases to more than 331 mV (SCE), the corrosion current (Icorr) is reduced by more than one order of magnitude, and the anti-corrosion efficiency reaches 97.51%. Meanwhile, the PANI-SiO2 coating has good long-term anti-corrosion performance for 304SS.

Camphor leaves extract as a neoteric and environment friendly inhibitor for Q235 steel in HCl medium: Combining experimental and theoretical researches

Camphor leaves extract (CLE) as a neoteric and environment friendly inhibitor for Q235 steel in HCl medium was researched via experimental and theoretical researches. In this work, we used green, convenient pure water extraction method to obtain camphor leaves extract. Fourier transform infrared spectroscopy data show that there are many organic molecules with oxygen-containing functional groups in the organic in CLE. Electrochemical experimental data show that CLE is a mixed-type corrosion inhibitor and can exhibit good anti-corrosion performance. The concentration of CLE is 600 mg/L, its corrosion inhibition efficiency is 89.4% at 298 K. Surface morphology analysis (AFM and SEM) vividly shows the corrosion inhibition performance of CLE. The adsorption behavior of CLE onto Q235 steel/solution interface is obey Langmuir single-layer adsorption. Theoretical calculations show that CLE can exhibit good anti-corrosion performance.

Adsorption Behavior of GTMS on AA2024-T3 Aluminum Alloy and the Application on Surface Pretreatment

Basing on the study of adsorption behavior of glycidoxypropyl-trimethoxy-silane (GTMS), pretreatment method of AA2024-T3 aluminum alloy for sol-gel films was optimized. The morphology, composition and corrosion protective performance of alloy coated with the films were investigated by using FE-SEM, EDS, AFM and EIS. The results showed that the Al matrix exhibited better ability to adsorb GTMS molecules than the second phase particles, especially at lower concentration of GTMS. Further, the 5% GTMS films cover the whole surface, but the selective adsorption behaviors still exist. It was concluded that less second phase particles and smoother surface were benefit to the sol-gel films on aluminum alloy. Depending on this conclusion, the pretreatment method for sol-gel films was optimized. The optimized surface condition conducted with 50 g•L-1 sodium hydroxide and ultrasound at 60 oC for 30 s was obtained. These samples coated with the sol-gel films revealed good anti-corrosion performance. The coverage degree of the films was up to 97.95 %.

Preparation and Performance Test of the Super-Hydrophobic Polyurethane Coating Based on Waste Cooking Oil

In order to solve the problem of dust accumulation on the fin surface of a mine air cooler, a method of preparing super-hydrophobic polyurethane (SPU) coating based on waste cooking oil (WCO) was proposed. Firstly, the polyurethane prepolymer was synthesized with WCO as a raw material, and then the polyurethane prepolymer was modified with amino-terminated polydimethylsiloxane (ATP) to obtain SPU emulsion. The chemical structure and thermal stability of SPU were characterized by infrared spectrum and thermogravimetric analysis. A series of nanocomposites were prepared by combining modified silicon carbide (APT-SiC) particles and SPU emulsions. According to the parameters of pull-off strength, contact angle, sliding angle and thermal conductivity, the filler ratio of nanocomposites was optimized. The test results show that when the content of APT-SiC particles is 20 wt %, super-hydrophobic polyurethane coating can be obtained. The coating has good pull- off strength and thermal conductivity, and the contact angle and sliding angle are 161° and 3°, respectively. In addition, the practical application of the super-hydrophobic polyurethane coating was tested by related experiments. The experimental results show that the coating has good self-cleaning, wear resistance and anti-corrosion performance, can meet the requirements of air coolers in special environments, and has great application prospects.

PPA-containing layered double hydroxide (LDH) films for corrosion protection of a magnesium alloy

In this study, Mg alloys coated with four kinds of MgAl-layered double hydroxide (LDH)-based films with and without PPA were fabricated. PPA, as a small-molecule corrosion inhibitor, can be introduced into the LDH interlayer by virtue of in situ growth and anion exchange methods. Comparisons of the anti-corrosion performance of the LDH films were conducted by means of EIS, potentiodynamic polarization and endurance measurements. The introduction of PPA into LDH films provides more effective corrosion protection on a Mg alloy due to the blocking effect of the LDH film and the corrosion inhibition of PPA. Moreover, the different PPA introduction methods show significant differences in surface morphology, impedance behaviour and durability. Herein, the MgAl-PPA LDH film, which is obtained by introducing PPA in the in situ growth process, displays an excellent anti-corrosion ability due to its stable film structure. Although PPA-containing LDH films obtained via the anion-exchange method initially present a relatively good anti-corrosion performance, their susceptible film structure displays their low durability.

Application zinc silicate-potassium silicate coating for anticorrosion of steel bar in autoclaved aerated concrete

For improving the environmental performance of the anticorrosive coatings for steel bar in autoclaved aerated concrete (AAC), zinc silicate powder was added into the potassium silicate solution to prepare the self-curing waterborne coating. In addition to the storage stability and curing time, the mechanical properties of the coatings including the adhesive strength, bonding strength and impact resistance were measured. Moreover, the effect of zinc silicate content on the corrosion resistance was conducted using the potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS). Furthermore, the phase component of AAC from the AAC-coating interface, the chemical composition and micrograph of coatings were investigated. The balance among the storage stability, curing time and mechanical properties of coatings could be achieved while the SiO2/K2O molar ratio was 5.5. The Z-5.5-50 coating had the good anticorrosive performance because of the excellent physical shielding.

Rational design of metallic anti-corrosion coatings based on zinc gluconate@ZIF-8

The unique porous characteristic of metal-organic frameworks (MOFs) has been attracting significant attention for gas storage, catalysis and drug delivery. However, the studies regarding loading inhibitors into MOFs for metallic anti-corrosion applications are scarcely reported. Herein, a strategy based on encapsulating corrosion inhibitors into MOFs matrix has been developed, and their corrosion process and mechanism have been fully studied. Specifically, an environmentally friendly green corrosion inhibitor, zinc gluconate (ZnG), was selected as a metal resource for the preparation of ZIF-8 and then inherently intercalated into the porous ZIF-8. Various characterizations were carried out to confirm that zinc gluconate was successfully loaded into the ZIF-8 matrix. Electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization curves show the evidence that the prepared ZnG@ZIF-8/EP coatings display good metallic anti-corrosion performances. The probably protecting mechanism of ZnG@ZIF/EP coatings for magnesium alloy surface was thoroughly discussed.

Continuous supercritical water oxidation treatment of oil-based drill cuttings using municipal sewage sludge as diluent

Oil-based drill cuttings (OBDC) is a characteristic hazardous waste that is generated in oil and gas exploration. In this study, two typical OBDCs from shale gas fields were treated in a continuous supercritical water oxidation (SCWO) for the first time. Because both heat value and ash content (AC) in the OBDCs were well beyond the capacity of continuous operation, municipal sewage sludge (MSS) was innovatively adapted as the diluent. A mixed sludge with OBDC addition levels of 10%, 20%, and 30% was tested using a novel SCWO reactor. Mean residence times of reactants in different reaction zones were specifically calculated. Results indicated the organic carbon removal efficiency could reach up to 98.44%. Eight detected heavy metals were found to be almost completely removed into solid products, and the concentrations in liquid products were all below the discharge limits. It was also found that the SCWO reactor exhibited good anti-plugging and anti-corrosion performance. The AC in the feedstock was up to 28.58%. To the best of our knowledge, this has, hitherto, not been achieved in a continuous SCWO operation. This study provides a new approach for harmlessly and completely degrading OBDC, and is also helpful for the industrialization of SCWO technology.

Thermal and corrosion properties of V-Nb-Mo-Ta-W and V-Nb-Mo-Ta-W-Cr-B high entropy alloy coatings

High entropy alloys (HEAs) have drawn lots of attentions from researchers and industries because of their outstanding properties, such as high hardness, and good corrosion resistance. Particularly, the refractory high entropy alloy is characterized by its high temperature strength and stable thermal properties. We conducted the magnetron co-sputtering process to grow one V-Nb-Mo-Ta-W and three V-Nb-Mo-Ta-W-Cr-B refractory HEA coatings. The BCC phase of V-Nb-Mo-Ta-W HEA coating was changed into the amorphous-like structures when Cr and B elements were added into the coatings. Oxidation reactions occurred and very complex refractory metal oxides were produced on all HEA coatings when the oxidation was held at 800 °C in air for 1 h. The addition of Cr and B constituents into the V-Nb-Mo-Ta-W coating can provide good oxidation resistance and anti-corrosion performance. The highest hardness of 18.4 ± 0.5 GPa, an excellent corrosion resistance at room temperature, a high hardness of 15.9 ± 1.1 GPa and good thermal stability after 500 °C oxidation test were obtained for the V10.4Nb10.5Mo10.5Ta11.2W10.5Cr16.3B28.6 refractory HEA coating in this study.