Anticorrosion Characteristics Research Articles

Novel anticorrosive coatings based on nanocomposites of epoxy, chitosan, and silver

To improve the resistance to corrosion of epoxy resin for steel in sodium chloride solution, new Chitosan-Ag nano-composite coating was synthesized. FTIR, X-ray Diffraction, Raman and TEM all supported the new nano-characterizations composite. A study using electrochemical impedance spectroscopy (EIS) demonstrated that composite coatings had a corrosion rate that was lower than that of pure epoxy coating. Chitosan-Ag nanocomposite-coated carbon steel demonstrated greater coating resistance (396 kohm cm2) than neat epoxy (124 kohm cm2). Our findings support the concept that chitosan and silver nanoparticles can enhance the epoxy coating's anticorrosion characteristics.

Graphene derivatives reinforced metal matrix nanocomposite coatings: A review

Due to the extraordinary mechanical, thermal, and electrical properties of graphene, graphene oxide (GO), and reduced graphene oxide (rGO), these materials have the potential to become ideal nanofillers in the electrodeposited nanocomposite coatings. This article provides an overview of literature on the improvements of properties associated with graphene, GO, and rGO-reinforced coatings, along with the processing parameters and mechanisms that would lead to these improvements in electrodeposited metal matrix nanocomposite coatings, where those affected the microstructural, mechanical, tribological, and anti-corrosion characteristics of coatings. The challenges associated with the electroplating of nanocomposite coatings are addressed. The results of this survey indicated that adding graphene into the plating bath led to a finer crystalline size in the composite coating due to increasing the potential development of specific crystalline planes and the number of heterogeneous nucleation sites. This consequently caused an improvement in hardness and in tribological properties of the electrodeposited coating. In graphene reinforced metallic composites, the severe adhesive wear mechanism for pure metallic coatings was replaced by abrasive wear and slight adhesive wear, where the formation of a tribolayer at the contact surface increased the wear resistance and decreased friction coefficient. Furthermore, superhydrophobicity and smaller grain size resulted from embedding graphene in the coating. It also provided a smaller cathode/anode surface ratio against localized corrosion, which has been found to be the main anti-corrosion mechanism for graphene/metal coating. Lastly, the study offers a discussion of the areas of research that need further attention to make these high-performance nanocomposite coatings more suitable for industrial applications.

A Versatile Bio-packing Based on Natural Extract from Calotropis procera a Sustainable Alternative for Agriculture and Biofouling Applications

Background and objective: Despite the situation in the north of Minas Gerais being semiarid, this region presents a plant with low water demand, Calotropis procera. This plant has a great potential as an antifungicide supply, although other important characteristics. In this context, this research proposes an extraction of natural material from C. procera to produce a bio-packing for agriculture and anticorrosive applications as a sustainable alternative. This biopacking is eco-friendly, low-cost, widely available, and quickly produced. The antifungicide and anticorrosive activity were evaluated as the control of fruit ripening based on in vivo tests. Materials and methods: This research is based on the production of bio-packing based on natural extracts from C. procera seeds for agricultural and anticorrosive applications. The material was characterized by Fourier transform infrared (FTIR), nuclear magnetic resonance (NMR) and surface contact angle. In addition, in vitro and in vivo biological experiments were performed to analyze the antifungal activity and control of fruit ripening. Moreover, the anticorrosive property was also analysed. Results: The results indicated the presence of proteins in the composition of the product based on natural extract, which may contribute to the antifungal and anticorrosive characteristics. Furthermore, the natural extract demonstrated anticorrosive protection in simulated seawater. The in vivo analysis of bananas showed that the extract concentration of 50 μL mL-1 presented the best results, controlling the fruit ripening and protecting against diseases. Conclusion: Thus, for the first time, these products extracted from C. procera seeds presented a great future for applications as a versatile action for agriculture and anticorrosive applications.

Influence of Electrostatic Field on Mixed Aqueous Solution of Calcium and Ferrous Ions: Insights from Molecular Dynamics Simulations

In order to investigate the anti-scaling and anti-corrosion characteristics of an electrostatic anti-fouling system in the application process, the influence of an electrostatic field (EF) on the structure and dynamics of hydrated Ca2+ and hydrated Fe2+ in a mixed aqueous system was studied through the calculation and analysis of the radial distribution function (RDF), self-diffusion coefficients, viscosity, and hydrogen bond structure by using molecular dynamics simulation. The study results show that the EF can decrease the radius of the first water shell of hydrated Ca2+ but increase that of Fe2+, which will reduce the possibility of forming calcite. The EF can make water molecules and Fe2+ more active, which can hinder iron release and thus decrease iron corrosion products. In addition, the EF can enhance the hydrogen structure of water molecules in the aqueous solution.

The Mechanism of Anticorrosion Performance and Mechanical Property Differences between Seawater Sea-Sand and Freshwater River-Sand Ultra-High-Performance Polymer Cement Mortar (UHPC).

There are abundant sea-sand resources on the earth. Traditional sea-sand concrete faced various problems relating to insufficient anticorrosion ability. In this paper, artificial seawater, sea sand, industrial waste, steel fiber, and polycarboxylate superplasticizer were used to prepare ultra-high-performance polymer cement mortar (SSUHPC). At the same time, freshwater river-sand ultra-high-performance polymer cement mortar (FRUHPC) with the same mixing ratio was prepared for comparative study. The compressive strength of SSUHPC reached 162.1 MPa, while the that of FRUHPC reached 173.3 MPa, which was slightly higher. Meanwhile, SSUHPC showed excellent anticorrosion characteristics in terms of carbonization, frost resistance and chloride resistance, and especially for sulfate resistance. The composition of SSUHPC was separated into three parts: mortar, pore and steel fiber, and the performance difference mechanisms of SSUHPC and FRUHPC were investigated by X-ray computed tomography (X-CT), mercury intrusion porosimetry (MIP), scanning electron microscopy (SEM), and X-ray diffraction (XRD). The hydration degree of mortar in SSUHPC was higher, with higher content of CSH and CH, and its better optimized gel pore characteristics gave SSUHPC better corrosion resistance. The mechanical properties of SSUHPC were slightly poor due to the uneven dispersion of steel fibers and air pores, with an- air pore porosity of 1.52% (above 200 μm) that was twice that of FRUHPC (0.6%). In this paper, the mechanics and anticorrosion performance of ultra-high-performance polymer cement mortar prepared with seawater sea sand were comprehensively evaluated, and the mechanism of performance difference between SSUHPC and FRUHPC was revealed, conducive to the targeted improvement of sea sand concrete.

Development of anti-corrosive novel nickel-graphene oxide-polypyrrole composite coatings on mild steel employing electrodeposition technique

Composite coatings based on nickel have recently become popular in the automotive and aerospace industries owing to their corrosion-resistant qualities. However, as many cases have shown, this coating is ineffective in chloride-containing environments. As remediation, a graphene oxide/conducting polymer (Polypyrrole) composite with nickel has been proposed as an effective corrosion protective layer for bare mild steel. Furthermore, electrodeposition is one of the popular methods for coating metals with anti-corrosion coatings. A simple, cost-effective, and environmentally friendly electrodeposition process has been employed for the deposition of graphene oxide/polypyrrole composite with nickel (Ni-GO-PPy) on mild steel. XRD, EDAX, FE-SEM, and FT-ATR were used to analyze this coating extensively. A coated mild steel sample was evaluated in a 3.5% NaCl solution utilizing the Potentiodynamic polarization ,electrochemical impedance spectroscopy and weight loss immersion test to determine the coatings' anti-corrosion characteristics. In all of the experiments, the Ni-GO-PPy coating outperformed bare nickel and Ni–GO coatings in terms of anti-corrosion capabilities. As a result of this research, a practical and scalable technique for using Ni-GO-PPy composite coating to protect mild steel surfaces against corrosion has been demonstrated.

Experimental and In-Silico Computational Modeling of Cerium Oxide Nanoparticles Functionalized by Gelatin as an Eco-Friendly Anti-Corrosion Barrier on X60 Steel Alloys in Acidic Environments.

An eco-friendly and a facile route successfully prepared novel cerium oxide nanoparticles functionalized by gelatin. The introduced CeO2@gelatin was investigated in terms of FE-SEM, EDX, TEM, chemical mapping, FT-IR, and (TGA) thermal analyses. These characterization tools indicate the successful synthesis of a material having CeO2 and gelatin as a composite material. The prepared composite CeO2@gelatin was used as an environment-friendly coated film or X60 steel alloys in acidizing oil well medium. Moreover, the effect of CeO2 percent on film composition was investigated. LPR corrosion rate, Eocp-time, EIS, and PDP tools determined the corrosion protection capacity. The CeO2@gelatin composite exhibited high protection capacity compared to pure gelatin; in particular, 5.0% CeO2@gelatin coating film shows the highest protection capacity (98.2%), with long-term anti-corrosive features. The % CeO2@gelatin-coated films formed the protective adsorbed layer on the steel interface by developing a strong bond among nitrogen atoms in the CeO2@gelatin film and the electrode interface. Surface morphology using FESEM measurements confirmed the high efficiency of the fabricated CeO2@gelatin composite on the protection X60 steel alloys. DFT calculations and MC simulations were explored to study the relations between the protection action and the molecular construction of the coated systems, which were in good alignment with the empirical findings.

LASER CLADDING OF COLMONOY 6 PARTICLES ON INCONEL 625 SUBSTRATE: MICROSTRUCTURE AND CORROSION RESISTANCE

Inconel 625 (IN 625) is a widely recognized nickel-based superalloy due to its high tensile strength, better fabricability, capability to prevent crack formation, acceptable corrosion resistance, etc. However, during the long-term usage, the formed oxide layers are converted into dichromates which reduce the anti-corrosion behavior. This study attempts to improve the anti-corrosion characteristics of IN 625 by cladding it with Colmonoy 6 particles. Further, the corroded morphology, microstructure, hardness and roughness were analyzed. Results showed that the cladded specimens are rich in dendritic and interdendritic areas. These areas are reported to contain rich carbides and borides of Cr that are formed after cladding. These precipitates paved the way for improving the hardness of the Colmonoy-6-cladded layer (7.54 GPa) when compared with the base material (4.49 GPa). A strong and continuous passive film was reported on the cladded samples during the corrosion test which protects the cladded layer. Further, EIS study also reported that the Colmonoy-6-cladded specimens experience higher polarization resistance values due to the stable passive film and lower [Formula: see text] values from the surface roughness measurements. Among the base and cladded samples, the 27-h cladded sample provides better corrosion resistance with greater [Formula: see text] (142,940). In addition, this sample has the minimum roughness ([Formula: see text]m) value than the other samples.

Effects of graphene oxide and current density on structure and corrosion properties of nanocrystalline nickel coating fabricated by electrodeposition

Protective coatings with superior corrosion resistance and enhanced mechanical properties are still greatly required when applied in challenging environments. In this paper, nickel-graphene oxide nanocrystalline coatings with uniform structure have been fabricated by co-electrodeposition technique. Effects of graphene oxide (GO) in plating solution and applied current density on structural, composition, crystallite size and corrosion-resistant properties of electrodeposited Ni-GO nanocrystalline coatings were compared and investigated systematically. The deposited coatings have a compact, crack-free, silver-gray appearance with lower surface roughness, exhibiting colonies-like morphology. The presence and uniform distribution of graphene oxide on the surface as well as inside nickel coating were confirmed. The crystallite size and crystal plane orientation have no significant alteration in the presence of graphene oxide. The preferred orientation of (200) crystal plane of pure Ni is changed to low energy (111) plane for Ni-GO composites. The average roughness Ra of Ni-GO is 3–5 nm. Ni-GO coating contains 2.6–3.9 wt% GO, 95.5–96.9 wt% Ni and some oxygen. With the increase of GO, the corrosion resistance first enhanced to a maximum at 0.2 g L−1 GO. When GO exceeds a certain value, agglomeration occurred, causing uneven dispersion of GO and heterogeneous coarse surfaces. The anti-corrosion capability was enhanced by the incorporation of GO due to the grain refinement and the uniform dispersion of impermeable GO. Current density could change the structure and anti-corrosive features of Ni-GO coating. The Ni-GO nanocrystalline coating possesses enhanced performance, which has a promising application prospect in harsh environments.

Exploration of the effect of Zn-MgO-UPP coating on hardness, corrosion resistance and microstructure properties of mild steel

This paper investigated the effect of unripe plantain peel (UPP) nanoparticles reinforced Zn-MgO composite coating on the hardness, anti-corrosion and microstructure properties of mild steel. The anti-corrosion characteristics of the coatings were examined using the potentiodynamic polarization method, employing 3.65 % NaCl solution as the test medium. The hardness of the coatings was studied employing the Brinell hardness technique, while the microstructure characteristics were examined using XRD and SEM/EDS. The results of the study revealed that the as-received mild steel sample exhibited the corrosion rate and hardness value of 8.6272 mm year-1 and 136.8 kgf mm-2, respectively, while the Zn-MgO coated mild steel sample exhibited a corrosion rate and hardness value of 242.5 kgf mm-2 and 3.6362 mm year-1, respectively. The optimal performing Zn-MgO-UPP coated mild steel sample (sample coated with 20 g L-1 of MgO and 6 g L-1 of UPP) exhibited a corrosion rate and hardness value of 0.8317 mm year-1 and 245.8 kgf mm-2, respectively. The corrosion rate and hardness value of the Zn-20MgO-6UPP coated mild steel sample indicated that the UPP nanoparticles further improved the passivating and strengthening ability of Zn-MgO coating. Moreover, the XRD profile of the coatings possessed high intensities, which indi­cat­ed that the coatings exhibit microstructural and chemical homogeneity, high stability and good texture. It was observed on the SEM micrographs that the Zn-MgO-UPP coating exhi­bited a more refined microstructure compared to the Zn-MgO coating, indicating the grain refining tendency of the UPP nanoparticles. The EDS further indicated the presence of essential and dispersion strengthening elements in the coatings.

MoO42−-doped oxidative polymerized pyrrole-graphene oxide core-shell structure synthesis and application for dual-barrier & active functional epoxy-coating construction

Sodium molybdate (Na2MoO4) doped graphene oxide/polypyrrole nanocomposite (GO-PPy + Na2MoO4) was synthesized and considered as a multi-functional corrosion inhibitor container to be embedded into the epoxy coating. To ensure the decoration of GO surface by PPy nanoparticles and doping of molybdate ions into the GO-PPy structure, several analyses such as FT-IR, Raman, ICP-OES, zeta potential, FE-SEM/EDS, and TEM were used. The active-barrier anti-corrosion features of GO-PPy and GO-PPy + Na2MoO4 in 3.5 wt% NaCl solution were screened by EIS, salt spray, pull-off, and cathodic disbanding tests. Potentiodynamic polarization analyses showed 77% inhibition efficiency in the solution containing GO+PPy + Na2MoO4 compared to the blank solution. The GO-PPy + Na2MoO4 reinforced epoxy coating exhibited the highest impedance (log ׀Z׀10 mHz = 10.58 Ω·cm2, after 63 days) and the lowest delamination values (3.58%, after 63 days) in comparison with the pure epoxy coating (EP) (log ׀Z׀10 mHz = 6.1 Ω·cm2 and delamination value = 48.75%, after 63 days). The interaction of the NH bonds in the PPy chain with the oxide layer, and the formation of molybdate-containing compounds resulted in a considerable enhancement of the epoxy coating adhesion to the metal surface in the presence of GO-PPy + Na2MoO4.

Volume fraction effect of stainless steel on microstructure, interface, corrosion and wear behavior of stainless steel / aluminum bimetal composites

304 stainless steel (SS)/A356 aluminum bimetal composites were manufactured by vacuum-assisted melt infiltration casting successfully. SS chips with different volume fractions of 35%, 50%, 60%, and 65% were used in a composite structure. Low-cost, environmentally friendly production was achieved by using chips as reinforcing material. Dry sliding ball-on-disc tests were performed against Al2O3 ball under a load of 10 N. Potentiodynamic polarization analysis was carried out in 3.5% NaCl solution. θ (Fe4Al13) and η (Fe2Al5) phases developed at the SS/Al interfaces. Abrasive and adhesive wear predominated worn surfaces, whereas galvanic and pitting corrosion mechanisms originated during potentiodynamic polarization tests. Lower volume fractions of SS chips resulted in microploughing, while their higher amounts caused microcutting during sliding. Moreover, the samples containing 60% and 65% SS failed in the corrosion tests due to the lack of passivation. The most suitable SS ratio was determined to be 50%, considering microstructural, interfacial, tribological, and anti-corrosion features of SS/Al bimetal composites.

Four novel imidazolium-derived ionic liquids: Synthesis and anti-corrosion characteristics

This paper describes the corrosion inhibiting action of four new imidazolium-derived ionic liquids (ILs). Elements analysis, Infrared, TGA, 1H–13C NMR, XRD and HSQC-NMR were used to confirm the molecular formula of ILs. The corrosion suppressive effectiveness was calculated using loss of mass and electrochemical experiments and ranged from 53 to 96%. Their adsorption on a steel substrate was precisely characterized using the Langmuir isotherm. Gibbs free energies vary from − 35.24 kJ mol−1 to − 41.82 kJ mol−1, indicating that ILs are adsorbing via physi-chemisorption scenario. SEM/EDX and FTIR were used to validate the process of adsorption of ionic liquids.

Performance Evaluation of hi-k Lung-inspired 3D-printed Polymer Heat Exchangers

Polymer heat exchangers are attractive thermal management solutions due to their low-cost, lightweight, antifouling, and anti-corrosion characteristics. They, however, demonstrate poor thermal characteristics mainly due to the low thermal conductivities of typical polymers. Additive manufacturing of high thermal conductivity polymer heat exchangers utilizing complex heat transfer topologies could potentially address the issue. In this study, thermal performances of 3D-printed polymer heat exchangers with intricate internal geometries including a lung-inspired design at low-to-high thermal conductivities are experimentally and numerically examined. It was found the effective thermal conductivity of a 3D-printed polymer heat exchanger is close to the through-plane thermal conductivity. It was also identified that through-plane leakage in thin 3D-printed polymer walls is a major challenge associated with 3D-printed polymer heat exchangers. The issue was remedied by in-situ infusion of an epoxy layer during the 3D-printing and a post-curing process. Experiments conducted at various thermo-hydraulic conditions showed that the high thermal conductivity lung-inspired polymer heat exchanger offers high thermal duties at reduced pressure drop penalties and exceptionally high effectiveness of 70–80% that is comparable to that of metal-based heat exchangers. At an air Reynolds number of 1200, the volume-based power density of the high thermal conductivity lung-inspired design is 522 kW/m3, which is a 101% improvement compared with a typical plate-and-frame design. This study concludes that the thermal performance of a polymer heat exchanger strongly depends on both material (i.e., thermal conductivity) and architecture (i.e., an optimum design with a minimal thermal resistance between hot and cold sides). Insights gained from this study could offer new pathways for designing innovative 3D-printed polymer heat exchanger technologies with unprecedented heat transfer rates at reduced pressure drop penalties for lightweight, antifouling, and/or anti-corrosion applications.

Anti-corrosion characteristics of FeCO3 and Fe Ca Mg CO3 scales on carbon steel in high-PT CO2 environments

• Anti-corrosion capabilities of FeCO 3 and Fe x Ca y Mg z CO 3 scales were compared. • FIB and µCT were applied to reveal the pore characteristics within the scales. • General corrosion rate is closely related to the available active surface areas. • FeCO 3 scales provide superior anti-corrosion protection than Fe x Ca y Mg z CO 3 scales. Corrosion products formed on carbon steel can be considered as naturally occurring anti-corrosion scales. However, relationships between porosity and anti-corrosion characteristics of such scales remain poorly understood. In this study, characterisation data derived from Focus ion beam (FIB) and X-ray micro-computed tomography (μCT) techniques, combined with image processing algorithms, were applied to reveal the porosity, pore connectivity and pore size distribution within FeCO 3 and Fe x Ca y Mg z CO 3 (where x + y + z = 1) scales on a X65 carbon steel substrate. The formation kinetics, chemistry and anti-corrosion capabilities of both scales were also systematically evaluated by Scanning electron microscopy (SEM) coupled with Energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), profilometry and electrochemical measurements. The results demonstrate that FeCO 3 scales can reduce the availability of active surface areas more efficiently with their lower porosity on the steel surface, providing superior anti-corrosion performance than Fe x Ca y Mg z CO 3 scales. This study elucidates the effects of ubiquitous cations on the formation and relative protectiveness of corrosion product scales, as well as their effectiveness to protect against corrosion.

Fluorocarbon Production Residue in Composite Coating Used for Protecting Heat-and-Power Equipment from Damage

Most often breakage in heat-and-power facilities is caused by decomposition of heating elements while in process. The reason of it is a thick layer of boiler scale on their surface caused by hardness salts and ferric carbonates in industrial water, as well as by roughness of the surface of the heater. The quality of the surface is improved by polishing and covering it with a layer of nickel. The above-mentioned processes could be replaced by covering the surface with a composite electrochemical coating (CEC nickel-fluorocarbon) using fluorocarbon production residue which contains a mixture of fluorocarbon and carbon black. Estimate of the parameters of the process of getting CEC nickel-CFx showed that nickel current output does not depend on presence of a dispersion phase (CFx) in conditions of high current density. Throwing power is even, so that it is possible to get uniform nickel coatings and CEC nickel-CFx. It was stated that the physical characteristics, as well as anti-scaling and anti-corrosion characteristics of CEC nickel-CFx are higher than those of nickel coating. CEC nickel-CFx is recommended for using in heat-and-power equipment.

Particle-Size-Dependent Anticorrosion Performance of the Si3N4-Nanoparticle-Incorporated Electroless Ni-P Coating

Electroless Nickel–Phosphorus (Ni-P) coating is recognized mostly for its outstanding corrosion and wear-resistant behavior. The intrinsic corrosion and wear-resistant properties of Ni-P-based coating could be further upgraded by incorporating appropriate second-phase additive particles into the coating matrix. However, such properties of the Ni-P-based coating greatly rely on the surface and microstructural evolution arising with the co-deposition of the additive particles. In this study, submicron Si3N4 (average size ~200 nm) and nano Si3N4 (average size ~20 nm) particles were incorporated while depositing a Ni-P alloy in a low-carbon steel substrate to develop the Ni-P-Si3N4 composites through the electroless coating method. The 20 nm Si3N4-incorporated composite coating constituted fewer defects such as cavities and micropores on the surface, but such defects significantly appeared on the surface of the composite after the incorporation of 200 nm Si3N4 nanoparticles. Subsequently, the composite Ni-P-Si3N4, developed with the co-deposition of 20 nm nanoparticles, is enriched with enhanced anticorrosion characteristics compared with the composite developed with 200 nm nanoparticles. The enhancement of anticorrosion behavior was attributed mainly to the Si3N4 nanoparticles that covered the substantial volume of the coating and led to inhibit the formation of corrosion active sites such as defects and metallic Ni phase.

FEATURES OF THE FORMATION OF THE COATING STRUCTURE ON TITANIUM-BASED ALLOYS

Previously shown that coatings formed on titanium by plasma electrolytic oxidation (PEO) in an electrolyte with zirconium sulfate Zr(SO4)2 consisted of ZrO2 and TiO2 oxides, their surface layer is enriched with zirconium, they have good protective properties in chlorine-containing media. The resulting layers have a fairly regular distribution of relatively small pores, with a diameter of about 1 μm or less, on the surface. The composition and structure of PEO layers depend on both the composition of the electrolyte and the modes of formation. It is of scientific and practical interest to elucidate the effect of the conditions for the formation of coatings with ZrO2 on titanium and its alloys on their anticorrosive properties in chlorine-containing media. Samples for research were formed under anodic (unipolar) conditions at the same current density and different formation times. The samples were formed in modes with current density 0.08 A/cm2 and processing time (minutes) − 8.5; 9.5; 10; 11; 12; 13; 14; 15; 20; 30; 40; 60. The duration of treatment was chosen as to maximally repeat the anticorrosive characteristics obtained in the previous case. The work uses modern research methods, including electron microscopy, presents the results of further study of ZrO2 + TiO2 / Ti systems formed in an electrolyte with zirconium sulfate Zr(SO4)2. It has been established that coatings are formed on titanium and its alloys in an electrolyte with zirconium sulfate under galvanostatic conditions of the PEO process at i = 0.08 A / cm2 during a processing time of 11-15 min. There is a correlation between the stages of galvanostatic formation of coatings and their anticorrosive properties.

Steel protection in acidified 3.5% NaCl by novel hybrid composite of CoCrO3/polyaniline: Chemical fabrication, physicochemical properties, and corrosion inhibition performance

Perovskite-type oxide (CoCrO3) was used as a core content of the material to synthesize oxide/PANI nanocomposite. The introduced composite was synthesized by two steps; oxide formation followed by in situ polymerization to cover the oxide surface by the conductive polyaniline polymer (PANI). The as-prepared oxide/PANI material was studied in terms of FE-SEM, TEM, XRD, FT-IR, BET, and XPS analyses. These characterization tools indicate the successful synthesis of a material having oxide and PANI as a composite material. The corrosion protection performance of an oxide/PANI material in a comparison with individual PANI was tested for carbon steel 1018 (CS-1018) in acidified 3.5% NaCl solution. The corrosion protection capacity was determined by LPR corrosion rate, Eocp-time, EIS, and PDP tools. The CoCrO3/PANI composite exhibited high protection capacity around 98.8% at the concentration of 150 mg/L and acted as a mixed type inhibitor i.e., inhibited both anodic and cathodic reactions. The adsorption behavior obeyed the Langmuir isotherm model with competitive physical and chemical adsorption. Surface morphology using FESEM/EDX measurements confirmed the high efficiency of the fabricated CoCrO3/PANI composite on the protection CS-1018 in acidified brine. It was observed that transition metal oxide (CoCrO3) nanoparticles reinforce the barrier and anticorrosive characteristics of PANI. The attained findings indicate that the prepared stabilized system (CoCrO3/PANI composite) is an outstanding inhibitor for CS-1018 corrosion in acidic solutions containing chloride.

Tuning of WO3 nanoparticles integration into Fe–Zn intermetallic layers of hot-dip zinc coating to control corrosion

The paper reports about an in-depth analysis on the dissolution study of ɳ, ζ and δ phases of composite zinc coating developed by integrating WO3 nanoparticles, and assessment of their anti-corrosion characteristics. The composite coating with WO3 nanoparticles effectively integrated into the ɳ phase than the mixed ζ &δ phases or γ phase offers the best corrosion protection characteristics. The superior anti-corrosion performance of composite zinc coating with distinct amount of nanoparticles integration into the ɳ phase than the other intermetallic phases is due to the formation of compact and crack free Fe–Zn intermetallic layer with strong W–Zn bonds. The work is proposed as a cost-effective and simple method for the evaluation of high-temperature coatings, where the performance is influenced by the formation and stability of interior intermetallics.