Water Corrosion Resistance Research Articles

Surface engineering of Q235 carbon steel through a superamphiphobic composite coating enabling robust corrosion resistance and antifouling

Developing an efficient strategy to ensure the resistance of corrosion on Q235 carbon steel from liquid-based contaminants is a challenging work. Although superhydrophobic and superamphiphobic coatings have been fabricated, their susceptibility to oily liquids and poor mechanical robustness still limits their ability to tackle corrosion. Herein, the synthesis and fabrication of a new robust superamphiphobic nanocomposite was presented by combining the reinforcement properties of silicon oxide and the mechanical and thermal stability of zinc oxide into a polytetrafluoroethylene polymer matrix via a colloidal homogenization route. The newly developed composite exhibits a hierarchical bumpy structure, leading to excellent water and oil repellent properties. Importantly, the composite possesses a robust mechanical stability to sandpaper abrasion over a distance of 2000 cm under a 100 g load and a stronger adhesion to substrate. As a result, Q235 coated with this composite exhibits an excellent corrosion resistance in saline water for up to 120 days, and a good self-cleaning and antifouling abilities in most corrosive media. This finding reveals a new pathway for resisting the corrosion attacks on Q235 carbon steel and thereby rendering this strategy with practical application in industrial and marine settings.

Study on the construction of durable superhydrophobic coatings using simple spray coating method and their underwater drag reduction performance

Superhydrophobic surfaces have significant applications in industrial and chemical fields. However, their current mechanical stability and underwater durability are insufficient, limiting their widespread application. This study successfully developed a durable superhydrophobic coating suitable for various substrates using a simple one-step spraying technique. By thoroughly investigating the effects of SiO2 concentration and curing temperature on the coating's wettability, underwater durability and mechanical stability, the preparation process was optimized. The prepared superhydrophobic coating achieved a contact angle (CA) of 159.6° and a sliding angle (SA) of less than 1°. In tests of underwater immersion, sandpaper abrasion, repeated water impact, corrosion resistance and ultraviolet (UV) resistance, the coating demonstrated excellent underwater durability, mechanical stability, chemical stability and UV stability. Furthermore, when applied to the steel sphere, the superhydrophobic coating exhibited significant drag reduction effects underwater, reducing the drag coefficient by approximately an order of magnitude and achieving a drag reduction efficiency of 79.1 %. Numerical simulations using STAR-CCM+ showed that the streamlined cavity formed by the superhydrophobic coating effectively suppressed fluid separation, reduced pressure-induced drag, and allowed the superhydrophobic steel sphere to attain a higher terminal velocity. Therefore, the superhydrophobic coating developed in this study has tremendous application potential in underwater drag reduction and is expected to provide effective solutions for energy-saving and drag reduction in fields such as maritime navigation.

Effect of Co-Sputtered Copper and Titanium Oxide Coatings on Bacterial Resistance and Cytocompatibility of Osteoblast Cells.

One of the primary risk factors for implant failure is thought to be implant-related infections during the early healing phase. Developing coatings with cell stimulatory behaviour and bacterial adhesion control is still difficult for bone implants. This study proposes an approach for one-step deposition of biocompatible and antimicrobial Cu-doped TiO2 coatings via glow-discharge sputtering of a mosaic target. During the deposition, the bias of the Ti6Al4V substrates was changed. Structure examination, phase analysis, and surface morphology were carried out using X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM), atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS). The hardness values and hydrophilic and corrosion performance were also evaluated together with cytocompatible and antibacterial examinations against E. coli and S. aureus. The results show great chemical and phase control of the bias identifying rutile, anatase, CuO, or ternary oxide phases. It was found that by increasing the substrate bias from 0 to -50 V the Cu content increased from 15.3 up to 20.7 at% while at a high bias of -100 V, the copper content reduced to 3 at%. Simultaneously, apart from the Cu2+ state, Cu1+ is also found in the biased samples. Compared with the bare alloy, the hardness, the water contact angle and corrosion resistance of the biased coatings increased. According to an assessment of in vitro cytocompatibility, all coatings were found to be nontoxic to MG-63 osteoblast cells over the time studied. Copper release and cell-surface interactions generated an antibacterial effect against E. coli and S. aureus strains. The -50 V biased coating combined the most successful results in inhibiting bacterial growth and eliciting the proper responses from osteoblastic cells because of its phase composition, electrochemical stability, hydrophilicity, improved substrate adhesion, and surface roughness. Using this novel surface modification approach, we achieved multifunctionality through controlled copper content and oxide phase composition in the sputtered films.

Superhydrophobic surface preparation and tribological properties of Ti-1023 alloy with parallel groove

Superhydrophobic surfaces are increasingly vital in materials science due to their exceptional properties such as water repellency, self-cleaning, and corrosion resistance. However, fabricating these surfaces on metal substrates poses significant challenges, including the need for precise control over micro- and nano-structures and ensuring their durability under mechanical and environmental stresses. This study introduces a novel fabrication method for superhydrophobic surfaces on Ti-1023 alloy utilizing nanosecond laser ablation followed by chemical modification with perfluorodecyltriethoxysilane. This technique allows precise microstructural adjustments and enhanced durability. Our findings demonstrate that a groove spacing (GS) of 100 μm optimizes the water contact angle to 162.8° and the water sliding angle to 7.8°. Meanwhile, a GS of 200 μm minimizes the coefficient of friction to 0.176 under starved-water lubrication conditions. These advancements demonstrate the method’s effectiveness in reducing wear and friction, and highlight its potential in aerospace and other high-performance industries.

МОДИФИЦИРОВАНИЕ СВОЙСТВ ГИДРОТЕХНИЧЕСКИХ БЕТОНОВ ДОБАВКАМИ НА ОСНОВЕ ВЫСОКОМОЛЕКУЛЯРНЫХ СОЕДИНЕНИЙ

Ensuring high water resistance, frost resistance and corrosion resistance of hydraulic structures is achieved by creating concrete with a dense structure that can absorb aggressive influences. This is possible by modifying the structure of concrete with polymer additives of new generation. The introduction of polymer additives has a plasticizing effect and contributes to the preservation of technological properties of the concrete mixture, modifies the pore structure of concrete and influences the formation of cement stone strength. The paper presents the results of research on the effect of polymer additive based on polyvinylpyrrolidone on the basic properties of Portland cement binder. It was found that the compressive strength at the age of 2 days increases by 7% at the content of polymer additive in the amount of 0.8%. Also, in-troduction of polymer additive increases the compressive strength at the age of 28 days at its content of 0.6 and 0.8% by 22 and 27%, respectively. The effect of polymer modifier on the formation of the initial structure, manifested in the increase in the time of the beginning and accel-eration of the end of setting has been established. The kinetics of heat release of cement dough in the presence of polymeric modifier in the amount of 0.6 % has been studied. The data on the phase composition of cement stone in the presence of polymer modifier are given. It is established by means of electron microscopic analysis that the introduction of polymeric admixture promotes modification of cement stone microstructure with formation of more dense homogeneous structure. The given research results are taken into account in the development of concrete compositions with a set of specified properties required for the construction of hydraulic structures.

Predictive Analysis of Water Wettability and Corrosion Resistance of Secondary AlSi10MnMg(Fe) Alloy Manufactured by Vacuum-Assisted High Pressure Die Casting

Predictive Analysis of Water Wettability and Corrosion Resistance of Secondary AlSi10MnMg(Fe) Alloy Manufactured by Vacuum-Assisted High Pressure Die Casting

ULTRASONIC-ASSISTED ELECTRODEPOSITION OF CoMo/Al2O3 COMPOSITE COATING ON THE SURFACE OF STEEL AND ITS CORROSION RESISTANCE IN SIMULATED SEWAGE WATER

The ultrasonic is applied during the electrodeposition process of CoMo/Al2O3 composite coating on 10# steel to enhance its corrosion resistance in simulated sewage water. The influence of ultrasonic power on the thickness, roughness, chemical composition, surface morphology, and corrosion resistance of the composite coating is investigated. In an aqueous solution, a co-deposition of cobalt and molybdenum can be induced to form CoMo alloy coating. The Al2O3 nanoparticles are incorporated into CoMo alloy to form CoMo/Al2O3 composite coating. When the ultrasonic power increases from 0[Formula: see text]W to 100 W, the electrodeposition rate of the composite coating increases from 63.25[Formula: see text]mg/h to 153.73[Formula: see text]mg/h, and the thickness of the composite coating also increases from 15.6[Formula: see text][Formula: see text]m to 28.1[Formula: see text][Formula: see text]m. The surface roughness of composite coating electrodeposited without ultrasonic is about 0.436[Formula: see text][Formula: see text]m. The CoMo/Al2O3 composite coating electrodeposited at 100[Formula: see text]W ultrasonic power exhibits the smallest surface roughness of 0.193[Formula: see text][Formula: see text]m and presents a denser surface morphology composed of 74.4% Co, 10.3% Mo, and 15.3% Al, resulting in better corrosion resistance with the smallest corrosion current density of only 9.7[Formula: see text][Formula: see text]A/cm2. However, when the ultrasonic power is 150[Formula: see text]W, the intense hydrogen evolution on the surface of the cathode reduces the density of the coating surface, which leads to the deterioration of corrosion resistance.

Corrosion resistance of 9–12Cr ODS steels in pressurized water for fusion application

The blanket design of Chinese fusion engineering test reactor (CFETR) may utilize pressurized water as coolant. The fusion structural materials will endure high temperature, high pressure and result in corrosion in the pressurized water. It is necessary to verify corrosion resistance of the materials. In the present study, three kinds of advanced fusion structural materials with excellent mechanical properties and neutron irradiation resistance, i.e., 9Cr-ODS steel, 9CrODS-Al steel, and 12CrODS-Al steel were immersed in pressurized water at 325 °C under the pressure of 15.5 MPa up to 859 h. Room-temperature tensile properties were investigated for the materials before and after corrosion. The oxidation layers of the steels were analyzed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The ODS steels have good corrosion resistance in the pressurized water, especially the 9CrODS-Al and 12CrODS-Al steels. The outer oxide layer is identified as Fe2O3 for all the steels. The inner layer is mainly FeCr2O4 for the 9CrODS steel, and Fe(Al,Cr)2O4 for the ODS steels with Al element which better protect the steels from further corrosion. The relevant properties data can provide reference for the blanket materials choice of CFETR and the future fusion reactors.

Effect of a Crystalline Admixture on the Permeability Properties of Concrete and the Resistance to Corrosion of Embedded Steel

Reinforced concrete structure durability hinges on concrete permeability, which relies on the characteristics of the inner porous network. Harmful ions and gases can accelerate steel corrosion. Permeability-reducing admixtures (PRA), including crystalline admixtures (CA), are commonly used to mitigate this. This study examines a commercial CA’s impact on durability-related aspects in concrete specimens. Two concrete mixtures with matching proportions were prepared: a reference mix and another mix with a commercial crystalline admixture. Several properties were studied, such as compressive strength, density, porosity, electrical resistivity, water absorption capacity, chloride diffusion, air permeability, and corrosion resistance. The studied admixture in concrete yields several positive outcomes such as a slight reduction in mixing water, a potential 6% increase in concrete’s compressive strength and the development of a denser and less permeable structure with 3% lower porosity and water absorption than the reference mix. Electrical resistivity improves by 10%. Unidirectional chloride diffusion tests show no differences. Air permeability decreases by from 36% to 55%, and the water absorption rate diminishes by 23%. The admixture potentially reduces the scatter in corrosion initiation periods for steel reinforcements, delaying corrosion onset by around 60 days, although more extensive experiments are needed for definitive conclusions.

Fabricating hydrophobic silica fume to improve mechanical strength and anti-corrosion of integral hydrophobic cement mortar and its carbon emission assessment

Integral hydrophobic concrete possesses superior waterproof performance and can prevent internal concrete and steel bar from erosive ions attacking in marine environment. However, the low mechanical strength limits its application. Silica fume (SF) and stearic acid (SA) were used to prepare hydrophobic SF by ball milling. Further, the prepared hydrophobic SF was added to cement mortar to fabricate integral hydrophobic cement mortar. Effects of hydrophobic SF on compressive strength, water resistance and anti-corrosion performance of integral hydrophobic cement mortar were investigated. Besides, the cement hydration products and morphology were analyzed after the addition of hydrophobic SF. The results showed the compressive strength of integral hydrophobic cement mortar reached 48.3 MPa. The contact angle of integral hydrophobic cement mortar surface arrived 151.5–152.7°. The capillary absorption coefficient also reduced by 93.06 %–93.67 % compared with the control group. Electrochemical test results showed the integral hydrophobic cement mortar provided a long-term protection for the embedded steel bar. The hydrophobicity and pozzolanic effect of the hydrophobic SF made cement mortar a high strength, good water resistance and corrosion resistance. Additionally, the global warming potential (GWP) of hydrophobic cement mortar was calculated based on life cycle assessment (LCA). It showed that the GWP and environmental impacts of hydrophobic cement mortar reduced.

Study on the influential effect of different CaCO3 particle sizes on the internal pore structure of starch/fiber foaming composite materials

Starch/fiber foaming material is an ideal alternative to non-degradable cushioned packaging products. There still needs to be an improvement in the performance of such materials, which affects their promotion and application. The pore structure significantly impacts the performance of starch/fiber foam composite materials, so adjusting the internal pore structure of foam materials is also an important method to improve the performance of foam materials. In this study, the CaCO3 with particle sizes of 50 µm,5 µm, 500 nm, and 50 nm were separately mixed into the slurry as nucleating agents and composite materials were prepared through a hot pressing process to control the pore structure by adding nucleating agents of different particle sizes. Observing through Scanning Electron Microscope(SEM), the internal pore size of the composite material with 50 µm particle size CaCO3 is about 800 µm. The composite material made of CaCO3 with a particle size of 50 nm has a pore size of only 333 µm. It has decreased by 58% compared to the composite material with 800 µm CaCO3. The results indicate that as the size of CaCO3 particles decreases, the composite material exhibits more uniform and dense vesicles, and its water resistance, thermal stability, and corrosion resistance have also improved to a certain extent.The material made by adding the smallest particle size CaCO3 has a minimum degradation rate of about 10.5% in 30 days, and the buffering efficiency is highest when the stress is greater than 2 MPa, reaching about 22%.

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A high‐performance and sustainable structural functional material has been developed from natural pinewood, enabled by the unique ionic bond. The obtained material shows good water resistance, thermal conductivity, thermal stability, UV resistance, corrosion resistance and antibacterial properties. This material has promising applications in waterproof enclosure structure, underfloor heating, UV resistant protective cover, and anti‐corrosion materials, etc. image

Water and oxygen corrosion resistance of SiCf/SiC–SiYBC composites prepared by reactive melt infiltration at 1300°C –1500°C

AbstractIn this work, the static water and oxygen corrosion behavior of SiCf/SiC–SiYBC composites was systematically studied at 1 300°C to 1 500°C. With the increase in corrosion temperature from 1 300°C to 1 500°C, both the residual strength and strength retention rate of SiCf/SiC–SiYBC composites initially increased and then decreased. The highest strength retention rate achieved was 132%, which was 35% higher than that of SiCf/SiC composites. During water and oxygen corrosion of composites, self‐healing boron silicate glass and the Y2Si2O7 phase with excellent resistance to water and oxygen were generated in situ. The oxidation products are fluid at high temperatures and can fill internal pores and microcracks, thus improving the residual strength of the SiCf/SiC–SiYBC composite. The water corrosion resistance of SiCf/SiC–SiYBC materials has been confirmed to be superior to that of SiCf/SiC composites.

Photothermal insulation polydimethylsiloxane coating based on phase change materials for anticorrosion applications

Phase change materials have potential to enhance the heat preservation properties of coatings. Herein, an assumption was proposed that the phase change material can store the heat generated by photothermal materials and release it near the phase transition temperature. A photothermal heat-preserving polydimethylsiloxane coating was prepared based on PEG@CuS phase change nanofillers, which was proven to have thermodynamic stability through molecular dynamics simulations. This composition exhibited thermodynamic stability, as evidenced by molecular dynamics simulations. In the composite coatings, CuS nanofillers generate heat through solar energy, while PEG stores heat via the phase change process. Due to the phase change process of nanofillers and the low heat dissipation coefficient of composite coating, the composite coatings demonstrate excellent heat preservation property as verified by finite element calculations. Furthermore, we investigated the water permeation processes and corrosion resistance of the coating using distribution of relaxation time analysis and finite element calculations. The results indicate that the composite coatings process a diffusion coefficient of approximately 1.99 × 10-15 m·s−1, providing water resistance for up 20 days. This strategy presents an innovative approach to extend the functionality of coatings in heat management function.

О МЕХАНИЗМАХ ОБРАЗОВАНИЯ НАНОСТРУКТУРНЫХ ЭЛЕКТРОЛИТИЧЕСКИХ ПОКРЫТИЙ Fe-Ni, Co-Mn, Ni-Cr С ФУНКЦИОНАЛЬНЫМИ СВОЙСТВАМИ

The evolution of modern industry is impossible without the development of new materials and technologies. Nanostructured coatings, in particular electrolytic coatings, are among the most demanded in mechanical engineering. The purpose of this work was to study the different mechanisms of obtaining Fe-Ni, CoMn, Ni-Cr galvanic alloys and their relationship with the specified universal physical and mechanical properties. Fe-Ni alloy is characterized by high microhardness and corrosion resistance in sea water, low cold brittleness; Co-Mn – by a specified phase composition (α-Co >> α-Mn, amorphous and metastable phase Co(OH)2); Ni-Cr – by high coating microhardness, specified phase composition. The main methods of production: high-frequency alternating current for Fe-Ni and Co-Mn alloys; introduction of a special additive (carbamide or H-acid) for Ni-Cr alloy. The main mechanisms are: Fe-Ni due to phase transition α-Fe ε-Fe; Co-Mn by means of high-frequency alternating current and carbamide addition, providing a specified phase composition; Ni-Cr by means of stationary method of addition of H-acid (high-chromium alloy of 68 mass percent of Cr) and carbamide (low-chromium alloy of 25 mass percent of Cr). Recommended uses for electroplating: Fe-Ni – for protection of oil and gas production equipment in the Arctic; CoMn – in modulation systems and as a nanocatalyst in the Fischer-Tropsch synthesis reaction; Ni-Cr – for corrosion-resistant protective coatings in petrochemistry and for resistive elements.

Sustainable ultra‐strong thermally conductive wood‐based antibacterial structural materials with anti‐corrosion and ultraviolet shielding

AbstractIn light of the uprising global development on sustainability, an innovative and environmental friendly wood‐based material derived from natural pinewood has been developed as a high‐performance alternative to petrochemical‐based materials. The wood‐based functional material, named as BC‐CaCl2, is synthesized through the coordination of carboxyl groups (−COOH) present in pinewood with calcium ions (Ca2+), which facilitates the formation of a high‐density cross‐linking structure through the combined action of intermolecular hydrogen bonds. The as‐prepared BC‐CaCl2 exhibits excellent tensile strength (470.5 MPa) and flexural strength (539.5 MPa), establishing a robust structural basis for the materials. Meanwhile, BC‐CaCl2 shows good water resistance, thermal conductivity, thermal stability, UV resistance, corrosion resistance, and antibacterial properties. BC‐CaCl2 represents a viable alternative to petrochemical‐based materials. Its potential application areas include waterproof enclosure structure of buildings, indoor underfloor heating, outdoor UV resistant protective cover, and anti‐corrosion materials for installation engineering, and so forth.image

Application of polymer cement repair mortar in underground engineering: A review

Polymer-modified cementitious repair materials have gained attention as innovative and environmentally friendly construction materials due to their superior water retention, adhesion, freeze-thaw resistance, corrosion resistance, air permeability, and shrinkage resistance compared to ordinary repair materials. Adding a small amount of polymer can alter the concrete microstructure and form a composite material through the interaction between polymer film formation and cement hydration. This review shows that adding a certain percentage of polymers to concrete can improve the physical, fresh properties, durability, mechanical properties and microstructural development of concrete and improve the effectiveness of concrete repair treatment of underground structures. The discovery of different types and amounts of polymer cement from both physical and chemical perspectives can significantly enhance the performance of cement mortar. Various modifications, such as fibers and nanomaterials are explored to improve the properties of polymer cement for optimal treatment results. Finally, this paper summarizes key findings and provides recommendations for future research.

Crosslinked succinic acid based non-isocyanate polyurethanes for corrosion resistant protective coatings

Non-isocyanate polyurethanes (NIPUs) are considered as safer alternatives to toxic isocyanate-based polyurethanes (PUs). However, NIPU coatings are generally known for their poor water resistance due to the presence of pendant hydroxyl groups in the structure unlike traditional PUs. In this work, solvent-borne crosslinkable NIPU coating formulations were developed in a non-toxic solvent, diethylene glycol diethyl ether, and their coatings properties were evaluated. The crosslinking chemistry involved acid catalyzed transetherification of a commercially available crosslinking agent hexa(methoxymethyl) melamine (HMMM) with the NIPU hydroxyl groups. The crosslinked NIPU coatings showed good thermal stability (up to 245 °C), high pencil hardness (up to 3H), strong adhesion to metal substrates (adhesive strength up to 9.04 MPa), high resistance to water and good salt-water corrosion resistance. The formulations were also applied successfully for dip coating of copper specimens with complex and hard to reach surfaces. Finally, pigmented solvent-borne coating formulations were also demonstrated. All these results highlight the potential of NIPU resins for the application in industrial coatings substituting traditional petroleum-based polyol resins used currently.

Effect of Si content on the microstructure and properties of CrSi coatings for ATF cladding

Microstructure, mechanical properties, corrosion resistance and high-temperature oxidation resistance of four CrSi coatings with different Si content ranging from 0 at% to 67 at% were investigated. With increasing Si content from 11 at% to 67 at%, the main forms of Si exist the coatings were detected to be Cr3Si, Cr5Si3 and CrSi2, respectively. All the CrSi coatings own higher nano-hardness due to the formation of intermetallic. For Si content ≤33 at%, the CrSi coatings showed good corrosion resistance in static pure water of high temperature and pressure. However, the higher Si content (67 at%) led to the dissolution of Si in the form of [Si(OH)]4, as well as insufficient Cr to form a continuous Cr2O3 layer. The high-temperature oxidation tests showed that the coating with 11 at% Si content exhibited the best oxidation resistance than other coatings, due to the formation of outermost Cr2O3 layer, stable Cr3Si phase and inner Zr2Si. Our study indicates that the coating with 11 at% Si content displays good comprehensive properties and could be used as a candidate material for ATF coatings.

Airborne hydrocarbon induced multifunctional coating towards bouncing characteristics, icing delaying, hot-water repellency, and anti-corrosion on copper

Some studies have confirmed copper coating can realize superhydrophobicity after exposure to air. However, the comprehensive characteristics of the special wettable coating such as surface energy, bouncing behavior, hot water repellency, icing delaying, and corrosion resistance are still not well understood. Here, without further chemical processing, an electrodeposition technique creates a superhydrophobic layer on a copper substrate. The wettability versus different exposure routes is investigated. As a result, the slow oxidation of Cu and adsorption of airborne hydrocarbon contribute to a low rolling angle and enhanced water droplet bouncing ability. The coating displays strong 95 °C hot water repellency, icing delaying (∼78s), and great anti-corrosion ability, which also has a high protection efficiency (98.84%) and an improved coating resistance of 2.198 × 105 Ω cm2. The multifunctional properties are attributed to the airborne hydrocarbon and the constructed hierarchical structure. This preparation process avoids complex chemical modification and it can provide a new strategy for designing multifunctional coating for surface protection on metals.