Corrosion Resistance Of Materials Research Articles

A kind of biological hybrid material – Trichoderma viride/FeOOH as a durable anticorrosion coating for steel

Development of anticorrosive materials is critical and the most efficient way in the innovation of solving corrosion problems. Biological hybrid materials have unique advantages and great potential in the corrosion resistance materials. Herein, a new biological hybrid material was designed by the interaction of Trichoderma viride(T. viride) and Fe-based nanomaterials for anticorrosion of steel in artificial seawater. The results showed that the biological hybrid material - T. viride/FeOOH with a cobweb was successfully synthesized by self-assembly of T. viride and Fe-based nanomaterials on the steel surface. T. viride/FeOOH with thickness only 60 μm exhibited good anti-corrosion effect and its anti-corrosion efficiency reached up to 88.97 %. Further, T. viride/FeOOH was fairly stable, and its corrosion resistance was still up to 87.45 % after 20 d of continuous immersion in seawater. This study provides a new perspective and option for anti-corrosion control of steel in marine environment.

Firing properties and corrosion resistance of mullite‐Al2TiO5 saggar materials

AbstractConventional refractory materials used for calcining ternary lithium‐ion battery cathode materials, such as mullite, cordierite, and magnesia‐alumina spinel, are vulnerable to attack by Li(NixCoyMn1−x−y)O2 (LNCM) materials and therefore have a short service life. In order to improve the corrosion resistance of refractory materials to LNCM materials, mullite‐Al2TiO5 materials with different contents were synthesized in this paper by using calcined mullite powder, TiO2 powder, and La2O3 powder as raw materials, which were calcined at 1500–1600°C temperature, respectively. In this study, the potential of the materials for the preparation of LNCM materials was investigated in terms of its physical properties, resistance to the corrosion of LNCM materials, and resistance to thermal shock. The results showed that mullite‐Al2TiO5 composites can be successfully synthesized at 1500–1600°C, and the physical properties of the materials met the production requirements. The prepared mullite‐Al2TiO5 composites also exhibited better physical properties, good corrosion resistance, and proper thermal shock resistance compared with mullite refractories.

Corrosion behavior of graphene coated Ti-6Al-4 V alloy by anodic plasma coating method

In this study, graphene layers were deposited onto Ti-6Al-4 V plates by Thermionic Vacuum Arc (TVA) deposition technology to improve the corrosion resistance of biomedical material. For this purpose, the distance from the sample (4 and 7 cm) and duration of coating (5 and 15 mins) parameters were tested. The corrosion performance of the sample was carried out using electrochemical tests in 0.9 wt% NaCl medium. Furthermore, the applied coatings were characterized by using FESEM, AFM, EDS, and FTIR devices. The microstructural findings revealed that the graphene coating was found dispersed in the grain and grain boundaries and was applied successfully to the surface of Ti-6Al-4 V for all applied TVA parameters. In general, the corrosion potential of the coated sample was more anodic when compared to the uncoated sample. The passivation area of the sample TP21 was more prominent, and the corrosion current was lower than in other samples. Furthermore, the polarization resistance was higher, and the corrosion rate was 8 times lower compared to the uncoated sample. Graphene coatings are promising anticorrosion coating materials for Ti-6Al-4 V.

Enhanced corrosion resistance of a ZrCuNiAl bulk metallic glass in simulated groundwater by minor crystallization

Understanding the corrosion behaviors of bulk metallic glasses (BMGs) in practical working environment is essential for the applications of BMGs as corrosion resistance materials. The present work investigated the corrosion behaviors of Zr50.7Cu28Ni9Al12.3 (at. %) BMG and also its heat treated alloys with different volume fraction of crystalline phase in a solution simulating groundwater. It was shown that the corrosion of the present ZrCuNiAl alloy is induced by pit etching and Cu would be aggregated at the corrosion positions in a form of Cu2+ ions. Zr, Ni and Al would inversely be dissolved by the simulated groundwater and so were lack at the corrosion positions, and they are probed as form of Zr4+, Ni2+ and Al3+ ions on the corrosion surface, which supports the formation of metal oxides ZrO2, CuO, NiO and Al2O3. The experimental results discover a corrosion resistance trend first enhancing and then reducing with increasing crystalline phase volume fraction, proving that minor crystallization in fact also improve corrosion resistance in this BMG system, but large volume fraction of crystalline phases would deteriorate the anti-corrosion performance of BMGs. Thus the amorphous state itself improves corrosion resistance of the studied alloy.

Preparation of CMAS, LZS glass-ceramics and study of the glass ceramics anti-corrosion properties in liquid leadbismuth eutectic at 500°C

Liquid lead-bismuth eutectic (LBE) was an important candidate material for the fourth generation reactor coolant. Its high temperature and heavy metal corrosion conditions put forward higher requirements for the corrosion resistance of reactor structural materials. As a new kind of special material, glass-ceramic material, which possesses the excellent properties of glass and ceramics, has good mechanical property, wear-resisting property and corrosion resistance. The LBE corrosion behavior of glass-ceramics at typical operating temperatures of nuclear reactors was investigated. The lead bismuth corrosion test was carried out under the condition of oxygen saturation at 500°C for 500h. The lead bismuth corrosion resistance of the two glass ceramic samples in static LBE was analyzed by means of scanning electron microscope (SEM) and X-ray diffraction (XRD). After 500 h corrosion in oxygen saturated liquid LBE at 500°C, there was no obvious corrosion on the surface of CMAS glass ceramics. Its dense microstructure and stable phase composition effectively prevented the penetration of Pb and Bi elements, and had good resistance to corrosion; The surface of LZS glass ceramics was covered with a layer of loose and porous compounds, and the thickness of the corrosion zone was 10 μm, which occurred a certain degree of lead-bismuth corrosion, and its corrosion resistance was poor. The results showed that under the same corrosion conditions, no lead bismuth corrosion behavior was found on the surface of CaO-MgO-Al2O3-SiO2 (CMAS) glass-ceramic, while there was a corrosion layer with a thickness of about 10 μm on the surface of Li2O-ZnO-SiO2 (LZS) glass-ceramic, indicating that the lead bismuth corrosion resistance of CMAS glass ceramics was significantly better than that of LZS glass ceramics.

INTRODUCTION AND LITERATURE REVIEW OF CORROSION AND BIOFOULING IN MARINE ENVIRONMENT

This study aims to increase the power and the performance of marine structures by protecting them from corrosion and biofouling, which cause reduction of the vessels power. There are many factors in marine environment such as salinity, pH, temperature, and velocity, which cause corrosion. There are three main reasons concerning the study of corrosion. These reasons are safety, economics, and conservation. In addition, there exists the aquatic organism bio-film, which covers the vessels hull. This phenomenon called fouling and it results in increasing hydrodynamic drags, lower the maneuverability of the vessels and increase the fuel consumption. All these factors lead to the deficiency of ships performance. There are many methods that can be used to prevent vessels from the results of fouling and corrosion, among these methods coating i.e. using a highly corrosion resistant material on the ship hull and cathodic method i.e. using zinc for electro mechanic interaction could be effective if implemented properly.

Experimental Investigation on Improving Lifetime of Peripheral Pump Impeller under Cavitation Using Different Techniques

The industry is becoming more interested in peripheral pumps because they are inexpensive, have low specific speeds, and are small. One of the more serious problems that may occur with any pump is cavitation. That has a significant impact on pump components, particularly the impeller. This work presents a detailed experimental study on prolonging impeller lifespan under cavitation conditions by studying the effect of impeller surface finishing and coatings on its lifetime. For this purpose, seven impellers, in addition to the original one of the peripheral pump, had prepared and treated. Three impellers with three different levels of arithmetic surface roughness (Ra) were produced using a low-cost and customizable hand grinding procedure. And four impellers have been coated thermally with four different erosion-resistant composite materials. All of the impellers were cavitated for 300 minutes at normal and one at high water temperatures. The result showed that the mass loss percentages with the smallest (Ra) of 0.35µm, and coated with yellow epoxy were 84.86% and 48.50% lower than the original impeller, respectively. Thus, improving the quality of impeller surface finishing, and thermal coatings are excellent method for increasing the impeller's cavitation erosion resistance and thereby extending its lifetime.

Research Progress on Laser Cladding Alloying and Composite Processing of Steel Materials

Laser cladding technology is a reliable and efficient surface modification technology, which has been widely used in surface alloying and composite processing of steel materials. Firstly, the characteristics of laser cladding technology were introduced, and the effects of process control and the material system on the geometric shape, size, microstructure, and properties of cladding coating were analyzed by summarizing the research results of laser cladding on steel surfaces. The results show that with the increase of laser power, the dilution rate and width of the cladding coating increase, and the grain becomes coarse. Thus, the wear resistance deteriorates. Compared with alloy cladding coating, composite cladding coating exhibits better wear and corrosion resistance, but the plastic toughness is worse than alloy cladding coating. The research progress of surface alloying and composite processing of steel worldwide was analyzed from various aspects. Current results suggest that laser cladding alloying and compounding can enhance the wear resistance and corrosion resistance of steel materials. Based on the summary of the current research results, the development prospect and planning of laser cladding technology in the field of surface alloying and composite processing of steel are further pointed out.

Corrosion-resistant polymer-based nanocomposite materials with a high level of microwave absorption and soft magnetic materials based on iron oxide nanopowder obtained by electroerosion dispersion

Nanopowder of iron oxide (mainly Fe3O4) has been obtained by electroerosion dispersion method and was used for manufacturing of gradient polymer-based microwave absorbing materials which absorb (1) on 36.6 GHz with a level of absorption of 99% (with a maximum penetration −40 dB and reflection −23 dB) and (2) on 10 GHz and 36.6 GHz with an absorption of 90% and 98.4%, correspondently (with a maximum reflection −18 dB and −10 dB and penetration −40 dB and −60 dB, respectively). It was demonstrated, that change of magnetic properties of the absorbing material under mechanical load can be used for non-destructive control. Sintered under high pressure-high temperature conditions (2 GPa, at 900, 1000, 1100, 1200 and 1300 °C for 4 min) iron oxide nanopowder in presence of hexagonal boron nitride (hBN) demonstrated soft magnetic behavior. Electron Backscatter Diffraction (EBSD) study has showed that during sintering the grains have grown beyond the superparamagnetic size limit inspire short annealing time. The structure of sintered materials was investigated using X-ray diffraction with a full-profile fitting procedure. The materials sintered at 2 GPa at 900 and 1000 °C contained 75–80 wt% of FeO and 25–20 wt% Fe. Materials sintered at 1100 oC, along with 32 wt% FeO and 2 wt% Fe, contained a significant amount of Fe3N: 66 wt%. However, materials sintered at 1200–1300 °C contain almost pure Fe3N phase. Thus, under conditions of high pressures and temperatures with increasing sintering temperature, reduction of iron oxide was observed, followed by its nitriding with nitrogen released from the boron nitride, which led to a reduction of coercive force and thus improving soft magnetic characteristics of the sintered materials. The scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM/EDX) study of the sample, sintered at 1300 oC showed approximate composition of Fe3N0.8C0.3-0.6O0.06-0.3.

High-Throughput Electrochemistry to Study Materials Degradation in Extreme Environments.

Electrochemistry has been used for decades to study materials' degradation in situ in corrosive environments, whether it is in room-temperature chemically aggressive solutions containing halide ions or in high-temperature oxidizing media such as pressurized water, liquid metals, or molten salts. Thus, following the recent surge in high-throughput techniques in materials science, it seems quite natural that high-throughput electrochemistry is being considered to study materials' degradation in extreme environments, with the objective to reduce corrosion resistant alloy development time by orders of magnitude and identify complex degradation mechanisms. However, while there has been considerable interest in the development of high-throughput methods for accelerating the discovery of corrosion resistant materials in different environments, these extreme environments propose formidable and exciting challenges for high-throughput electrochemical instrumentation, characterization, and data analysis. It is the objective of this paper to highlight those challenges, to present relatively new efforts to tackle them, and to develop research perspectives on the future of this exciting field. This Perspective is articulated around four main interconnected topics, which must be conjointly considered to enable corrosion resistant alloy design using high-throughput electrochemical methods: (1) high-throughput processing methods to develop material libraries, (2) high-throughput electrochemical methods for corrosion testing and evaluation, (3) high-throughput machine-learning augmented electrochemical data analysis, and (4) high-throughput autonomous electrochemistry representing the future of accelerated electrochemistry research.

Problems of brushless motors applying in electric drives

Тhe development of technologies, corrosion resistance, mechanical properties and temperature range of magnetic materials have recently improved significantly. As a result, machines with permanent magnets find a wider distribution in industries with a heavy operating mode, in electric drives of ship mechanisms and devices, in the military field, etc. The cost of rare-earth permanent magnets has decreased by a factor of five over the past two decades, while the corresponding specific magnetizing force has increased by a factor of three, which represents a 15-fold improvement in cost-benefit ratio and is essential for affordability by price. The article is devoted to the study of an electric drive with a brushless motor, as well as the definition of problems that arise in this electric drive and ways to overcome them.

Preparation of a thick NiAl/Al2O3 coating by embedding method and its corrosion resistance under supercritical water environment

One of the critical issues in the application of supercritical water oxidation technology is to improve the corrosion resistance of reactor materials. Use of Al2O3 coating is one of the most promising methods to address this issue. In this study, thick NiAl/Al2O3 coatings on Inconel 625 substrates were prepared by a consecutive pack embedding and in-situ thermal oxidation process. The effect of aluminizing and oxidation temperature on phase structure and coating thickness is studied. Results show the diffusion of Al from the exterior to the interior of the alloy matrix to form intermetallic compounds between Al and metal elements in the matrix (Ni, Cr, Mo, etc.). Moreover, the coating thickness can reach above 300 μm at the aluminizing temperature of 950 °C. Increasing the aluminizing temperature above 950 °C will not increase the coating thickness further. After high temperature oxidation subsequently, only phases of NiAl and Al2O3 were detected. The formation of Al2O3 layer can be ascribed to the surface oxidization of Al. And the NiAl between the alloy substrate and Al2O3 coating provides an interfacial layer that can alleviate the crack or exfoliation of ceramic coating due to the mismatching of thermal expand coefficient. The thick NiAl/Al2O3 coatings prepared by aluminizing 950 °C and oxidizing at 1100 °C exhibit satisfied corrosion resistance after supercritical water test. This work would provide a significant method to develop advanced ceramics coating for the corrosion resistance of alloys.

Study of concrete properties based on crushed stone sand mixture and fiber of fly ash of thermal power plants

Abstract The study aims to optimize the composition of the main composite, the components of which, in their joint presence, make it possible to obtain the most significant positive synergistic effect. The authors of this article used the fibers of fly ash from thermal power plants as a finely dispersed component added to the crushed stone sand mixture. The result of the study was a high-strength corrosion-resistant material consisting of a crushed stone sand mixture (CSSM) with the addition of the fibers of fly ash. The authors applied the thermogravimetric and standard methods to study and determine the performance and strength characteristics of the obtained material. The combined effect of a complex organic-mineral modifying additive and the cement with the fibers of fly ash provided a compacted and reinforced structure of cement stone. An optimal binder composition was developed, consisting of cement and fiber of fly ash. The authors of this article examined the physical-mechanical and structural-mechanical properties of a CSSM of fine-grained concrete reinforced with a complex additive of cement, fibers of fly ash, and a superplasticizer. The study also provided technological solutions for manufacturing a functional mixture of fine-grained concrete based on the developed complex organic-mineral additive.

A prediction model for carbonation depth of cement sheath of carbon capture utilization and storage (CCUS) wells

The cement sheath of CCUS well is vulnerable to carbonization corrosion upon protracted exposure to a CO2-rich setting, which reduces the strength of the cement sheath and increases the porosity, eventually leading to CO2 leakage. Predicting the carbonation depth and regularity of the cement sheath of CO2 injection wells allows an estimation of the service life , to ensure safe operation of CO2 injection wells. However, most of the current prediction models for CO2 corrosion depth are still semi-empirical models, which are fitted to experimental data but are not universally applicable. This may be resolved by our CO2 corrosion depth prediction model supported by the law of mass conservation, diffusion convection equation, and calcium precipitation rate. The influence of seven factors on the corrosion depth was analyzed and ranked. The rise in corrosion time, temperature, chloride ion content, CO2 partial pressure, water-cement ratio, and water saturation increases corrosion depth and CO2 content, in addition to porosity and permeability, while increasingly corrosion-resistant material causes the opposite effect. The cement sheath begins to be seriously corroded by CO2 partial pressure exceeding 10 MPa, chloride ion content over 0.20 mol/L, or temperature higher than 70 °C. Water saturation significantly affects corrosion, and the CO2 corrosion depth at 0.8 is 10.16 times that at 0.6. The CO2 content at the distance of 0.2 m–0.93 m from the corroded end surface basically does not change after 7 years of corrosion. Water-cement ratio increased to 0.48 provides conditions for a large amount of CO2 accumulation in the cement sheath. The addition of corrosion-resistant materials can reduce the initial porosity and permeability of cement sheath. The seven factors is ranked in descending order of influence as water saturation, corrosion-resistant material, water-cement ratio, CO2 partial pressure, corrosion time, chloride ion content, and temperature.

Corrosion resistance of polyurethane grouting material in landfill site

Landfill has been a common way to deal with municipal solid waste. It is critical to prevent the leakage of landfill leachate with corrosivity and biotoxicity in landfill sites. Non-aqueous reacting polyurethane grouting material has been demonstrated to have excellent water-barrier performance. This study aimed to verify the feasibility of non-aqueous reacting polyurethane grouting material application to landfills. The corrosion resistance of the grouting material was investigated using laboratory immersion tests with 14 chemical solvents. The corrosion resistance was evaluated based on the weight gain rate of polyurethane samples and their microscopic damage. The test results show that the polyurethane grouting material showed good resistance to acids (sulfuric acid, nitric acid and propionic acid), salt solutions (calcium chloride, ferric chloride, zinc sulfate and lead acetate) and landfill leachate. However, methyl phenol could lead to chemical degradation. Hydrochloric acid, gasoline and ammonia may cause minor damage to polyurethane. The results are expected to provide reference for evaluating the chemical corrosion resistance of polyurethane grouting materials in landfill sites.

Effects of phosphate additives on the wetting and corrosion resistance of high-chrome refractory materials to two slags

This study investigated the wetting, spreading, and infiltration behavior of the two slags (high-silicon slag and the high-calcium slag) on the two high-chrome refractories (with and without phosphate additives) in-situ using sessile drop tests combing thermodynamic simulation calculations. The wetting process of the slag samples on the two high-chrome refractories was recorded, and the apparent contact angle was measured by image processing technology. The microstructures and chemical compositions of the corroded samples were analyzed by scanning electron microscopy (SEM and EDS). The results showed that the addition of phosphate improved wetting resistance to the two slags and infiltration resistance to the high-silicon slag. However, the high-calcium slag showed the strong penetration and corrosion on the high-chrome refractory with phosphate additives, which was ascribed to the CaO, that could react with P2O5 and Cr2O3 in the high-chrome refractory with phosphate additives, producing a large amount of liquid phase, causing more damage.

Improving the Corrosion Resistance of Aluminum Alloy by Creating a Superhydrophobic Surface Structure through a Two-Step Process of Etching Followed by Polymer Modification.

A multifunctional aviation aluminum alloy with good superhydrophobicity and corrosion resistance was prepared by a two-step process of etching followed by polymer modification. Meanwhile, micro- and nanostructures formed on the processed sample. Compared with bare sample, the static liquid contact angle on the as-prepared sample was increased by 100.8°. Further polarization tests showed that the corrosion potential of such a sample increased, and the corrosion current density decreased obviously, thus suggesting that the corrosion resistance of the modified sample was significantly improved. The same conclusion was confirmed by subsequent impedance testing. The work is of great economic value and practical significance to enhance the corrosion resistance of aviation actuator materials and also lays a foundation for future hydrophobic application research in aeronautical engineering.

Inhibition of Phenol from Entering into Condensed Freshwater by Activated Persulfate during Solar-Driven Seawater Desalination.

Recently, solar-driven seawater desalination has received extensive attention since it can obtain considerable freshwater by accelerating water evaporation at the air-water interface through solar evaporators. However, the high air-water interface temperature can cause volatile organic compounds (VOCs) to enter condensed freshwater and result in water quality safety risk. In this work, an antioxidative solar evaporator, which was composed of MoS2 as the photothermal material, expandable polyethylene (EPE) foam as the insulation material, polytetrafluoroethylene (PTFE) plate as the corrosion resistant material, and fiberglass membrane (FB) as the seawater delivery material, was fabricated for the first time. The activated persulfate (PS) methods, including peroxymonosulfate (PMS) and peroxodisulfate (PDS), were applied to inhibit phenol from entering condensed freshwater during desalination. The distillation concentration ratio of phenol (RD) was reduced from 76.5% to 0% with the addition of sufficient PMS or PDS, which means that there was no phenol in condensed freshwater. It was found that the Cl- is the main factor in activating PMS, while for PDS, light, and heat are the dominant. Compared with PDS, PMS can make full utilization of the light, heat, Cl- at the evaporator's surface, resulting in more effective inhibition of the phenol from entering condensed freshwater. Finally, though phenol was efficiently removed by the addition of PMS or PDS, the problem of the formation of the halogenated distillation by-products in condensed freshwater should be given more attention in the future.

Effect of oxygen concentration on the corrosion behavior of Cr-coated Ni alloy in supercritical water oxidation environment

To improve the corrosion resistance of component materials in supercritical water oxidation (SCWO) environment, a 15 µm Cr coating was prepared on Alloy 625 by magnetron sputtering, and the effect of oxygen concentration (0 M, 0.16 M, and 0.94 M) on the stability of the Cr coating in an SCW environment was investigated. Results show that the stability of the Cr2O3 layer strongly depends on the oxygen concentration in the exposure environment. The protective Cr2O3 layer was transformed to soluble Cr(VI) species and dissolved in SCW containing 0.94 M oxygen. Except for Cr2O3, some Fe/Ni containing oxides were also detected. The stability of the Cr coating in SCW with different concentrations of oxygen is discussed.

A Mechanistic Model for the Predictive Maintenance of Heavy-Duty Centrifugal Fans Operating With Dust-Laden Flows

Abstract Heavy-duty centrifugal fans are employed for the transport of dust-laden flows in industrial plants, for cement or steel production, or in energy production of plants and mine ventilation systems. These applications require the disposal of huge amounts of suspended particles, which can lead to a gradual erosion of the machine parts where impacts take place. The wear of the fan components can lead to premature failure of the machine, threatening human safety and reliability of the whole plant. The assessment of the wear severity of the machine, according to the process parameters, can aid the plant owner in scheduling overhaul operations along with the operative life of the machine. Moreover, through a reliable estimation of the wear severity, fan manufacturers can optimize the whole machine design process, from the material selection to the warranty time assessment. This work aims to develop a semi-empirical method capable of estimating the erosion severity of centrifugal fans employed for heavy-duty operations. A mechanistic model which accounts for the erosion on the blade leading edge is proposed. The model is derived by means of an analytical approach and accounts for a number of operating parameters (i.e.,, fan geometry, fan operating point, particle concentration in the flow, fluid properties, and material erosion resistance). A comparison of the theoretical model to the computational fluid dynamic (CFD) simulation results obtained through the use of multiphase particle tracking is also provided to assess the reliability of the present method.