Corrosion Resistance Of Metals Research Articles

Estimation of the long-term corrosion resistance of typical metals in the coastal regions of the Russian Federation

ABSTRACT This study reports the characteristics of atmosphere corrosivity parameters on the sea coasts of Russia, namely, on the Arctic and Pacific Oceans and the Black Sea. It gives the results of predictions of long-term corrosion losses for standard metals on the sea coasts of Russia. Experimental data on the first-year corrosion losses found in 19 representative locations on the sea coasts were used for long-term predictions. Long-term corrosion losses of metals were calculated using a power-linear function. Two variants were used to estimate the values contained in the model: the n coefficient characterising the protective properties of corrosion products, and the time of stabilisation of the corrosion process (τstab). Ranges of possible long-term corrosion losses on the sea coasts of Russia are given for the two variants of predictions. An analysis of the results thus obtained is also given.

Methods of electrochemical research of corrosion resistance of metal treated with corrosion inhibitors, created on the basis of plant-based raw materials

The use of corrosion inhibitors based on raw materials of plant origin has been a poorly studied method of metal processing so far. To show the degree of corrosion protection, it is necessary to examine it. It is possible to do this by means of electrochemical research, the method of which consists of several methods: the extrapolation method; the polarization resistance method; the related methods. As a result of this method, a significant advantage of samples treated with corrosion inhibitors based on raw materials of plant origin was revealed.

Corrosion Resistance of Open Die Forged Austenitic Stainless Steel Samples Prepared with Different Surfaces

The use of corrosion-resistant metal materials in highly aggressive environments contributes to the preservation of the environment because it reduces the use of protective agents and coatings. Most metal objects are produced by some metal-forming process. It is well-known that plastic deformation affects the corrosion resistance of different metal materials in different ways. As a rule, austenitic stainless steels show a positive impact of plastic deformation on corrosion resistance, especially when hot deformed with protective surface oxide layers. However, most research carried out on these metals involves a carefully prepared surface which is either finely ground or polished. This paper investigates the corrosion resistance of cold-formed (open die forged) austenitic stainless steel in three different surface states for three different degrees of deformation. In doing so, we simulate possible damage to the treated surface and evaluate the stability of the material with respect to corrosion. Good corrosion resistance is shown for all three stages of deformation and for all three surface states, with some differences in the obtained results. Although the polished surface shows the highest corrosion resistance, as expected, the other two surfaces also demonstrate good results when exposed to aggressive environments. All of the results were statistically processed and presented. The results demonstrate the high usability of such materials in corrosion-aggressive environments with minimal danger of corrosion and minimal need to include additional surface protection agents, even against possible surface damage.

Estimation of long-term corrosion resistance of structural metals and mapping of continental territory of Russian Federation for various time periods

Estimation of long-term corrosion resistance of structural metals and mapping of continental territory of Russian Federation for various time periods

Mn-doped NiCo2S4 nanosheet array as an efficient and durable electrocatalyst for oxygen evolution reaction

The development of self-supported nanosheet materials with porous multiple active sites has enormous potential for the application of oxygen evolution reaction (OER). Herein, we reported a three-dimensional (3D) porous nanosphere Mn-NiCo2S4/NF catalyst for OER. As a result, the simple Mn doping strategy results in good electrocatalytic performance and outstanding stability. During the OER, the Mn-NiCo2S4/NF only needs a small overpotential of 220 mV (40 mV lower than pure NiCo2S4/NF) to achieve the current density of 10 mA cm−2, which is mainly due to a large number of exposed active sites and adequate pathways for mass diffusion and oxygen gas release. Moreover, Mn doping optimizes the electronic structure and thus facilitates electron transport, leading to superior electrocatalytic performance. The catalyst exhibits incredible corrosion resistance in 1 M KOH solution for 60 h or more. This work provides a valuable method to synthesize a low cost, high-efficiency, and corrosion resistant transition metal electrocatalyst for oxygen evolution using heteroatom doping strategy.

Effect of zinc nanoparticles on corrosion resistance of metals coated with composite materials based on epoxy oligomers

The article presents the results of a study of the anti-corrosion properties of composite materials based on epoxy resin modified with a mixture of AGM-9 and TGM-3 in a ratio of 1:3 and treated with zinc oxide nanoparticles. It is established that the coating of metals with epoxy oligomers and zinc nanoparticles significantly increases their resistance to corrosion. After holding in a 3.5% NaCl solution for 90 days, the hardness of metals without coating decreases by 22%, modified with AGM-9 and TGM-3 composites - by 11%, and modified with epoxy oligomers in combination with zinc nanoparticles-by only 3 %.

Application of microcrystalline complex modifiers for steel ladle treatment. Part 2. Results of elaboration of a technology for wide range of steels treatment

Results of application of microcrystalline complex modifiers (MCM) with alkaline and rare-earth metals at wide range steels ladle treatment. It was shown that substitution of silicocalcium by Si‒Ca‒Ba at deoxidation and modifying of wheel steel ena- bles to increase the metal impact toughness and decrease the wheels rejects. When making ingots of steel 20ГФЛ for railway transport, substitution of ferrocalcium by Si‒Ca‒Ba‒Sr alloy enables to increase the metal impact toughness at test temperature ‒60°С by 64%. The treatment of steel by microcrystalline alloys Si‒Ca‒Ba and Si‒Ca‒Ba‒Sr results in forming oxide-sulfide non-metallic inclusions with more than 2.5 times decreased sizes, as well as decreased general amount of nonmetallic inclusions in the steel. The danger of destruction, for example of a pipe lines, can be sharply decreased in case of metal micro-alloying by rare-earth metals. Forming of cerium and lanthanum hydrides will increase the resistance against hydrogen embrittlement and delamination of carbon and low-alloyed steels, as well as will increase metal corrosion resistance including a bacterial one. Application of MCM with calcium, barium and strontium for pipe steels treatment under comparable conditions enabled to increase calcium recovery by metal by 76.5%. Application of the Si‒Ca‒Ba modifier instead of silicocalcium for treatment of steel S355J2G3N enables to increase the metal impact toughness by 45‒57%. The treatment of metal for large ingots by complex modifiers Si‒Ca‒Ba‒Sr‒REM enables to decrease by 45‒50% the metal chemical non-homogeneity by liquation elements, to decrease contamination of metal by nonmetallic inclusions. Application of Si‒Ca‒Ba modifier results in decreasing consumption of cored wire and cost of the treatment by 38.5% and 11% correspodently. The use of Si‒Ca‒Ba‒Sr alloy results in a decrease of those indicators by 56% and 21% correspondently.

WEAR DYNAMICS ANALYSIS OF THE SUPPORTING STRUCTURES OF SHUNTING LOCOMOTIVES OF INDUSTRIAL RAILWAY TRANSPORT UNDER THE INFLUENCE OF MATERIAL CORROSION

Purpose. The research is aimed at obtaining new knowledge about the environmental influence on the supporting structures of the traction rolling stock of railways according to the corrosive wear parameter, the nature of the dynamics of this influence, as well as the evaluation of technical condition of the domestic traction rolling stock of industrial railways. Methodology. To obtain the relevant data, the author conducted aggregation and analysis of the results of ultrasonic thickness measurement of the main supporting structures of locomotives, obtained during eight years of the work to extend the service life of industrial transport locomotives. The supporting structures of series of locomotives presented in this study have a total range of service life of 25-48 years. They are located in different regions of Ukraine. Findings. The author found that among the surveyed fleet of diesel locomotives of industrial transport, the uniform corrosion level of supporting structures has a linear dependence on their service life with a rather low slope. Thus, according to the definitions of the normative documentation, which was relevant at the time of production of the rolling stock units that are the objects of this study, the material of the supporting structures (except for one particular case) belongs to the resistant group of metal corrosion resistance. Originality. Due to reasons such as the independence of industrial rolling stock from state-owned railway enterprises and the performance of maintenance work by various organizations, information on the general condition of the rolling stock of industrial transport is not readily available. The author for the first time collected statistical data on the state of industrial rolling stock and analyzed them. Practical value. The obtained results illustrate the development dynamics of equal corrosion of traction industrial transport structures, which, in turn, gives grounds for the subsequent improvement of the methodology of examining rolling stock units both during scheduled work and in order to extend the service life.

Development of technology for production of K52 strength class steels with low chromium content, cold and corrosion resistant in conditions of the casting and rolling complex

The results of experimental testing of production in the conditions of a casting and rolling complex (CRC) Vyksa Steel Works (VSW) of rolled products with a thickness of 8–10 mm with a reduced chromium content of strength class K52 to meet the requirements of the new guidelines of Rosneft on the corrosion resistance of metal in acidic environments. Based on the C–Mn–Si–Nb alloying system, a new chemical composition of steel with a reduced chromium content (0,40%) has been developed that provides a set of consumer properties — strength (tensile strength — 530–550 MPa, yield strength — 450–470 MPa), ductility (elongation — 28–34%), cold resistance (T50 below –80°C) and corrosion resistance against hydrogen cracking (CLR = 0%, CTR = 0%) and general corrosion in a CO2-containing medium (the rate of general corrosion is not more than 0,2 mm/year). It is shown that the variation of the chromium content in the range of 0,4–0,7% does not significantly affect the rate of general corrosion both under the influence of 5% sodium chloride solution and 5% sodium chloride solution with the addition of 0,40% sodium acetic acid solution when kept in an aggressive environment for 96 hours.

Follow-up ultrasonic vibration assisted laser welding dissimilar metals for nuclear reactor pump can end sealing

A novel follow-up ultrasonic vibration assisted welding process was proposed to reduce the common defects in laser welding of dissimilar metals for nuclear reactor pump can end sealing, such as unmixed zone, precipitated phase, and uneven element distribution. The influences of ultrasonic vibration on morphology, microstructure and property of C-276/304 laser-welded joint was analyzed. The results indicated that, the most significant ultrasonic vibration at welding position was achieved at parameters of 25 N pressing force and 13 mm distance from ultrasonic action point to welding position. By the application of follow-up ultrasonic vibration, the width of unmixed zone was reduced and the macro element distribution was homogenized due to the enhancement of molten convection. The average grain radius was refined from 1.03 μm to 0.55 μm because acoustic pressure in the molten pool reduced critical nucleus size rk and caused grain fragmentation. The higher diffusion coefficient and cooling rate caused by ultrasonic vibration suppressed element segregation, and thus the amount of precipitated phase decreased from 2.15% to 0.62%, which finally improved the intergranular corrosion resistance of weld metal. The load capacity of weld joint was improved by 12.6%, and the micro-hardness of weld metal was also increased, attributing to the grain refinement strengthening. The follow-up ultrasonic vibration process proposed in this paper provided an efficient, convenient and widely applicable process for laser seal welding of dissimilar metals for nuclear reactor pump can end sealing with higher qualities.

Nickel recovery from spent nickel-metal hydride batteries using LIX-84I-impregnated activated charcoal

Nickel (Ni) is a ferromagnetic and corrosion-resistant metal, whose demand has risen remarkably in recent years. Depletion of its sulphide and laterite ores has necessitated the need to find secondary sources of the metal. Spent nickel metal hydride (Ni-MH) batteries are considered to be possible sources of Ni recovery and recycling, and have been the object of some scientific investigations. This recovery is also important from environmental perspective, as disposal of the waste batteries constitute a significant release of Ni to the environment. However, previous studies have focused only on solvent extraction processes for Ni uptake from the battery leachates, neglecting the possibility of adsorption-based methods. Here, we optimized and achieved 99.6 % Ni uptake from the leachate of Ni-MH battery cathode, via the use of an adsorbing composite generated from 2-hydroxy-5-nonylacetophenone oxime (LIX-84I) and activated charcoal. Desorption with HCl led to the production of NiCl2.6H2O of 99.9 % purity, useful as a versatile industrial catalyst and for electroplating Ni onto other metals. The adsorption was endothermic and spontaneous, following a pseudo-second order kinetics while fitting best to Temkin isotherm model (R2 = 0.9913). This is the first report of an adsorption-based method optimizing Ni recovery from Ni-MH battery wastes.

A percolation theory for designing corrosion-resistant alloys.

Iron-chromium and nickel-chromium binary alloys containing sufficient quantities of chromium serve as the prototypical corrosion-resistant metals owing to the presence of a nanometre-thick protective passive oxide film1-8. Should this film be compromised by a scratch or abrasive wear, it reforms with little accompanying metal dissolution, a key criterion for good passive behaviour. This is a principal reason that stainless steels and other chromium-containing alloys are used in critical applications ranging from biomedical implants to nuclear reactor components9,10. Unravelling the compositional dependence of this electrochemical behaviour is a long-standing unanswered question in corrosion science. Herein, we develop a percolation theory of alloy passivation based on two-dimensional to three-dimensional crossover effects that accounts for selective dissolution and the quantity of metal dissolved during the initial stage of passive film formation. We validate this theory both experimentally and by kinetic Monte Carlo simulation. Our results reveal a path forward for the design of corrosion-resistant metallic alloys.

STUDY THE EFFECT OF COATING USING NANOPARTICLES ON THE CORROSION OF ALUMINUM ALLOY IN DIFFERENT SOLUTIONS

Corrosion resistance of metals is one of the most important topics for researchers. In this work, epoxy-TiO2 nanocomposite has been developed for protection of 6061AL alloy. The dip-coating technique used to deposit the coating on 6061 Al alloy substrate. Different concentrations of TiO2 NPs (1,3,5 )Wt% have been used to study the corrosion behavior in 3.5% NaCl medium. Also, 200,150 and 100 mm/min dipping speeds have been employed for 1%wt TiO2 to show their effects on coating layer and corrosion rate. Characterization of coated surfaces were investigated by AFM, FESEM andEDS,while theelectrochemical measurementswas using to evaluate protective nature of the coating. The results have shown that the corrosion rate has decreased with 1wt% of TiO2 NPs concentration. The corrosion rate (mm/y) of (7.131×10-4, 1.803×10-3 and 8.183×10-3) have been obtained with (1 , 3 and 5 wt% TiO2) respectively. The results have been confirmed by using a constant dip-coating speed of 200 mm/min, and the results of the corrosion rate for 200,150 and 100 mm/min have been 7.131×10-4, 7.984×10-4and 8.293×10-4 respectively. The morphology of coating film which characterized by SEM, have shown that the TiO2 NPs spread and was covered by epoxy very well. The AFM test used to study the surface average roughness of coating film where the Ra for sample with epoxy coating is24.4 nm and for sample with (epoxy _1%wt TiO2) is 1.508 nm.

Study of Corrosion Behavior in Resistance Spot Welds of Thin Sheets of Zinc-Coated Interstitial-Free Steel

The aim of this research is to investigate the corrosion behavior of the resistance spot-welded joints of the zinc-coated interstitial free steel (IF steel) in contrast to the steel. For this purpose, the corrosion behavior of the welds and base interstitial-free steel (IF steel) was investigated in two solutions including 0.1 M NaCl + 0.1 M NaOH and 0.1 M NaCl + 0.1 M H2SO4. Potentiodynamic polarization curves and electrochemical impedance spectroscopy test results showed that the corrosion resistance of the base metal and welds in 0.1 M NaCl + 0.1 M NaOH solution is higher than their corrosion resistance in 0.1 M NaCl + 0.1 M H2SO4 solution. It was found that the corrosion resistance of the IF steel base metal in both solutions is higher than that of the welds obtained by the steel. According to the cyclic polarization curves, it can be said that the passive film formed on the specimens in 0.1 M NaCl + 0.1 M NaOH solution is highly susceptible to pitting corrosion while the specimens do not show any passivation behavior in 0.1 M NaCl + 0.1 M H2SO4 solution and undergo severe uniform corrosion.

Estimation of long-term corrosion resistance of structural metals and mapping the continental territory of the Russian Federation for various time periods

ABSTRACT The results of predictions concerning the long-term corrosion losses of structural metals in the continental territory of Russia with rural atmospheres and in certain locations with urban atmospheres are presented. A power-linear model is used to predict long-term corrosion losses. Two variants for estimating the coefficients in the model are used. The first variant is presented in ISO 9224 international standard (ISO variant). In the second variant (the new variant), new dose–response functions (DRF N ) were used to predict the first-year corrosion losses of metals. In the new variant, the time for corrosion rate stabilisation (τ stab) is taken to be 6 years. Moreover, the stochastic relationship between the n coefficient, which characterises the protective properties of corrosion products, with the atmosphere corrosivity is used. Based on the predictions obtained for long-term corrosion losses, mapping of the territory of Russia is given for the two variants.

Based on the synergistic effect of Mg2+ and antibacterial peptides to improve the corrosion resistance, antibacterial ability and osteogenic activity of magnesium-based degradable metals.

To overcome the restricted degradation, poor antiacterial and osteoindctive problems of magnesium and its alloys, this study presented the spinning coating of an antimicrobial peptide (AP)-loaded silk fibroin (SF) composite onto a corrosion-resistant MgO-coated AZ31 Mg alloy via anodization (aMgO) and electrodeposition (eMgO) methods. The composite coatings not only created a smooth and hydrophilic surface, but also obviously improved the corrosion resistance according to the test of corrosion potential and current density. The colonization of E. coli on MgO-AP composite coatings was significantly reduced as compared to the MgO layers, due to the potential synergetic effects of APs and Mg2+. Compared with the bare AZ31, the composite coating inhibited the corrosion of the substrate and the release of Mg2+, supported the adhesion, spreading and proliferation of osteoblasts, and presented a significantly improved osteogenic differentiation trend. Therefore, the MgO-AP composite coating, which had both antibacterial and bone-promoting abilities, was expected to be applied for surface modification of magnesium alloy implants to solve the clinical problems of bacterial infection and poor osseointegration.

Применение защитных покрытий для обеспечения коррозионной стойкости основного металла фонтанной и трубопроводной арматур объектов газодобычи

Применение защитных покрытий для обеспечения коррозионной стойкости основного металла фонтанной и трубопроводной арматур объектов газодобычи

Structure and properties of powders obtained by electrodispersion of corrosion-resistant metal waste in kerosine

The results of experimental studies of the structure and properties of electroerosive high-chromium powders obtained in kerosene are presented. The high efficiency of using the electrodispersing technology is shown, which provides for obtaining new corrosion-resistant powder materials suitable for industrial use at low energy costs.

Evaluation of mechanical properties, in vitro corrosion resistance and biocompatibility of Gum Metal in the context of implant applications

In recent decades, several novel Ti alloys have been developed in order to produce improved alternatives to the conventional alloys used in the biomedical industry such as commercially pure titanium or dual phase (alpha and beta) Ti alloys. Gum Metal with the non-toxic composition Ti–36Nb–2Ta–3Zr–0.3O (wt. %) is a relatively new alloy which belongs to the group of metastable beta Ti alloys. In this work, Gum Metal has been assessed in terms of its mechanical properties, corrosion resistance and cell culture response. The performance of Gum Metal was contrasted with that of Ti–6Al–4V ELI (extra-low interstitial) which is commonly used as a material for implants. The advantageous mechanical characteristics of Gum Metal, e.g. a relatively low Young's modulus (below 70 GPa), high strength (over 1000 MPa) and a large range of reversible deformation, that are important in the context of potential implant applications, were confirmed. Moreover, the results of short- and long-term electrochemical characterization of Gum Metal showed high corrosion resistance in Ringer's solution with varied pH. The corrosion resistance of Gum Metal was best in a weak acid environment. Potentiodynamic polarization studies revealed that Gum Metal is significantly less susceptible to pitting corrosion compared to Ti–6Al–4V ELI. The oxide layer on the Gum Metal surface was stable up to 8.5 V. Prior to cell culture, the surface conditions of the samples, such as nanohardness, roughness and chemical composition, were analyzed. Evaluation of the in vitro biocompatibility of the alloys was performed by cell attachment and spreading analysis after incubation for 48 h. Increased in vitro MC3T3-E1 osteoblast viability and proliferation on the Gum Metal samples was observed. Gum Metal presented excellent properties making it a suitable candidate for biomedical applications.

Graphene Oxide/Polyaniline Nanocomposites Used in Anticorrosive Coatings for Environmental Protection

In recent years, metal corrosion causes serious threats to the economy of the world and the living environment. Hence, it is very important to seek non-toxic and environmentally friendly materials with metal anti-corrosion properties for the sustainable development of society. The barrier properties of graphene oxide (GO) and the special electrochemical property of polyaniline (PANI) can significantly improve the corrosion resistance of metals. Herein, we developed an in-situ polymerization method to prepare graphene oxide/polyaniline (GO/PANI) nanocomposites with unique anti-corrosion properties. The obtained GO/PANI nanocomposites were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, thermalgravimetric analysis, UV–vis spectroscopy and scanning electron microscopy. The as-prepared composite materials were uniformly dispersed in epoxy resin to prepare anticorrosive coatings and coated on the surface of steel. The anti-corrosion performance of the coatings was measured by electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization technique. The EIS results showed that the total impedance of epoxy/GO/PANI coatings is greater than epoxy/PANII coatings, and the impedance module value can reach 8.67 × 108 Ω·cm2. In general, it is concluded that the anti-corrosion performance of GO/PANI coating is significantly higher than PANI coating and pure GO coating.