Статті в журналах: "Acid, salt, alkaline corrosion"

1

Scepanovic, Jelena, Safija Herenda, Fehim Korac, Darko Vuksanovic, and Dragan Radonjic. "Protection of fuel filter with alkaline and acid zinc coatings." Glasnik hemicara i tehnologa Bosne i Hercegovine, no. 53 (December 18, 2019): 1–8. http://dx.doi.org/10.35666/ghtbh.2019.53.01.

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Galvanic coatings are applied so that the surface of the base material obtains appropriate properties, corrosion resistance, durability, aesthetic appearance, and long-term application in the appropriate industry. In this paper, the aim was to protect steel fuel filters with alkaline and acid zinc coatings of different thicknesses. The coating of zinc, which is applied from the alkaline electrolyte, provides good corrosion protection with excellent coating flexibility. The thickness of the coating by the X-ray fluorescence method was tested, followed by coating tests, corrosion resistance, and electrochemical tests. The results of adhesion showed a high quality coating, as no corrosion occurred during the test. The corrosion resistance tested by the salt chamber method speaks of the appearance of white and red corrosion. On alkaline electrolyte coatings, white corrosion occurred after 168 hours of exposure to the salt test, while on white zinc samples there was a white corrosion after 240 hours of exposure. Tafel polarization diagrams have been determined: corrosion potentials, current intensities, anode and cathode Tafel coefficients and calculated corrosion rates. The active and passive corrosion zone is determined by the cyclic voltammetry.

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Byoun, Young Min, Jin Hwan Jeong, Jong Kyu Park, Sun Kyo Seo, and Chi Hwan Lee. "Effect of Alkaline Phosphate-Permanganate Conversion Coating on the Corrosion Resistance of AZ91D Magnesium Alloy." Advanced Materials Research 974 (June 2014): 43–49. http://dx.doi.org/10.4028/www.scientific.net/amr.974.43.

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Alkaline phosphate-permanganate conversion coating, chrome-free conversion coating was studied for corrosion resistance of AZ91D magnesium alloy. Also, conventional acid phosphate -permanganate conversion coating was studied for comparison. Analysis and morphology observation for conversion coating layers was investigated in details by using SEM-EDS, XRD. SEM observation showed that a lot of cracks in surface and interface between conversion coating layer and AZ91D magnesium alloy substrate was observed in acid conversion coating, whereas cracks was not almost observed in alkaline conversion coating layer. SEM-EDS and XRD analysis showed that the main elements of both alkaline and acid conversion coating were Mg, O, K, P and Mn. It was found that both conversion coating layers was consisted of MgO, Mg (OH)2and MnO2. Salt spray test showed that the alkaline conversion coating have a good corrosion resistance compared with acid conversion coating.

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3

Yang, Xiao Ke, Yun Ying Fan, Ye Hua Jiang, and Zu Lai Li. "Study on Chromium-Free Color Passivation for Zinc Coating Treated with Silicate." Advanced Materials Research 154-155 (October 2010): 1301–4. http://dx.doi.org/10.4028/www.scientific.net/amr.154-155.1301.

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This paper mainly focuses on how the silicate liquid composition of chromium-free color passivation affects on passivation result, and confirmes the optimum passivation conditions, and uses two zinc plating system of alkaline and acid deposition. Silicate passivation system is compared with hexavalent chromium passivation technology and the results showed that: the appearance and corrosion resistance of passive films formed on zinc coatings plated with alkaline system are better than samples plated with acid system, and have the same corrosion resistanc with hexavalent chromium passivation. The silicate passivation films can keep 200 hours with no white rust in neutral salt spray test.

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4

Sun, Weixiang, Yupeng Liu, Tinghua Li, Siwen Cui, Shougang Chen, Qiangliang Yu, and Daoai Wang. "Anti-corrosion of amphoteric metal enhanced by MAO/corrosion inhibitor composite in acid, alkaline and salt solutions." Journal of Colloid and Interface Science 554 (October 2019): 488–99. http://dx.doi.org/10.1016/j.jcis.2019.07.035.

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Wei, Shao Ming. "Progress of Studies on Durability of FRP Rods Used in Civil Engineering." Applied Mechanics and Materials 395-396 (September 2013): 451–54. http://dx.doi.org/10.4028/www.scientific.net/amm.395-396.451.

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Fiber reinforced polymer ( FRP) rods have a broad application in civil eng ineering field used as a material substiting steelbars. Based on the domestic and abroad research, the durability of the fiber reinforced polymer (FRP) rods undermultifarious environmental conditions is summarized in this paper, and the effect of environments such as temperature, humidity, corrosion from acid, alkaline and salt solutions on durability performance of FRP materials as well as the degradation of the bond characteristics between FRP rods and the interface of concrete caused by the acceleration environment test are mainly discussed. The results indicate that the environmenta lconditionsm entioned above affect FRP rods and bond characteristics between FRP rods and the in terface of concrete.In addition, a relatedmodel predicting the influence on durability of FRP rods in alkaline solutions is given and future study trend on durability of FRP rods is presented

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6

Wang, Hong Tao, Ming Xue, and Ju Hui Cao. "Research on the Durability of Magnesium Phosphate Cement." Advanced Materials Research 168-170 (December 2010): 1864–68. http://dx.doi.org/10.4028/www.scientific.net/amr.168-170.1864.

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The Magnesium phosphate cement was prepared from MgO and NH4H2PO4. The changes of the strength, appearance and hydration products of the magnesium phosphate cement were investigated, which are soaked in sulfuric acid solution, sodium hydroxide solution, sodium sulfate solution and magnesium sulfate solution. Besides, the impermeability and salt frost resistance of magnesium phosphate cement were analyzed. The results show that magnesium phosphate cement has good resistance to sulfate erosion, especially the anti-corrosion ability of magnesium sulfate. However the alkali resistance of the magnesium phosphate cement is poor. Therefore, the magnesium phosphate cements are not appropriate to be used in alkaline environment as cementitious material. The resistance of the magnesium phosphate cement to chemical attack is closely related to the stability of the hydration product MgNH4PO4• 6H2O. The magnesium phosphate cements have good impermeability and salt freezing resistance.

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7

Arnold, Suzan, Sandra Raquel Kunst, Luciane Taís Fuhr, and Cláudia Trindade Oliveira. "RESISTÊNCIA A CORROSÃO EM DIFERENTES TRATAMENTOS DE SUPERFÍCIE SOBRE LIGAS DE ZINCO UTILIZADOS EM METAIS SANITÁRIOS." Revista Tecnologia e Tendências 10, no. 2 (December 20, 2019): 185. http://dx.doi.org/10.25112/rtt.v10i2.1899.

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Entre as ligas não ferrosas, as ligas de zamac são as mais utilizadas para a fundição e vêm sendo aplicadas na substituição de peças de latão, utilizadas industrialmente em metais sanitários. O zamac apresenta propriedades mecânicas semelhantes às do latão, porém com custo inferior. Entretanto, a alta porosidade destas ligas, impede que tratamentos superficiais garantam bom acabamento e resistência à corrosão. Visando melhorar o desempenho, frente à corrosão de peças de zamac, o objetivo do presente trabalho é avaliar o processo de diferentes tratamentos de superfície dos metais sanitários produzidos em zamac. As amostras foram injetadas sobre pressão e submetidas a diferentes tratamentos superficiais (tratamento mecânico, tratamento químico, cobre alcalino, cobre ácido, níquel, cromo). Os corpos de prova foram expostos a um meio agressivo, por meio de nevoa salina a fim de analisar a resistência à corrosão das peças, além de análises de polarização, metalografia e microdureza. Observou-se que a maior incidência de corrosão ocorreu nas partes de injeção e solda da peça, as amostras tratadas com níquel e cromo demonstraram o melhor desemprenho frente a resistência a corrosão.Palavras-chave: Zamac. Metais sanitários. Corrosão.ABSTRACTAmong the non ferrous alloys, zamak are the most used for casting and have been applied to substitute brass parts, industrially utilized in sanitary metals. The zamak presents mechanical properties similar to brass, however with lower cost. Meanwhile, the high porosity of these alloys hinders the superficial treatments ensure good finishing and corrosion resistance. Aiming to improve the performance against corrosion of zamak parts, this work evaluates the process of different superficial treatments of sanitary metals produced with zamak. The samples were injected under pressure and submitted to different superficial treatments (mechanical, chemical, alkaline copper, acid copper, nickel and chromium). The specimens were exposed to an aggressive medium through salt spray test to evaluate the corrosion resistance, and the following analysis: polarization, metallography and microhardness. It was observed that the higher corrosion incidence occurred on the injection and weld regions. The samples treated with nickel and chromium demonstrated better performance of corrosion resistance. Keywords: Zamak. Sanitary materials. Corrosion.

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Krivenko, P. V., І. І. Rudenko, О. P. Konstantynovskyi, and О. V. Boiko. "ENHANCEMENT OF STEEL REINFORCEMENT PROPECTION IN ALKALI-ACTIVATED SLAG CEMENT CONCRETE MIXED WITH SEAWATER." Bulletin of Odessa State Academy of Civil Engineering and Architecture, no. 83 (June 4, 2021): 67–76. http://dx.doi.org/10.31650/2415-377x-2021-83-67-76.

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Modern trends in construction industry in terms of efficient use of raw materials and energy, implying a responsible attitude to environment, predetermine application of alkali-activated slag cement concrete (further, AASC concrete). It’s well-known the increased risk of steel reinforcement corrosion is caused by mixing concretes with seawater, presented by chlorides and sulfates. One of the benefits of AASC concrete is possibility to be mixed with seawater. The aim of this research was the enhancement of AASC concrete’s protective properties, mixed with seawater, to steel reinforcement due to modification by complex of additives (further, CA), including portland cement, calcium aluminate cement and clinoptilolite. Kuzel’s salt (3CaO∙Al2O3∙0,5CaCl2∙0,5SO4∙10H2O) was fixed in hydration products of AASC, modified by proposed CA, after 180 d of hydration. Formation of mentioned salt is due to chemical binding of Cl- and SO42- ions by calcium hydroaluminate 3CaO∙Al2O3∙10H2O, formed by co-acting of Portland cement and calcium aluminate cement during hydration process. Clinoptilolite enhances occlusion function of hydrates presented by alkaline hydro-alumina-silicates. State of steel reinforcement, evaluated according to DSTU B V.2.6-181:2011, confirms the effectiveness of CA in plasticized AASC concrete, mixed with seawater. Mass loss of steel rebars, which were reached from AASC concrete, modified by high-plasticizing additive of sodium lignosulphonate, was in compliance with mandatory requirements (no more than 10 g/m2). This fact is evidence of corrosion absence. Obtained results confirm mitigation of steel reinforcement corrosion risk in plasticized AASC concrete, modified by CA and mixed with seawater. This phenomenon is caused by binding of Cl- and SO42- ions due to chemical adsorption by gel-like phases, chemical binding in Kuzel`s salt as well as their occluding by zeolite-containing admixture and alkaline hydro-alumina-silicates. In addition, increased strength of AASC concrete, while mixing with seawater, is caused by both water-reducing effect of salts of strong acids and densification of artificial stone microstructure under their influence.

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Kaushal, Sujay S., Gene E. Likens, Michael L. Pace, Ryan M. Utz, Shahan Haq, Julia Gorman, and Melissa Grese. "Freshwater salinization syndrome on a continental scale." Proceedings of the National Academy of Sciences 115, no. 4 (January 8, 2018): E574—E583. http://dx.doi.org/10.1073/pnas.1711234115.

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Salt pollution and human-accelerated weathering are shifting the chemical composition of major ions in fresh water and increasing salinization and alkalinization across North America. We propose a concept, the freshwater salinization syndrome, which links salinization and alkalinization processes. This syndrome manifests as concurrent trends in specific conductance, pH, alkalinity, and base cations. Although individual trends can vary in strength, changes in salinization and alkalinization have affected 37% and 90%, respectively, of the drainage area of the contiguous United States over the past century. Across 232 United States Geological Survey (USGS) monitoring sites, 66% of stream and river sites showed a statistical increase in pH, which often began decades before acid rain regulations. The syndrome is most prominent in the densely populated eastern and midwestern United States, where salinity and alkalinity have increased most rapidly. The syndrome is caused by salt pollution (e.g., road deicers, irrigation runoff, sewage, potash), accelerated weathering and soil cation exchange, mining and resource extraction, and the presence of easily weathered minerals used in agriculture (lime) and urbanization (concrete). Increasing salts with strong bases and carbonates elevate acid neutralizing capacity and pH, and increasing sodium from salt pollution eventually displaces base cations on soil exchange sites, which further increases pH and alkalinization. Symptoms of the syndrome can include: infrastructure corrosion, contaminant mobilization, and variations in coastal ocean acidification caused by increasingly alkaline river inputs. Unless regulated and managed, the freshwater salinization syndrome can have significant impacts on ecosystem services such as safe drinking water, contaminant retention, and biodiversity.

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Chernykh, Vera N., Natalia A. Patrusheva, Inna N. Pugacheva, Nadezhda S. Nikulina, and Sergey S. Nikulin. "PROSPECTS FOR USE OF TRIETHANOLAMINE IN PRODUCTION OF SYNTHETIC RUB-BERS." IZVESTIYA VYSSHIKH UCHEBNYKH ZAVEDENII KHIMIYA KHIMICHESKAYA TEKHNOLOGIYA 64, no. 3 (March 22, 2021): 100–106. http://dx.doi.org/10.6060/ivkkt.20216403.6303.

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The paper investigates the possibility of using SKS-30 ARK as a promising coagulant of triethanolamine and its salt in the technology of producing styrene-butadiene rubber. It was found that complete coagulation in the presence of triethanolamine occurs only at high consumption of its acidifying agent (sulfuric acid solution). Otherwise, complete coagulation is not observed. This is due to the fact that aqueous solutions of triethanolamine have an alkaline medium, and in this medium the aggregate stability of latex is greatest. It is noted that an increase in the consumption of triethanolamine in the process of coagulation not only does not increase the yield of rubber crumbs, but also leads to an increase in the consumption of the acidifying agent. It was found that to eliminate this disadvantage, it is possible to use the triethanolamine salt-triethanolamine hydrochloride. This solution was obtained from aqueous solutions of triethanolamine and hydrochloric acid, using homogenization. When triethanolamine hydrochloride is used as a coagulant, the process of separating rubber from latex proceeds by a neutralization mechanism. It was found that it is possible to use triethanolamine hydrochloride as a coagulant in lower dosages than sodium chloride and triethanolamine. It should be noted that the aqueous phase formed during the coagulation process in the presence of triethanolamine hydrochloride can later be returned to production as a solvent in the preparation of aqueous solutions of the acidifying agent and coagulant. At the same time, triethanolamine has anti-corrosion activity, which is a positive point for processes where strong sulfuric acid is used. It is established that the physical and mechanical characteristics of vulcanizates obtained on the basis of rubbers made in the presence of triethanolamine hydrochloride meet the requirements of the standard.

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Shekhanov, Ruslan F. "PROTECTIVE ABILITY OF TIN-NICKEL COATINGS." IZVESTIYA VYSSHIKH UCHEBNYKH ZAVEDENIY KHIMIYA KHIMICHESKAYA TEKHNOLOGIYA 60, no. 10 (November 16, 2017): 75. http://dx.doi.org/10.6060/tcct.20176010.5605.

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The calculation of the corrosion current of the steel – plating allowed us to estimate the protective properties and the porosity of the Tin-Nickel coatings. Measured in 3% NaCl solution the potential of steel electrode covered by tin alloy-Nickel thickness of 5, 10, 15 µm, respectively, has values of -277 mV, -314 mV, -355 mV, and the potential of steel 0.8 KP was 440 mV relative to the standard hydrogen electrode. At a thickness of 15 µm and at the mentioned potential the current density of corrosion for system steel – coating from tin-Nickel oxalate electrolyte was 2.3 µa/cm2, and for the coating from fluoride-chloride electrolyte was 7.5 µA/cm2. Therefore, the protective ability of tin-Nickel coatings obtained from oxalate-sulfate electrolytes is 3 times higher than similar coatings from fluoride-chloride electrolyte. Corrosion tests in salt spray chamber for Sn-Ni coatings obtained from oxalate-ammonium electrolyte confirmed the high corrosion resistance of tin-Nickel coatings when the ratio of the metals in the electrolyte was Ni/Sn = 5/1. The coatings obtained from oxalate electrolytes, distinguished by small size grains, in contrast to the coatings deposited from fluoride-chloride electrolyte. The increase in the microhardness of the coatings contributes a more microcrystalline surface topography of the alloy tin-Nickel deposited from oxalate-sulfate electrolytes, as it was evidenced by the results of crystallographic calculations. The test of specimens for microhardness showed that the samples obtained from oxalate-sulfate electrolytes are a bit harder (255 MPa) than samples obtained from fluoride-chloride electrolyte (245 MPa). The study of the structure of the coatings was performed using scanning electron microscope. SEM data showed that coatings obtained from the fluoride-chloride electrolyte have the pores, whereas poros are practically absent for caotings obtained from oxalate-ammonium. Probably, for these reasons the tin-Nickel coating obtained from oxalate-ammonium electrolyte better resists to corrosion in comparison with similar coating prepared from fluoride-chloride electrolyte. The technological process of depositing tin-nickel alloy from said weakly acid electrolyte is twice as effective and high-speed as compared to alkaline tinning, since the electrochemical equivalent of tin (II) is twice as high as for tin (IV) deposited from the alkaline electrolyte. It has been established that coatings obtained from oxalate-ammonium electrolytes, due to increased polarization during electrodeposition, are finer-grained, corrosion-resistant in comparison with coatings obtained from fluoride-chloride electrolytes. High dissipation ability of oxalate-ammonium electrolytes makes it possible to deposit tin-nickel coatings on composite products. The new technological processes studied in the result of the work made it possible to improve the physical and chemical properties of the coatings, to reduce material costs and to reduce environmental pollutionForcitation:Shekhanov R.F. Protective ability of tin-nickel coatings. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2017. V. 60. N 10. P. 75-81

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Zhu, Ming, Hongfang Ma, Mingjing Wang, Zhihua Wang, and Adel Sharif. "Effects of Cations on Corrosion of Inconel 625 in Molten Chloride Salts." High Temperature Materials and Processes 35, no. 4 (April 1, 2016): 337–45. http://dx.doi.org/10.1515/htmp-2014-0225.

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AbstractHot corrosion of Inconel 625 in sodium chloride, potassium chloride, magnesium chloride, calcium chloride and their mixtures with different compositions is conducted at 900°C to investigate the effects of cations in chloride salts on corrosion behavior of the alloy. XRD, SEM/EDS were used to analyze the compositions, phases, and morphologies of the corrosion products. The results showed that Inconel 625 suffers more severe corrosion in alkaline earth metal chloride molten salts than alkaline metal chloride molten salts. For corrosion in mixture salts, the corrosion rate increased with increasing alkaline earth metal chloride salt content in the mixture. Cations in the chloride molten salts mainly affect the thermal and chemical properties of the salts such as vapor pressure and hydroscopicities, which can affect the basicity of the molten salt. Corrosion of Inconel 625 in alkaline earth metal chloride salts is accelerated with increasing basicity.

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13

Sun, Li, Xiang Qian Mi, and Xin Shou Zhang. "Experimental Study on the Compression Performance of GFRP Bars under Different Corrosion Environment." Applied Mechanics and Materials 71-78 (July 2011): 1711–14. http://dx.doi.org/10.4028/www.scientific.net/amm.71-78.1711.

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Glass fiber reinforced polymer (GFRP) bars were exposed to the solutions of different alkaline and chloride salt concentrations in order to examine the influence of different corrosion environment on the compression performance of GFRP bars. The results showed that the stress strain curves of the GFRP bars could be expressed as lines approximately. The compressive strength and elastic modulus gradually decreased with increasing of the corrosion time, and the decrease was more obvious in alkaline corrosion environment.

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14

Huang, Long, Shan Shan Luo, and Wen Kui Li. "Corrosion Behavior of Al₂O₃ Ceramics in the Acid and Alkaline Solutions." Key Engineering Materials 512-515 (June 2012): 509–12. http://dx.doi.org/10.4028/www.scientific.net/kem.512-515.509.

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Al2O3 materials were used in a very wide range due to its good mechanical properties and relative low manufacture cost. The corrosion resistance of Al2O3 materials in acid, alkaline and sea water solutions gained more and more attention because many application situations are severe and the working life is shorten due to the corrosion. In this paper, the corrosion behavior of Al2O3 based materials in acid and alkaline solutions was studied and effect of corrosion time on the corrosion behavior of Al2O3 materials was investigated. The microstructure of as prepared Al2O3 materials was characterized by SEM. Possible corrosion process and mechanism was discussed in details. The results reveal that the as prepared Al2O3 materials show better corrosion resistance in alkaline solution than in acid solutions. In both acid and alkaline conditions, the corrosion mainly occurs in the grain boundary. Mass loss increased with increasing corrosion time, while the corrosion rate was decreased.

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Liang, Xiaojie, Yajun Wang, Yuekun Li, Wei An, Xinru He, Yanzhen Chen, Zhigang Shi, Jun He, and Ru Wan. "Widely-Targeted Metabolic Profiling in Lyciumbarbarum Fruits under Salt-Alkaline Stress Uncovers Mechanism of Salinity Tolerance." Molecules 27, no. 5 (February 26, 2022): 1564. http://dx.doi.org/10.3390/molecules27051564.

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Wolfberry (Lycium barbarum L.) is an important economic crop widely grown in China. The effects of salt-alkaline stress on metabolites accumulation in the salt-tolerant Ningqi1 wolfberry fruits were evaluated across 12 salt-alkaline stress gradients. The soil pH, Na+, K+, Ca2+, Mg2+, and HCO3− contents decreased at a gradient across the salt-alkaline stress gradients. Based on the widely-targeted metabolomics approach, we identified 457 diverse metabolites, 53% of which were affected by salt-alkaline stress. Remarkably, soil salt-alkaline stress enhanced metabolites accumulation in wolfberry fruits. Amino acids, alkaloids, organic acids, and polyphenols contents increased proportionally across the salt-alkaline stress gradients. In contrast, nucleic acids, lipids, hydroxycinnamoyl derivatives, organic acids and derivatives and vitamins were significantly reduced by high salt-alkaline stress. A total of 13 salt-responsive metabolites represent potential biomarkers for salt-alkaline stress tolerance in wolfberry. Specifically, we found that constant reductions of lipids and chlorogenic acids; up-regulation of abscisic acid and accumulation of polyamines are essential mechanisms for salt-alkaline stress tolerance in Ningqi1. Overall, we provide for the first time some extensive metabolic insights into salt-alkaline stress tolerance and key metabolite biomarkers which may be useful for improving wolfberry tolerance to salt-alkaline stress.

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16

Kaiser, Samiul, and Mohammad Salim Kaiser. "A comparative study of chemical and physical properties of copper and copper alloys affected by acidic, alkaline and saline environments." Journal of Electrochemical Science and Engineering 10, no. 4 (July 12, 2020): 373–84. http://dx.doi.org/10.5599/jese.877.

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Chemical and physical behavior including corrosion performance, thermal conductivity and visual color change of the copper-based alloys brass and bronze have been studied prior and after corrosion in acidic, alkaline and saline media. The concentrations of 0.5 M H2SO4, 0.5 M NaOH and 0.5 M NaCl were used in which copper and copper-alloy samples were immersed and left to corrode at room temperature for 28 days. The experiments were performed prior and after corrosion, using conventional gravimetric measurements accompanied with measurements of thermal conductivity, microstructure and optical properties. The color change of different samples was also studied through tristimulus color parameter (L*, a* and b*) values. It is concluded that the corrosion rate of copper and copper alloys is greater in acidic than in salt and alkaline media. This is due to the extent of disruption of the passive film formed on the surfaces. In the cases of alkaline and salt media, the passive films on the surface remain stable to a large extent. Small increase of thermal conductivity takes place due to formation of a very thin film of oxide and hydroxide bonded to the surface. The environment also affects the color of copper and copper alloys by chemical changes like oxidation and formation of different intermetallics on the surfaces. A microstructural study of experimental materials confirms that corrosion after 28 days results in formation of pores on the surfaces in acidic environment, and passive film that grows thicker on the surfaces in alkaline and saline environments. Aluminum oxide that is more stable than zinc oxide causes better anti-corrosion performance and minimal color variation of bronze compared to brass, especially in acidic environment.

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17

Kamdi, Zakiah, C. Y. Phang, and H. Ahmad. "Corrosion Behavior of WC-Co Cermet Coatings." Materials Science Forum 819 (June 2015): 87–90. http://dx.doi.org/10.4028/www.scientific.net/msf.819.87.

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Metal-ceramic composite or cermet coatings have become popular due to their enhanced wear and corrosion resistance properties. Cermet consists of ceramic particulate embedded in a metallic binder. WC-Co coatings are often used in applications that require wear resistance, but there are many applications in which thermally sprayed coatings have been deposited on components that operate under both abrasive and corrosive condition. Thus, in this study, the corrosion behavior of WC-12wt%Co in different electrolyte has been evaluated. Electrochemical test has been done in three electrolytes namely 0.5 M hydrochloric acid, HCl, 0.5 M sulfuric acid, H2SO4 and 0.5 M sodium hydroxide, NaOH. It is found that corrosion potential of this coating in acidic environment is more positive compares to in alkaline environment. Both in acid and alkaline electrolyte, binder dissolution were preferential. It may be concluded that this coating have higher corrosion resistance in alkaline electrolyte than in acid electrolyte.

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Pei, He Zhong, Pan Huang, Qing Nan Shi, Guo Liang Zhang, and Xue Li. "Research to the Corrosion Resistance of the Alkaline Zinc-Nickel Alloy Plates." Advanced Materials Research 616-618 (December 2012): 1756–61. http://dx.doi.org/10.4028/www.scientific.net/amr.616-618.1756.

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The zinc-nickel alloy coatings were electrodeposited by changing the concentration of the NiSO4 • 6H2O in the plating bath. The scanning electron microscopy (SEM) was used to observe the coating’s surface morphology. The EDS was applied to test the coating’s nickel content. The corrosion resistance was studied by using the Tafel curves, AC impedance spectra and the neutral salt spray test. The results showed that: The coating’s nickel content could reach 12.56% when the NiSO4 • 6H2O concentration was 8g/L in the bath and the coating was very smooth, dense and bright. Its corrosion potential was low and its corrosion reaction resistance was best with red rust time up to 46d, so it had good corrosion resistance. But when the NiSO4 • 6H2O concentration was changed, the coatings’ corrosion resistance would be more or less changed.

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19

Francis, Roger, and Steve Clarke. "Corrosion in Caustic Soda in Mineral Processing Operations." Corrosion 76, no. 7 (May 9, 2020): 707–15. http://dx.doi.org/10.5006/3520.

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Because of the high cost of energy, hydrometallurgy is frequently preferred to smelting to extract metals from ores. Many of these processes involve leaching of the metal with an acid, often sulfuric acid. However, there are some processes that use alkaline leachates, such as sodium hydroxide. Hot alkaline solutions present somewhat different corrosion problems to acidic ones and this paper presents data on the corrosion performance of metals and polymers in hot alkaline solutions. Some case histories from the mineral processing industry are used to demonstrate the importance of correct material selection in these corrosive solutions.

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20

Gul, Salma, Anwar-ul-Haq Ali Shah, and Salma Bilal. "Polyaniline-dodecylbenzenesulfonic acid for corrosion inhibition of stainless steel." Journal of Scientific and Innovative Research 3, no. 5 (October 25, 2014): 519–22. http://dx.doi.org/10.31254/jsir.2014.3509.

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Corrosion behavior of stainless steel was investigated by using highly processable polyanilinedodecylbenzenesulfonic acid (PANI-DBSA) salt. An Electroactivity/redox property of the polymer was investigated by cyclic voltammetry. Conducting salt form of PANI-DBSA was studied by UV-Vis spectroscopy. A solution of PANI-DBSA was drop coated on stainless steel electrode. Corrosion performances of PANI-DBSA coated and un-coated electrodes were investigated in 3% sodium chloride (NaCl) by means of DC corrosion (E Tafel) technique. The results show that PANI coating increased the corrosion resistance of stainless steel in an aggressive sodium chloride medium.

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21

Kamdi, Zakiah, and K. T. Voisey. "Characterization of WC-Co Coatings Corrosion Product by Raman Spectroscopy." Advanced Materials Research 1087 (February 2015): 379–83. http://dx.doi.org/10.4028/www.scientific.net/amr.1087.379.

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In cermet coating such as WC-based coating, the coexisting of ceramic and metal results in micro-galvanic corrosion due to different corrosion potential of each element. In this study, WC-17wt%Co was used. The corrosion behaviour of the coating was evaluated by potentiodynamic test in two different electrolyte which are 0.5 M sulphuric acid and 3% by weight alkaline drilling fluid. This coating shows higher corrosion potential in acid electrolyte compares to in alkaline electrolyte. Clear passivation is seen for both cases. Raman shift is able to detect WO3 and WO3H2O as a corrosion product after corrosion test. Keywords: corrosion, WC, Raman shift

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22

Li, L., C. F. Dong, K. Xiao, J. Z. Yao, and X. G. Li. "Effect of pH on pitting corrosion of stainless steel welds in alkaline salt water." Construction and Building Materials 68 (October 2014): 709–15. http://dx.doi.org/10.1016/j.conbuildmat.2014.06.090.

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23

Narkevičius, A., D. Bučinskienė, M. Samulevičiene, and R. Ramanauskas. "Corrosion Behaviour of Zn Coatings Electrodeposited from Alkaline and Acid Solutions." Transactions of the IMF 81, no. 3 (January 2003): 93–97. http://dx.doi.org/10.1080/00202967.2003.11871506.

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24

Young, Chung Daw, and Jenq Gong Duh. "Corrosion of aluminium nitride substrates in acid, alkaline solutions and water." Journal of Materials Science 30, no. 1 (1995): 185–95. http://dx.doi.org/10.1007/bf00352149.

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25

Vlahova-Vangelova, Dessislava Borislavova, Stefan Georgiev Dragoev, Dessislav Kostadinov Balev, Bahytkul Kajkenovna Assenova, and Kumarbek Junusbekovich Amirhanov. "Quality, Microstructure, and Technological Properties ofSheepMeat Marinated in Three Different Ways." Journal of Food Quality 2017 (2017): 1–10. http://dx.doi.org/10.1155/2017/5631532.

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The objective of this study was to explore the effect of 24 and 48 h alkaline (2% pentasodium tripolyphosphate), acid (2% sodium lactate), and water-oil marinating (water : sun flavor oil = 1 : 1 and 2% salt) as well as brine soaking (2% salt) on microstructure, changes in protein, and lipid fractions and technological properties of sheep (m. Longissimus dorsi). Strong myofibrillar fragmentation after 48 h alkaline marinating was observed. Significant swelling and increasing of spaces between myofibrils were found after 24 h brine soaking. Marinating in water-oil emulsions did not show a significant impact on the muscle microstructure. Alkaline and acid marinating as well as salt soaking promote the myofibrillar protein solubility and increased the free amino nitrogen content. After 24 h acid and 48 h alkaline marinating SDS-PAGE electrophoresis showed increasing of 25–30 kDa protein bands. The results obtained for the lipid and protein oxidation confirm prooxidant action of the sodium lactate (2%) and antioxidant effect of polyphosphates (2%) in marinated sheep.

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26

Xu, Fang, and Shu Zhen Wu. "The RE Compound Using in Corrosion Inhibitor of Copper Alloy." Advanced Materials Research 549 (July 2012): 539–42. http://dx.doi.org/10.4028/www.scientific.net/amr.549.539.

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Based on neutral salt spray test and variance analysis, the RE salt compound using in the corrosion inhibitors of copper alloy has been studied. Synergistic effects among the RE salt, benzotriazole and sulfosalicylic acid were conducted through two orthogonal experiments. The results shows that the passive film has a better corrosion resistance after added RE salt,the synergistic effect is obvious in combined copper corrosion inhibitor.

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27

Milošev, Ingrid, and Peter Rodič. "The Effect of Surface Pretreatment of Aluminum Alloy 7075-T6 on the Subsequent Inhibition by Cerium(III) Acetate in Chloride-Containing Solution." Journal of The Electrochemical Society 169, no. 1 (January 1, 2022): 011504. http://dx.doi.org/10.1149/1945-7111/ac4933.

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The study aimed to investigate the effect of surface pretreatment on the corrosion protection of aluminum alloy 7075-T6 in sodium chloride solution using cerium acetate as a corrosion inhibitor. Different surface pretreatments were tested: (i) mechanical grinding, (ii) mechanical grinding and non-water diamond polishing, (iii) mechanical grinding, alkaline etching with NaOH and acid desmutting, and (iv) mechanical grinding, alkaline cleaning with a commercial SurTec cleaner and acid desmutting. Topography, composition, and morphology of inhibited surface during immersion were investigated using optical microscopy, 3-D profilometry, scanning electron microscopy/energy-dispersive X-ray analysis and Fourier transform infrared spectrometry. The corrosion properties were determined by potentiodynamic measurements and electrochemical impedance spectroscopy in sodium chloride solution without and with the addition of cerium acetate. A change in the composition and morphology of the inhibited surface was noticed as a function of surface pretreatment and immersion time. Appropriate surface treatment resulted in improved protection against localized corrosion even after long-term immersion up to 1 month. Among mechanical pretreatments, polishing gave better results than grinding. Among chemical pretreatments, alkaline cleaning in SurTec/HNO3 was more appropriate as a preceding step to acid desmutting than alkaline etching with NaOH.

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28

Wang, Xiao Hong, Yu Wei, Chun Yun Shao, Yi Jun Shi, Wei Xue, and Jian Feng Zhu. "Study on Corrosion Behavior of the 304 Stainless Steel in the Heavy Oil with High Salt, High Sulfur and High Acid Value." Applied Mechanics and Materials 252 (December 2012): 271–75. http://dx.doi.org/10.4028/www.scientific.net/amm.252.271.

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The uniform corrosion and localized corrosion of 304 stainless steel in heavy oil with high salt, high sulfur and high acid value were researched by weight loss method and electrochemical method. The corrosion morphology of samples with and without corrosion product films and the compositions of the corrosion product films were observed using SEM and EDS. The results show that the 304 stainless steel is inapplicable to the refinery equipment of this heavy oil because of the severe local corrosion even if the uniform corrosion rate is as low as 0.0107mm/a. The salt corrosion and sulfur corrosion occur on the local surface of 304 stainless steel because of the chloride ion formed by hydrolysis of salt in the small emulsifying water. The water soluble iron naphthenate produced by chemical reaction between naphthenic and ferrous sulfides impel the local corrosion of the 304 stainless steel.

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29

Tsai, K. C., J. L. Morris, and D. Cubicciotti. "Corrosion Chemistry of Chromium Carbide in Hot Alkali." Corrosion 41, no. 10 (October 1, 1985): 607–10. http://dx.doi.org/10.5006/1.3582991.

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Abstract The corrosion behavior of Cr23C6 was investigated at elevated temperatures in alkaline solutions. The corrosion reaction of chromium carbide occurs via an electrochemical process. The rate of Cr23C6 dissolution in alkaline solution is rapid compared to that in acid, and its behavior is closely related to that of its metal constituent. Chemical analysis of the corrosion products reveals that CrO4= and CO3= are the two major components, although HCO2− and C2O4= are also formed.

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30

Yang, Gui Rong, Wen Ming Song, Xian Ming Sun, Ying Ma, and Yuan Hao. "The Corrosion Behavior of Ni-P/SiC Composite Coating." Advanced Materials Research 291-294 (July 2011): 215–18. http://dx.doi.org/10.4028/www.scientific.net/amr.291-294.215.

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The Ni-P/SiC composite coating was prepared by chemical deposition technique. The corrosion behavior of electroless Ni-P/SiC composite coating was investigated. The results show that the corrosion resistance of electroless composite coating decreased with the increasing SiC concentration in bath solution. There were some little pores among the composite coating and the pores would increased with the increasing SiC content among the coating, which made the corrosion resistance decreased. The corrosion rate increased with the increasing temperature of corrosion liquid. The corrosion resistance was improved for T gradient electroless Ni-P/SiC composite coating comparing with the single electroless composite coating whether the corrosion solution was acid solution or alkaline solution. The corrosion rate were less than 5 mg/cm2for all specimens in alkaline solution, which indicated that the corrosion resistance of electroless composite coating was better than that in acid solution.

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31

Abd El Rehim, Sayed S., and Essam E. Foad. "Effect of Halide Anions on Anodic Behaviour and Passivation of Copper in Alkaline Media." Collection of Czechoslovak Chemical Communications 61, no. 1 (1996): 85–92. http://dx.doi.org/10.1135/cccc19960085.

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The effect of Cl- and Br- on the anodic behaviour and passivation of copper metal in NaOH solution has been investigated by a potentiodynamic technique complemented with XPS analysis. In halide free solutions, the anodic polarization curves involve three anodic peaks correlated to the electroformation of Cu2O, CuO and Cu(OH)2 on the anode surface. The presence of these species in the passive layer has been confirmed by XPS examination. An addition of the halide anions enhances the peak currents of anodic peaks and tends to rupture the passive layer inducing the pitting corrosion. The critical pitting potentials decrease with rising halide concentration while the alkali concentration has an opposite effect. The accelerating effect of Cl- to pitting corrosion is greater than that of Br-. The pitting corrosion was explained by an instantaneous nucleation and growth of anion salt nuclei. Three cathodic peaks on cyclic voltammetric curve were assigned to the electroreduction of pitting corrosion products, Cu(II) and Cu(I) oxides, respectively.

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32

Qiu, Xing-wu. "Corrosion behavior of Al2CrFeCo CuNiTi high-entropy alloy coating in alkaline solution and salt solution." Results in Physics 12 (March 2019): 1737–41. http://dx.doi.org/10.1016/j.rinp.2019.01.090.

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33

Alvisi, Paulo Pio, and Vanessa de Freitas Cunha Lins. "Acid salt corrosion in a hydrotreatment plant of a petroleum refinery." Engineering Failure Analysis 15, no. 8 (December 2008): 1035–41. http://dx.doi.org/10.1016/j.engfailanal.2007.11.014.

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34

Khaled, K. F., and E. Ebenso. "Cerium salt as green corrosion inhibitor for steel in acid medium." Research on Chemical Intermediates 41, no. 1 (April 4, 2013): 49–62. http://dx.doi.org/10.1007/s11164-013-1167-3.

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35

Gnusin, N. P. "Diffusion of acid and alkaline salt solutions through the Nernst diffusion layer." Russian Journal of Electrochemistry 45, no. 10 (October 2009): 1193–97. http://dx.doi.org/10.1134/s1023193509100139.

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36

Brojanowska, Agnieszka, Konrad Kowalczyk, Dominika Sadłowska, and Jerzy Robert Sobiecki. "Corrosion Properties of Anodically Oxidised and Alkaline Treated Titanium Nitride." Solid State Phenomena 227 (January 2015): 467–70. http://dx.doi.org/10.4028/www.scientific.net/ssp.227.467.

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The article compares the corrosion properties of oxide layers formed on titanium nitride (obtained by means of glow-discharge nitriding) using anodic and plasma oxidation. The corrosion properties are analysed in relation to the surface morphology and microstructure of the layers. The oxidation processes were carried out in phosphoric acid (V) (25wt%) containing Ca2+calcium ions. In this environment, oxide layers were produced using two anode oxidation potentials: 5 V and 9.5 V and two plasma oxidation potentials of 200 V and 600 V. The layers were then subjected to alkaline treatment in concentrated NaOH. The concentration of acid and calcium ions contained in the oxidation solution affected the surface morphology and corrosion properties of the oxide layers obtained after alkaline treatment.

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37

Tian, Zhaohui, Lijun Song, and Xinmin Li. "Effect of Oxidizing Decontamination Process on Corrosion Property of 304L Stainless Steel." International Journal of Corrosion 2019 (August 1, 2019): 1–6. http://dx.doi.org/10.1155/2019/1206098.

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Corrosion behaviors of 304L stainless steel (SS) and 304L SS with oxides film (preoxidation 304L SS) in 1 g/L potassium permanganate solution of various pH values were investigated by using mass loss, electrochemical measurement and scanning electron microscope (SEM) observation. The results showed that mass loss of 304L SS increases with the increase of sodium hydroxide or nitric acid concentration in 1 g/L potassium permanganate solution. The polarization curves of 304L SS in potassium permanganate solution show that passive zones are destroyed more easily in acid potassium permanganate solution than alkaline potassium permanganate solution. The corrosion ability of acid potassium permanganate (NP) decontamination solution used for 304L SS is more aggressive than alkaline potassium permanganate (AP) solution. The oxide film on the surface of preoxidation 304L SS can be removed completely in two oxidation reduction decontamination cycles, oxidizing solution of which comprised 0.4g/L sodium hydroxide and 1g/L potassium permanganate. The 304L SS and preoxidation 304L SS performed alkaline oxidation reduction decontamination of 3 cycles were reoxidation. The micromorphology of reoxidation specimens was similar to preoxidation 304L SS. Therefore the chemical decontamination of alkaline oxidizing and acid reducing steps had no negative effect on corrosion of 304L SS and reoxidation of 304L SS carried out decontamination.

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38

Arai, Masatsugu, and Akiomi Kohno. "Corrosion Behavior of Sintered Silicon Nitride Ceramics in Acid and Alkaline Solutions." Zairyo-to-Kankyo 44, no. 5 (1995): 276–80. http://dx.doi.org/10.3323/jcorr1991.44.276.

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39

Fu, Li-cai, Wen Qin, Jun Yang, Wei-min Liu, and Ling-ping Zhou. "Corrosion−wear behavior of nanocrystalline Fe88Si12 alloy in acid and alkaline solutions." International Journal of Minerals, Metallurgy, and Materials 24, no. 1 (January 2017): 75–82. http://dx.doi.org/10.1007/s12613-017-1380-y.

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40

Xi, J. J., Pei Nian Wu, Jun Zhao, and Wei Wang. "Study on Energy-Saving Mode of High-Quality Anti-Corrosion Micro Arc Oxidation Coatings on Magnesium." Applied Mechanics and Materials 33 (October 2010): 479–82. http://dx.doi.org/10.4028/www.scientific.net/amm.33.479.

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In this paper, micro-arc oxidation process on magnesium alloy anode in three models alkaline solutions are considered under conditions of low power. The excellent morphology of ceramic coating is dense smooth film-like structure of the whole. The phase composition of ceramic coating film is MgO, Al2O3, and a kind of phase composition of the main salt. In the constant current mode in a high frequency of small duty cycle of research methods, the corrosion performance (salt spray test) is successfully developed that achieve 800~ 1000 hours of high quality film, under electric current density less than 1A/dm2.

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41

Saengkiettiyut, Kanokwan, Pranee Rattanawaleedirojn, Adisak Thueploy, Jumpot Wanichsampan, and Yuttanant Boonyongmaneerat. "Study of Microstructure and Corrosion Resistance of Zinc Electrodeposits before and after Black Chromating." Key Engineering Materials 751 (August 2017): 119–24. http://dx.doi.org/10.4028/www.scientific.net/kem.751.119.

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In this work, microstructure and corrosion properties of zinc electroplated steel before and after black chromating was investigated. The test samples were prepared by electrodeposition process, using a commercially-available alkaline electrolyte. Subsequently, the galvanized samples were applied with a black chromate-based passivation layer and a clear top-coat layer. Their microstructures were examined using X-ray diffractometry and scanning electron microscopy. The corrosion resistance of the samples was assessed with the salt spray test, following the ASTM B117, electrochemical impedance spectroscopy (EIS), and potentiodynamic polarization in 5 wt.% NaCl solutions. The study showed that zinc electroplated steels exhibit (110) crystallographic orientation. The passivation and top-coat layers did not affect the microstructure of the zinc layer, and covered uniformly on the zinc layer for all sets of samples. The corrosion resistant results obtained from salt spray testing and electrochemical testing revealed that the microstructure of zinc coatings prepared by using different applied current did not influence on their corrosion resistance markedly. While black passivation followed by top coating provided a significant improvement on corrosion resistance of the coatings.

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42

Todorović, M. R., I. Holclajtner-Antunović, U. B. Mioč, and D. Bajuk-Bogdanović. "Characterization of Insoluble Monovalent K⁺, Tl⁺ and Ag⁺ Salts of 12-Tungstophosphoric Acid." Materials Science Forum 555 (September 2007): 207–12. http://dx.doi.org/10.4028/www.scientific.net/msf.555.207.

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The K3PW12O40, K2.5H0.5PW12O40, K2HPW12O40, KH2PW12O40, Ag3PW12O40 and Tl3PW12O40 salts were synthesized and characterized by thermal analysis, IR and impedance spectroscopy, and SEM. The physicochemical characterization of acid alkaline salts revealed the presence of biphasic mixtures of unreacted heteropoly acid and its neutral salt. The unreacted heteroply acid could be washed away by treating the acid salt with water.

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43

Aminova, E. K., and V. V. Fomina. "Salts of Sulfated Oleic Acid Amides as Acid Corrosion Inhibitors." Chemistry and Technology of Fuels and Oils 625, no. 3 (2021): 36–38. http://dx.doi.org/10.32935/0023-1169-2021-625-3-36-38.

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This work is a continuation in a series of studies on the preparation of acid corrosion inhibitors based on carboxylic acids. A method of synthesis of acid corrosion inhibitors based on oleic acid amides has been developed. Several syntheses have been carried out to increase its inhibitory properties. The substances were obtained in several stages. At the first stage, amino alcohols were added to the ОA, then the resulting compounds were sulfonated with sulfuric acid. To expand the field of various inhibitors, reactions with bases are produced. As a result, salts of sulfated amides of oleic acid synthesized with amino nitrates, sulfuric acid and aqueous solutions of bases were formed. To establish the effectiveness of the compounds obtained, the protective ability in dilute hydrochloric acid was evaluated. It is established that some of the obtained substances exhibit the corresponding properties of inhibitors. In this case, the most effective is the ammonium salt of sulfated diethanolamide oleic acid.

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44

Alfattani, Rami, Mohammed Yunus, Ahmed F. Mohamed, Turki Alamro, and Mohamed K. Hassan. "Assessment of the Corrosion Behavior of Friction-Stir-Welded Dissimilar Aluminum Alloys." Materials 15, no. 1 (December 30, 2021): 260. http://dx.doi.org/10.3390/ma15010260.

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The fuel consumption of high-density automobiles has increased in recent years. Aluminum (Al) alloy is a suitable material for weight reduction in vehicles with high ductility and low weight. To address environmental problems in aircraft and maritime applications, in particular rust development and corrosion, the current study assesses the corrosion behavior during friction stir welding (FSW) of two dissimilar Al alloys (AA6061 and AA8011) in various corrosive conditions using salt spraying and submersion tests. Two acidic solutions and one alkaline solution are used in these tests, which are performed at room temperature. The two specimens (AA6061 and AA8011) and the weld region are suspended in a salt spraying chamber and a 5 wt.% NaCl solution is continually sprayed using the circulation pump for 60 h, with the specimens being weighed every 15 h to determine the corrosion rates. According to the salt spraying data, the weld zone has a higher corrosion resistance than the core components. For twenty-eight days, individual specimens are submerged in 3.5 wt.% HCl + H2O and H2SO4 + H2O solutions and seawater. The weld area specimens exhibit stronger corrosion resistance than the base material specimens, and weight loss in the saltwater medium is lower when compared to the other test solutions, according to the corrosion analysis. The scanning electron microscope (SEM) analysis demonstrates that the base metal AA8011 is considerably corroded on its surface.

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45

Kamdi, Zakiah, and K. T. Voisey. "Corrosion Mechanism of Tungsten Carbide-Based Coatings in Different Aqueous Media." Key Engineering Materials 694 (May 2016): 167–71. http://dx.doi.org/10.4028/www.scientific.net/kem.694.167.

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In cermet coatings with both ceramic and metal present, these can have very different corrosion potentials. Therefore, determination of the corrosion behaviour performance and its mechanism is crucial, especially in very acidic and alkaline environment. A conventional high velocity oxy-fuel (HVOF) tungsten carbide (WC)-Co coatings and a weld overlay tungsten carbide-nickel alloy cermet with carbide size of ~0.3-5 mm and ~50-140 mm respectively are used. Potentiodynamic tests are carried out in acidic and alkaline electrolytes: 0.5 M sulphuric acid, pH 0.45 and bentonite drilling fluid, pH 10.45. The behaviour of both coating types tested were pH dependent. The HVOF coating showed preferential dissolution of the binder in both electrolytes, with material loss being approximately twice as severe in the 0.5 M sulphuric acid compared to the alkaline drilling fluid. For the weld overlay coatings, with the larger carbide particles, the Ni3B phase in the binder was preferentially removed in the acidic electrolyte whereas the Ni rich dendritic phase underwent preferential dissolution in the alkaline environment.

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46

Madkour, Loutfy H., R. M. Issa, and I. M. El-Ghrabawy. "Kinetics of Substituted Bis- and Mono-azo Dyes as Corrosion Inhibitors for Aluminium in Hydrochloric Acid and Sodium Hydroxide Solutions." Journal of Chemical Research 23, no. 7 (July 1999): 408–9. http://dx.doi.org/10.1177/174751989902300702.

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This investigation is designed to apply an advanced kinetic–thermodynamic model on the data obtained from acidic and alkaline corrosion of aluminium using bis- and mono-azo dyes as corrosion inhibitors.

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47

Li, Wenbo, Yingfei Yang, Dongdong Song, Jiran Zhu, and Yi Xie. "Study on Compatibility of Waterborne Surface Treatment Coatings." Journal of Physics: Conference Series 2194, no. 1 (February 1, 2022): 012026. http://dx.doi.org/10.1088/1742-6596/2194/1/012026.

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Abstract the severe corrosion of power grid equipment has always been an important factor affecting the service life of equipment. Rust transfer technology is used to treat the corroded equipment to improve the corrosion resistance of transmission grid cabinet equipment in high temperature and high humidity environment. Taking acid modified acrylic acid as the main component, the composite conversion solution was obtained by adding phosphoric acid and phytic acid. Through the surface morphology, electrochemical test and adhesion test after rust conversion, the universality and corrosion resistance of the rust conversion solution were analyzed; Combined with zinc phosphate primer and zinc rich primer, the effects of rust conversion solution on the adhesion and salt spray corrosion resistance of the two commercial primers were studied. The compound conversion solution has good rust conversion effect on atmospheric corrosion rust layer, salt spray corrosion rust layer and damp heat corrosion rust layer; The corrosion resistance and adhesion of atmospheric corrosion rust layer are obviously improved after being treated with rust conversion solution. The adhesion of zinc phosphate primer and zinc rich primer on rust conversion solution is 2.1 times and 0.8 times higher than that of atmospheric corrosion rust layer without rust conversion, respectively. The compound rust conversion solution has strong universality and can convert atmospheric corrosion, salt spray corrosion and damp heat corrosion rust layers. At the same time, it has good corrosion resistance, which can significantly improve the corrosion potential of the corroded surface and reduce the corrosion current density. In addition, the composite rust conversion solution can significantly improve the adhesion and corrosion resistance of the primer coating.

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48

Kovalchuk, O. Yu, and V. V. Zozulynets. "STUDY OF DEFORMATION PROPERTIES OF ALKALI ACTIVATED CONCRETES USING ACTIVE AGGREGATES." Bulletin of Odessa State Academy of Civil Engineering and Architecture, no. 84 (September 30, 2021): 69–77. http://dx.doi.org/10.31650/2415-377x-2021-84-69-77.

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Abstract. Results of study of deformative properties of fine-grain concrete are shown using slag alkali activated cement and active aggregate, represented by fraction 0-2.5 mm. It had been shown that expansion deformations of concrete specimens, supplying process of alkaline corrosion of aggregate in concrete, directly combined with component composition and conditions of hardening and storing of material. Thus, it was show, that using alkaline component in the state of dry salt (sodium carbonate) shrinkage/expansion deformations are varying in the shorter ranges comparing to alkali activated concrete with the alkaline component represented by soluble glass. Introduction of active mineral admixture represented by metakaolin also leads to the decreasing of deformations comparing to the compositions without such admixture. Different conditions of hardening and storing of the specimens are also influence well on the development of shrinkage deformations. It is shown that drying of specimens with active process of alkaline corrosion of concrete makes it possible to stop development of expansion deformations in concrete. Hydrophobization of the dried specimens make it possible to store for some time linear characteristics of concrete specimens. This opens the possibility to store lifeability and exploitation terms of construction with destructive corrosion processes in concrete without spending significant costs and without canceling of construction exploitation. Hydrophobization of specimens without drying leads to the intensification of structure formation processes and higher rates of development of shrinkage/expansion deformations. That means, that traditional method of protection of concrete constructions (covering of concrete constructions by painting materials) is not able to prevent, but also possible to activate development of destructive processes of alkaline corrosion of concrete, becoming dangerous to be used.

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49

Huang, Dan, You Qing Liu, Yuan Liang, and Xiang Mao. "Isolation and Screening of Salt-Tolerance Lactic Acid Bacteria Strain and Study on its Characteristic Producing Lactic Acid." Advanced Materials Research 881-883 (January 2014): 746–50. http://dx.doi.org/10.4028/www.scientific.net/amr.881-883.746.

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The salt-tolerance lactic acid bacteria strain was isolationed and identified from soy sauce mash. The ability producing lactic acid was studied in different culture conditions. The salt-tolerance lactic acid bacteria strain was isolationed and screened by MRS medium with CaCO3and NaCl gradient plate from soy sauce mash. They were identified according to morphorlogy characters and 16S ribosomal RNA (rRNA) gene sequencing methods. The ability producing lactic acid was studied at different fermentation temperature, NaCl concentration and pH value. The results showed: the strain with superior salt-tolerant was identified asLactobacillus delbrueckii subsp. bulgaricus. Its optimum fermentation temperature was 38°C. When NaCl concentration was 18%, its lactic acid yield could reach 22.68 g/L. It had a better absorbing ability of lactic acid in neutral or slight alkaline condition.

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50

Ismail, I., and M. K. Harun. "ADHESION FAILURE OF RUBBER/METAL COMPOSITES UNDERGOING CORROSION." Rubber Chemistry and Technology 90, no. 3 (July 1, 2017): 455–66. http://dx.doi.org/10.5254/rct.16.83764.

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ABSTRACT Rubber/metal composites are known to be highly durable in a normal atmospheric condition. However, when they are exposed to an aggressive environment such as the marine environment, they tend to fail prematurely. The failure is usually caused by the loss of adhesion of the rubber to metal substrate. The aim of this work is to elucidate the adhesion failure mechanism by using a commercial bonding system for bonded rubber/metal exposed in a marine environment. A simulation study that was carried out through a salt spray test indicated that corrosion of the exposed metal substrates induced the loss of adhesion through cathodic disbonding. Laboratory exposure in alkaline medium, cathodic disbonding, and anodic undermining tests suggested that the hydroxyl ions generated from corrosion reactions contributed to the adhesion failure.

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