Journal articles: 'Alkaline corrosion'

1

Zhang, Jifu, Chunming Deng, Jinbing Song, Changguang Deng, Min Liu, and Mingjiang Dai. "Electrochemical Corrosive Behaviors of Fe-Based Amorphous/ Nanocrystalline Coating on Stainless Steel Prepared by HVOF-Sprayed." Coatings 9, no. 4 (March 29, 2019): 226. http://dx.doi.org/10.3390/coatings9040226.

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In this study, FeCrMnWMoSi amorphous/nanocrystalline coating was prepared on stainless steel by high-velocity oxygen fuel (HVOF) spraying. In order to thoroughly evaluate this novel material, the corrosion behaviors and corrosive film characteristics of the amorphous/nanocrystalline coating in NaCl corrosive media were studied using electrochemical measurement technologies such as potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS). It was found that the corrosion resistance of Fe-based amorphous/nanocrystalline coating could be attributed to the passive film formed, which consisted of Fe, Cr, Mo, and W oxides. pH has an important influence on the corrosion resistance of amorphous/nanocrystalline coating by changing the pitting corrosion mechanism. Under neutral and acidic conditions, the corrosion mechanism of Fe-based amorphous/nanocrystalline coating was mainly local pitting corrosion. However, under strong alkaline conditions, the amorphous/nanocrystalline coating not only had pitting corrosion, but also had the active dissolution of the passive film. Therefore, the anti-corrosion performance of Fe-based amorphous/nanocrystalline coating under alkaline conditions was not as good as neutral and acidic corrosive medium.

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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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Tu, Xiaohui, Jun Quan Liu, Wei Li, and Jun Yi Su. "Corrosion Behavior of Chromium Cast Iron and Steel in Hot Concentrated Alkaline." Materials Science Forum 510-511 (March 2006): 174–77. http://dx.doi.org/10.4028/www.scientific.net/msf.510-511.174.

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Abstract. Hot concentrated alkaline corrosion and wearing corrosion environment exists in alumina metallurgical industry. Iron and steel materials with outstanding alkaline corrosion resistance are strongly demanded for their fabrication equipments. In this paper, corrosion resistance in static hot concentrated alkaline solution of several kinds of martensite chromium cast iron and steel was studied through polarization curves, potential-time curves, weight loss in the corrosion, and corrosive morphology analysis. Experimental results indicated that corrosion processes can be divided into three stages: dissolving of passivating films, exposed surface corrosion, and corrosion beneath the corroded product. Protection effect of the passivating films was transitory, and the corrosion rate during the exposed surface corrosion reached the maximum. Corrosion of the testing materials was composed of active dissolving corrosion of the metal matrix and caustic embrittlement cracking of the matrix, as well as grain boundary corrosion for the cast iron. Dissolving corrosion of the metal matrix was the main cause that induced the weight loss, while severe caustic embrittlement cracking of the metal matrix was disadvantageous. With an increase of the chromium content in the cast iron or steel, active dissolving corrosion of the metal matrix increased. However, the tendency of caustic embrittlement cracking decreased.

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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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Maizelis, Antonina, and Boris Bairachniy. "Corrosion-Electrochemical Behaviour of Low-Alloy Steel in Alkaline Media." Chemistry & Chemical Technology 12, no. 2 (June 25, 2018): 258–62. http://dx.doi.org/10.23939/chcht12.02.258.

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Serebrennikova, I., I. Paramasivam, P. Roy, W. Wei, S. Virtanen, and P. Schmuki. "Steel corrosion in alkaline batteries." Electrochimica Acta 54, no. 22 (September 2009): 5216–22. http://dx.doi.org/10.1016/j.electacta.2009.02.022.

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Grischenko, L. S., N. P. Ivanova, V. G. Matys, and V. A. Ashuyko. "Corrosion resistance of hot-dip galvanized steel in chloride-containing medium." Proceedings of the National Academy of Sciences of Belarus, Chemical Series 54, no. 4 (January 12, 2019): 419–27. http://dx.doi.org/10.29235/1561-8331-2018-54-4-419-427.

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Today, corrosion and corrosion protection of metals are the most important scientific, technical, economic and environmental problems. The effect of additions of sodium molybdate, ammonium metavanadate, a mixture of sodium molybdate and ammonium metavanadate, thiourea and sodium orthophosphate on the corrosive behavior of hot-dip galvanized steel in a neutral and slightly alkaline chloride-containing medium has been studied. The experimental results obtained by weight and electrochemical methods proved sodium molybdate, ammonium metavanadate, a mixture of sodium molybdate and ammonium metavanadate, thiourea and sodium orthophosphate to be corrosion inhibitors that slow down the rate of destruction of hot-dip galvanized steel in a neutral and slightly alkaline chloride-containing medium by 1.5–11 times.

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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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Wang, Tianyu, Yahong Zhao, Baosong Ma, and Cong Zeng. "Durability Study on High-Performance Fiber-Reinforced Mortar under Simulated Wastewater Pipeline Environment." Materials 14, no. 14 (July 6, 2021): 3781. http://dx.doi.org/10.3390/ma14143781.

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The acid–alkaline-inducd corrosive environments inside wastewater concrete pipelines cause concrete structural deterioration and substantial economic losses all over the world. High-performance concrete/mortar (HPC) was designed to have better resistance to corrosive environments, with enhanced service life. However, the durability of HPC in wastewater pipeline environments has rarely been studied. A high-performance mortar mixture (M) reinforced by supplemental materials (including fly ash and silica fume) and polyvinyl alcohol (PVA) fibers, together with a mortar mixture (P) consisting of cement, sand and water with similar mechanical performance, were both designed and exposed to simulated wastewater pipeline environments. The visual appearance, dimensional variation, mass loss, mechanical properties, permeable pore volume, and microstructure of the specimens were measured during the corrosion cycles. More severe deterioration was observed when the alkaline environment was introduced into the corrosion cycles. Test results showed that the M specimens had less permeable pore volume, better dimensional stability, and denser microstructure than the P specimens under acid–alkaline-induced corrosive environments. The mass-loss rates of the M specimens were 66.1–77.2% of the P specimens after 12 corrosion cycles. The compressive strength of the M specimens was 25.5–37.3% higher than the P specimens after 12 cycles under corrosive environments. Hence, the high-performance mortar examined in this study was considered superior to traditional cementitious materials for wastewater pipeline construction and rehabilitation.

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Li, Yan, Yasheng Luo, Songtao Hu, Jianglin Gao, and Chaojie Wang. "Effect of Alkali Seepage Erosion on Physical and Mechanical Properties of Laterite." Advances in Materials Science and Engineering 2021 (October 1, 2021): 1–10. http://dx.doi.org/10.1155/2021/8002984.

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Using a modified permeameter, laterite samples that were corroded and permeated by alkaline solutions at different concentrations for varying amounts of time were subjected to triaxial compression tests, chemical composition analysis, particle composition tests, and microstructure analysis. The results showed that the strength parameters c, φ, and K of the laterite samples that were corroded by alkaline-solution permeation were reduced with increasing corrosion time and alkaline-solution concentration. The alkaline-solution corrosion had a minor effect on the strength parameters n and Rf. The contents of Al2O3 and Fe2O3 in the laterite fluctuated and decreased with increasing alkaline-solution concentration and corrosion time. There were no distinct patterns in the relationships between the SiO2 content and the increases in the alkaline-solution concentration and corrosion time. Due to the corrosion during the alkaline-solution permeation, the content of clay particles increased with increasing time and concentration of the alkaline solution. After the permeation with the alkaline solution, the soil particles became smaller and were arranged in an ordered state. The analysis suggested that the permeation effect of the alkaline solution changed the chemical composition of the laterite and the connecting strength of the soil particles, resulting in changes in its physical and mechanical properties.

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Chen, Yin Juan, Jie Song, Qiang Li, and Dan Yu Jiang. "Dissolution of Fused Magnesia in Alkaline Solution." Advanced Materials Research 177 (December 2010): 346–48. http://dx.doi.org/10.4028/www.scientific.net/amr.177.346.

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This work mainly studied the corrosion and dissolution performance of fused magnesia in alkaline solution . The influences of temperature, time and the concentration of alkaline solution on the weight change and particle morphology of magnesia powder were investigated. The corrosion mechanism and dynamics of the magnesia in alkaline solution were discussed by measuring the weight change and XRD analysis. Above results of dissolution studied of fused magnesia powders in alkaline solution would offer important corrosion information for ceramic bulks.

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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

Yan, Feng Jie, Xing Geng Li, and Xue Gang Wang. "The Corrosion Behavior of Galvanized Steel in Alkaline Soil." Applied Mechanics and Materials 331 (July 2013): 416–20. http://dx.doi.org/10.4028/www.scientific.net/amm.331.416.

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The grounding grid of some substation shows severely corrosion, which affects the safe running of power grid. Galvanized steel is widely used in grounding grid. However, the galvanized steel is easy to corrosion in alkaline soil. In this paper, the corrosion behavior of galvanized steel was studied through accelerated corrosion test of burying specimens in laboratory soils and the corrosion rate was measured by electrochemical test. The corrosion products and corrosion appearance were analyzed by means of SEM, and XRD. The results show that pitting corrosion and localized corrosion were observed on the surface of the galvanized steel, the corrosion products were rough and loose, indicating no protection, the corrosion products of galvanized steel were ZnO,FeO(OH),FeCl3,Zn3O(SO4)2,and ZnSO3·2.50H2O. Electrochemical test show that the corrosion rate of galvanized steel in the later corrosion stage is higher than in the initial corrosion stage.

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Lukjan, Arun, Arsit Iyaruk, and Chumroon Somboon. "Evaluation on Mechanical Deterioration of the Asphalt Mixtures Containing Waste Materials When Exposed to Corrosion Solutions." International Journal of Engineering and Technology Innovation 12, no. 2 (February 22, 2022): 130–44. http://dx.doi.org/10.46604/ijeti.2022.8766.

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This research investigates the effect of corrosion solutions on the mechanical properties of asphalt concrete mixtures. A control asphalt mixture (CM) and five polymer-modified (PM) or filler-modified (FM) mixtures containing waste materials are prepared, namely PM high-density polyethylene plastic (PM-PL), PM crumb rubber (PM-CR), FM Para wood ash (FM-PA), FM palm empty fruit bunch ash (FM-EA), and FM rice husk ash (FM-RA). The experiment is conducted by immersing the mixture specimens in four types of water solutions (i.e., distilled water, alkaline solution, sulfate solution, and acid solution), followed by the splitting tests. Finally, the corrosion resistance factor (fc) is computed to assess the corrosive effect of the corrosion solutions. The results show that the degree of reduction in tensile strength mainly depends on the type of corrosion solutions, type of mixtures, and immersion time. FM-EA provides better resistance under the alkaline and acid solutions, while PM-PL exhibits the greatest fc under the sulfate solution. Among all the mixtures, PM-PL shows the greatest ability in withstanding the corrosion solutions.

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15

Zheng, Yafeng, Gemma Fargas, Elaine Armelin, Olivier Lavigne, and Luis Llanes. "Corrosion-Induced Damage and Residual Strength of WC-Co,Ni Cemented Carbides: Influence of Microstructure and Corrosion Medium." Metals 9, no. 9 (September 19, 2019): 1018. http://dx.doi.org/10.3390/met9091018.

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The corrosion behavior of cemented carbides with binders of different chemical nature (Co and Ni) and carbides with distinct mean grain size (ultrafine and coarse) was studied. The investigation also included corrosion media (acidic and neutral solutions containing chlorides and an alkaline solution) as experimental variables. Immersion tests were performed to induce corrosion damage in a controlled way. Electrochemical parameters were measured together with a detailed inspection of the corroded surfaces. Microstructural influence on the tolerance to corrosion damage was evaluated in terms of residual strength. Results pointed out that corrosion rates were lower in the alkaline solution. In contrast, acidic media led to higher corrosion rates, especially for cemented carbides with Co regardless the influence of carbide mean grain size. Corrosion damage resulted in strength degradation due to the formation of surface corrosion pits in acidic solution. In neutral and alkaline solutions, much less pronounced effects were determined. Focused Ion Beam (FIB)/ Field Emission Scanning Electron Microscopy (FESEM) results revealed differences in corrosion-induced damage scenario. In acidic solution, corrosion starts at binder pool centers and evolves towards binder/WC interfaces. Meanwhile, corrosion in alkaline solution is initially located at binder/WC interfaces, and subsequently expands into the ceramic particles, developing a microcrack network inside this phase.

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Švančárková, Anna, Dagmar Galusková, Aleksandra Ewa Nowicka, Helena Pálková, and Dušan Galusek. "Effect of Corrosive Media on the Chemical and Mechanical Resistance of IPS e.max® CAD Based Li2Si2O5 Glass-Ceramics." Materials 15, no. 1 (January 4, 2022): 365. http://dx.doi.org/10.3390/ma15010365.

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The influence of 4% acetic acid (pH~2.4) and an alkaline solution of NaOH (pH~10) on the corrosion resistance and micromechanical properties of disilicate crystals containing glass-ceramics (LS2-GC’s) is studied. Partially crystallized lithium metasilicate crystal containing glass-ceramics (LS-GC’s) are annealed to fully LS2-GC’s using a one stage and a two-stage heating to induce nucleation. Materials with various chemical and wear resistance are prepared. The content of the crystalline phase in the material annealed in the two-stage process A is 60.0% and increases to 72.2% for the material heated in the one-stage process B. The main elements leached in the acidic medium are lithium and phosphorus, while lithium, silicon, and phosphorus leached into the alkaline environment. Material B exhibits better chemical resistance to the corrosive influence of 4% acetic acid under quasi-dynamic conditions. In the alkaline corrosion medium, silicon is leached from material A faster compared to the material B. After prolonged exposure to acidic or basic environments, both materials show evidence of surface structural changes. A decrease of the sliding wear resistance is observed after corrosion in the acidic environment under dynamic conditions. In both materials, the wear rate increases after corrosion.

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Been, J., and D. Tromans. "Titanium Corrosion in Alkaline Hydrogen Peroxide." CORROSION 56, no. 8 (August 2000): 809–18. http://dx.doi.org/10.5006/1.3280584.

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Al-Suhybani, A. A., Y. H. Sultan, and W. A. Hamid. "Corrosion of aluminium in alkaline solutions." Materialwissenschaft und Werkstofftechnik 22, no. 8 (August 1991): 301–7. http://dx.doi.org/10.1002/mawe.19910220805.

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Adhikari, Saikat, Jiahe Ai, Kurt R. Hebert, K. M. Ho, and C. Z. Wang. "Hydrogen in aluminum during alkaline corrosion." Electrochimica Acta 55, no. 19 (July 2010): 5326–31. http://dx.doi.org/10.1016/j.electacta.2010.04.076.

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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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Valandro, Luciana, Sandra Raquel Kunst, Carolina Dias da Costa, and Cláudia Trindade Oliveira. "INFLUÊNCIA DOS PARÂMETROS DE ELETRODEPOSIÇÃO DE COBRE E NÍQUEL SOBRE O ZAMAC." Revista Tecnologia e Tendências 10, no. 2 (December 20, 2019): 159. http://dx.doi.org/10.25112/rtt.v10i2.1891.

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A camada de cobre alcalino confere proteção ao zamac nos processos químicos posteriores, enquanto que a camada de cobre ácido confere nivelamento bem como a camada de níquel que confere brilho e proteção à peça. Neste sentido, esse trabalho tem por objetivo avaliar a influência dos parâmetros do processo de eletrodeposição das camadas de cobre e níquel na resistência à corrosão do zamac 5. Para tanto, camadas de cobre foram eletrodepositadas em amostras de zamac, com aplicação de 2V por 30 minutos e de 1V por 5 minutos + 2V por 40 minutos. Em cima desses depósitos, camadas de cobre ácido foram eletrodepositadas com aplicação de 2V por 30 minutos. Por último, sobre as camadas de cobre foram eletrodepositadas camadas de níquel com aplicação de 4V por 8 minutos e 4V por 20 minutos. O zamac sem e com revestimentos foi avaliado por Microscopia Eletrônica de Varredura (MEV), e quanto ao desempenho corrosivo por testes eletroquímicos (polarização). Os resultados mostraram que a diferença de tensão aplicada na eletrodeposição (1V e 2V) e o aumento de tempo (5min. e 40 min.), possibilitaram a obtenção de uma camada de cobre alcalino mais homogênea e uniforme e consequentemente mais resistente à corrosão do zamac em relação à camada de cobre alcalino com voltagem e tempo constante (2V por 30 min.). Palavras-chave: Corrosão. Eletrodeposição. Zamac. Cobre. Cristais. Porosidade.ABSTRACTThe alkaline copper layer provides zamac protection for subsequent chemical processes, while the acidic copper layer imparts leveling and the nickel layer imparts luster and protection to the part. In this sense, this work has the objective of evaluating the influence of the parameters of the electrodeposition process of copper and nickel layers on the resistance to the corrosion of zamac 5. For this, copper layers were electrodeposited in zamac samples, applying 2V by 30 minutes and 1V for 5 minutes + 2V for 40 minutes. On top of these deposits, layers of acid copper were electrodeposited with 2V application for 30 minutes. Finally, on the copper layers were electrodeposited layers of nickel with application of 4V for 8 minutes and 4V for 20 minutes. Zamac without and with coatings was evaluated by Scanning Electron Microscopy (SEM), and for the corrosive performance by electrochemical tests (polarization). The results showed that the voltage difference applied in the electrodeposition (1V and 2V) and the increase of time (5min and 40min) allowed to obtain a more homogeneous and uniform alkaline copper layer and consequently more corrosion resistant zamac in relation to the alkaline copper layer with voltage and constant time (2V for 30 min.).Keywords: Corrosion. Electrodeposition. Zamac. Copper. Crystals. Porosity.

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Shen, Chang Bin. "Corrosion Characteristics of Friction Stir Welded AZ31 Magnesium Alloy." Advanced Materials Research 785-786 (September 2013): 97–100. http://dx.doi.org/10.4028/www.scientific.net/amr.785-786.97.

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A comparative evaluation of the corrosion behavior of friction stir welded AZ31 weldments under immersion and electrochemical tests was revealed. Extruded Mg alloy plates of 6 mm thick of AZ31 grade were butt welded using friction stir welding (FSW) process. The specimens were exposed to immersion and polarization environments in order to evaluate their corrosion rates at the corrosive media containing Cl-with different pH values. This research work proves a better corrosion resistance of AZ31 magnesium alloy welds at the alkaline solution than the acidic and the neutral solutions.

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Yu, Zuo, Zhang, Wu, Ning, and Zuo. "Al2O3 Coatings on Zinc for Anti-Corrosion in Alkaline Solution by Electrospinning." Coatings 9, no. 11 (October 23, 2019): 692. http://dx.doi.org/10.3390/coatings9110692.

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The severe corrosion accompanied with hydrogen evolution reaction has become the main obstacle restricting the utilization of zinc as an electrode in alkaline batteries. Al2O3 coating helps control the corrosion of zinc in alkaline solution. Herein, a stable Al2O3 coating is fabricated through facile electrospinning from Al(NO3)3 as an efficient anti-corrosion film on zinc. The electrospinning technique facilitates uniform dispersion of Al2O3 particles, therefore the corrosion inhibition efficiency could be up to 88.5% in this work. The Al2O3 coating prevents direct contact between zinc and the alkaline solution and minimize hydrogen evolution. Further, the effects of the thickness of Al2O3 coating on corrosion behavior of zinc are investigated through hydrogen evolution reaction, Tafel polarization, and impedance test. The results show that the thicker Al2O3 coating possessed better corrosion inhibition efficiency due to the higher corrosion resistance and lower porosity. The 18 μm Al2O3 coating on zinc provides corrosion current density of 60.6 mA/cm2, while the bare zinc substrate delivers as much as 526.3 mA/cm2.This study presents a promising approach for fabricating Al2O3 coating for corrosion-resistant applications.

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Resali, Nor Azrina, Koay Mei Hyie, M. N. Berhan, N. R. Nik Roselina, and Che Murad Mardziah. "Corrosion Behavior of Electrodeposited CoNiFe Nanoparticles Immersed in Different Environments." Applied Mechanics and Materials 607 (July 2014): 33–36. http://dx.doi.org/10.4028/www.scientific.net/amm.607.33.

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Replacement or repair of corrosion damaged equipment is the largest maintenance requirement for the industry. One technique for reducing the corrosion of metals is to coat them with thin layers of less reactive metals or alloys. Unfortunately, most metallic coatings are inherently porous and historically have been of little value as barriers against corrosion. Recently, with the development of new alternative material such as electrodeposited CoNiFe, these problems have largely been overcome. This paper investigated the effects of different aggressive environments on the corrosion behavior of electrodeposited CoNiFe. Interestingly, the mixed morphologies with spherical and dendritic structure were found in the neutral and alkaline environment. This morphology exhibited the smallest particle size with less percentage of oxygen elements. Besides, alkaline environment experienced the slowest corrosion rate due to the mixed morphology. It was found that spherical and dendritic refinement provides higher corrosion resistance. The corrosion rate of the sample prepared in alkaline environment was the lowest compared to the others due to the reduction of particle size.

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Li, Jiang Ting, Xiao Bin Han, San Peng Mao, Gui Tao Zheng, and Jian Ying Yu. "Effect of Chemical Corrosion on Properties of SBS Modified Bitumen for Waterproofing Membranes." Materials Science Forum 1035 (June 22, 2021): 958–65. http://dx.doi.org/10.4028/www.scientific.net/msf.1035.958.

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SBS modified bitumen membrane used in underground engineering and coastal buildings would be corroded by chemical media, which greatly influenced the service life of waterproofing membranes. In this paper, SBS modified bitumen (MB), SBS modified bitumen with stone powder (MBS) and SBS modified bitumen with talc powder (MBT) were corroded by acidic, alkaline, and saline solutions for different time to evaluated the effect of chemical corrosion on the properties of SBS modified bitumen waterproofing membrane. The mass change ratio, low temperature flexibility, softening point and viscosity of SBS modified bitumen were investigated, and Fourier infrared spectroscopy (FTIR) was used to analyze the chemical structural changes of SBS modified bitumen after corrosion. The results showed that the mass of SBS modified bitumen decreased, the low temperature performance decreased, and the softening point increased after corrosion by chemical solutions. The influence of acidic and saline solution was more serious on SBS modified bitumen with fillers, and the properties of MBS has greatest degradation in acidic solution compared with MB and MBT. In alkaline solution, the properties degradation of MBT and MBS was less than that of MB, which indicated that filler could inhibit the alkaline corrosion of SBS modified bitumen. FTIR showed that C=C decreased more in acidic solution, while C=O and S=O of SBS modified bitumen increased significantly after alkaline solution corrosion, which indicated that acidic solution corrosion easily caused SBS degradation, while alkaline solution corrosion was easy to oxidize SBS and bitumen.

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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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Shelontsev, V. A., I. G. Gorichev, A. V. Kuzin, I. V. Gerasimova, and E. A. Eliseeva. "Steel Corrosion Patterns in Neutral and Alkaline Iron Oxide Slurry." Herald of the Bauman Moscow State Technical University. Series Natural Sciences, no. 5 (98) (October 2021): 142–55. http://dx.doi.org/10.18698/1812-3368-2021-5-142-155.

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The study identifies and theoretically substantiates the steel corrosion patterns in aqueous slurry of iron-ore concentrate. The purpose of the study was to examine the effect that the content of dissolved oxygen(PO2), pH, the concentration of chloride ions (CCl-) and the rate of movement of the iron oxide slurry (ω) produce on the corrosion losses of steel 20. Comparative analysis of the corrosion rate values obtained by the gravimetric method and the polarization resistance method showed that the reciprocal of the polarization resistance and the corrosion rate change symbatically with increasing pH, the corrosion rate values are quantitatively well consistent with each other. To identify the corrosion patterns, the method of polarization resistance was used. The dependence of the corrosion rate (ρ) on рН revealed two characteristic areas: in the first one, there is no dependence of the rate on pH (6.5--9.0); in the second one, there is a sharp decrease in corrosion losses when the pH goes from 9.0 to 12.5. For pH = 6.5--9.0, the corrosion rate increases linearly with an increase in the partial pressure of oxygen, and corrosion losses in the slurry are higher than in the background solution. The dependence ρ(√ω) is linear over the entire pH range (6.0--9.0), which indicates the diffusion control of the corrosion process. Findings of research show that in order to protect carbon steel from corrosion in the iron oxide slurry, it is necessary to take into account the pH and О2 concentration. Optimal reduction of corrosion losses can be achieved by alkalizing the slurry and removing dissolved oxygen

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Hassan, Refat, Ishaq Zaafarany, Adil Gobouri, and Hideo Takagi. "A Revisit to the Corrosion Inhibition of Aluminum in Aqueous Alkaline Solutions by Water-Soluble Alginates and Pectates as Anionic Polyelectrolyte Inhibitors." International Journal of Corrosion 2013 (2013): 1–8. http://dx.doi.org/10.1155/2013/508596.

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The corrosion behavior of aluminum (Al) in alkaline media in presence of some natural polymer inhibitors has been reinvestigated. The inhibition action of the tested inhibitors was found to obey both Langmuir and Freundlich isotherms models. The inhibition efficiency was found to increase with increasing the inhibitors concentration and decrease with increasing the temperature, suggesting physical adsorption mechanism. Factors such as the concentration and geometrical structure of the inhibitor, concentration of the corrosive medium, and temperature affecting the corrosion rates were examined. The kinetic parameters were evaluated, and a suitable corrosion mechanism consistent with the kinetic results obtained is suggested and discussed.

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Cao, Zhong Lu, Makoto Hibino, and Hiroki Goda. "Effect of Nitrite Concentration and pH on Steel Corrosion Induced by Sulfate in Simulated Concrete Pore Environment." Applied Mechanics and Materials 368-370 (August 2013): 911–18. http://dx.doi.org/10.4028/www.scientific.net/amm.368-370.911.

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The effect of nitrite on steel corrosion induced by sulfate in three simulated concrete pore environments has been investigated by means of half-cell potential, linear polarization resistance and visual examination, as well as sulfate-induced corrosion is compared with chloride-induced corrosion. The results indicate that with the presence of nitrite, sulfate-induced corrosion can be inhibited effectively. Sulfate threshold level increases with the increasing of nitrite concentration and highly alkaline environment plays an important role in assisting nitrite to inhibit sulfate-induced corrosion. Chloride-induced corrosion is more prone to initiate than sulfate-induced corrosion in highly alkaline environment but in neutral environment, when nitrite content is equal to or less than 0.053mol/L, sulfate-induced corrosion is more likely to occur than chloride-induced corrosion.

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Ismail, W. M. I. W., N. S. W. Zulkefeli, and M. N. Masri. "A Sight of Zinc Corrosion in Various Alkaline Media." Journal of Tropical Resources and Sustainable Science (JTRSS) 4, no. 2 (August 13, 2021): 95–97. http://dx.doi.org/10.47253/jtrss.v4i2.614.

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This review concentrates on corrosion properties that expose to zinc by various alkaline media. The assumption has been advanced that zinc corrodes electrochemically in the first stage of exposition, but the chemical corrosion prevails after a longer time. Different types of electrolyte had been tested on zinc such as sodium chloride, sodium hydroxide and potassium hydroxide. Each of alkaline media can produced corrosion product such as zinc hydroxide chloride, zinc hydroxide carbonate, zinc oxide, and zinc hydroxide. The production of corrosion products is depending on the carbon dioxide content that introduced to the air. Potassium hydroxide is the highest and active alkaline where it contains the highest ionic conductivity potassium ions, K+ after hydronium, H3O+ among the cations and hydroxide, OH ? has the highest ionic conductivity among the anions.

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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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Yuan, Xin Yan, Heng Gen Shen, and Zhen Hua Wang. "Experimental Study on the Properties of Modified PSA Fiber after Corrosion." Advanced Materials Research 183-185 (January 2011): 1631–34. http://dx.doi.org/10.4028/www.scientific.net/amr.183-185.1631.

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In order to improve the reliability of PSA in industrial furnaces corrosion condition, tests are made in different concentration of PTFE emulsion to modify PSA fiber, and experiments are conducted on the comparison of corrosion resistance before and after modification. The results show that: the mechanics properties of PSA fiber decline after the modification with PTFE emulsion, but the corrosion resistance is obviously improved. There will be rising phenomenon of the mechanical properties of the fiber after corrosion treatment by 15% PTFE emulsion initially. The improvement of corrosion resistance of modified PSA fiber has certain relationship with the concentration of PTFE emulsion. In alkaline corrosive environment, the corrosion resistance of modified PSA fiber has a certain proportional relationship to the concentration of PTFE emulsion. In acid corrosive environment, there exists a optimal value of the concentration of PTFE emulsion. The modified effect of the concentration of 5% and 10% PTFE emulsion is better than that of 15%. This shows that the PSA must be dealt against corrosion when used in industrial furnaces with high temperature, high humidity and the corrosion condition. Dipping with PTFE emulsion is a very effective method.

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ZAVERACH, YE M., and O. I. STREMETSKYI. "CORROSION INHIBITORS FOR ALUMINIUM IN ALKALINE MEDIUM." HERALD of Khmelnytskyi national university 271, no. 2 (March 2019): 44–48. http://dx.doi.org/10.31891/2307-5732-2019-271-2-44-48.

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Trivelpiece, Cory L., Jarrett A. Rice, Nicholas L. Clark, Bernd Kabius, Carol M. Jantzen, and Carlo G. Pantano. "Corrosion of ISG fibers in alkaline solutions." Journal of the American Ceramic Society 100, no. 10 (June 15, 2017): 4533–47. http://dx.doi.org/10.1111/jace.14950.

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Liu, Hong Tao, De Kun Zhang, Shou Fan Cao, Yan Shen, Xing Hui Hou, and Lin Min Xu. "Fretting Corrosion Wear Behaviors of Steel Wires in Hoisting Ropes in Alkaline Condition." Applied Mechanics and Materials 99-100 (September 2011): 1014–17. http://dx.doi.org/10.4028/www.scientific.net/amm.99-100.1014.

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In this paper, the fretting corrosion wear behaviors of steel wires were researched when the wires were lubricated with alkaline solution. Then, the wear mechanism was analyzed. Results showed that the friction coefficients of wires lubricated with alkaline solution were little influenced by the loads, while greatly affected by the electrochemical corrosion existing on the surfaces of the friction pairs. The shape of most of the fretting wear debris was tuberous or near spherical which owns smooth edges. This kind of wear debris was beneficial to reduce the fretting wear of steel wires. The depth of wear scar, used to evaluate the fretting corrosion wear of the steel wires, was increased with the increase of load. In addition, the wear depth of the wire lubricated with alkaline solution was not only less than which obtained in dry friction condition, but also less than which lubricated with deionized water and acid solution. Analysis showed that the corrosion solution played an important part in the fretting corrosion wear. And the effect of corrosion solution to the wear was stronger than which to the corrosion of steel wire materials.

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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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Ganiev, I. N., O. Kh Niyezov, N. M. Mulloeva, and B. B. Eshov. "INFLUENCE OF ALKALINE – EARTH METALS ON ANODIC BEHAVIOR OF ALLOY ССУЗ IN NEUTRAL ENVIRONMENT OF THE ELECTROLYTE NaCl." Litiyo i Metallurgiya (FOUNDRY PRODUCTION AND METALLURGY), no. 1 (April 6, 2018): 84–89. http://dx.doi.org/10.21122/1683-6065-2018-1-84-89.

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The anodic behavior of a lead-antimony alloy (3 wt% Sb) doped with alkaline-earth metals was investigated in potentiostatic method in the potentiodynamic mode at a potential sweep rate of 2 mV/s and it was shown that with an increase in the content of alkaline earth metals in the alloy (SSUZ), the potentials of free Corrosion and pitting are slightly shifted to the positive region. As the concentration of the chloride ion in the electrolyte increases, these potentials decrease. The current density of corrosion and, accordingly, the corrosion rate of alloys with an increase in the content of alkaline earth metals are reduced by 75–85%, and the concentration of chloride ion increases.In transition from alloys with calcium to alloys with strontium, the corrosion rate of alloys increases by 20–30%, and to alloys with barium it decreases by 25–30%.

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Cao, Zhong Lu, Makoto Hibino, and Hiroki Goda. "Effect of Nitrite Concentration and pH on Steel Corrosion Induced by Chloride in Simulated Concrete Pore Environment." Applied Mechanics and Materials 193-194 (August 2012): 314–18. http://dx.doi.org/10.4028/www.scientific.net/amm.193-194.314.

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The influence of nitrite concentration on the corrosion of steel immersed in three simulated pH environments that really exist on the surface of steel in concrete has been investigated by comparing and analyzing the change of threshold level of Cl- and NO2-/Cl- mole ratio. The results indicate that with the presence of nitrite, the corrosion of steel can be inhibited effectively. Chloride threshold level increases with the increasing of nitrite concentration and highly alkaline environment plays an important role in assisting nitrite to inhibit corrosion. The use of NO2-/Cl- mole ratio as the parameter to guarantee the inhibition efficiency is suitable in highly alkaline environment, but not appropriate in weakly alkaline and neutral environments.

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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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40

Bautista, Asunción, Francisco Velasco, and Manuel Torres-Carrasco. "Influence of the Alkaline Reserve of Chloride-Contaminated Mortars on the 6-Year Corrosion Behavior of Corrugated UNS S32304 and S32001 Stainless Steels." Metals 9, no. 6 (June 14, 2019): 686. http://dx.doi.org/10.3390/met9060686.

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The durability of two lean corrugated duplex stainless steel (UNS S32304 and S32001) bars manufactured for concrete reinforcement was studied in four different corrosive conditions. These duplex stainless steels are more economical than the most traditional, well-known duplex grade steels (UNS S32205). The research was carried out in mortar samples for six years. In half of the samples, the alkaline reserve had been previously decreased, and their pH was slightly below 12, while in the other half, the pH close to the bars remained as-manufactured. Moreover, there were samples with modified and non-modified alkaline reserve where chlorides had been previously added to the mortar which were exposed to high relative humidity. In other samples—which were partially immersed in 3.5% NaCl—the chlorides entered through the mortar by natural diffusion. The electrochemical behavior of the reinforcements in these conditions was periodically monitored through corrosion potential (Ecorr) and electrochemical impedance spectroscopy (EIS) measurements during the whole testing period. The samples were anodically polarized at the end of the exposure. The results prove that the decrease in the alkaline reserve of the mortars can affect the corrosion behavior of the studied lean duplex in environments with high chloride concentrations. The duplex microstructure of the reinforcements makes it so that the corrosion proceeds by selective attack of the phases.

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Mao, Ji Ze, Hong Wei Zhang, Jian Fu Lv, Dao Guang Jia, and Shi Kai Ao. "Mechanical Properties and Corrosion Mechanism of GFRP Rebar in Alkaline Solution." Key Engineering Materials 665 (September 2015): 217–20. http://dx.doi.org/10.4028/www.scientific.net/kem.665.217.

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Steel corrosion is one of the main problems of concrete structure durability. Compared with the steel, GFRP rebar has the advantages of high strength, low density and good corrosion resistance. Therefore, GFRP becomes a good choice to replace steel bar in concrete structure. Since GFRP material is susceptible to the alkaline conditions, it is necessary to clarify the mechanical properties and corrosion mechanism of GFRP rebar in such an alkaline environment of interior concrete. In this study, the artificial accelerated corrosion tests of two kinds of GFRP rebar (epoxy and unsaturated polyester resin matrix) were conducted at 60 °C in alkaline solution up to 90 days. Then the tensile strength tests of GFRP rebar were carried out. The solution PH values, the tensile strength and mass loss of GFRP rebar were measured. The testing results show that the mass of GFRP rebar had rarely changed, but the tensile strength reduced about 30% after 90-day immersion test in alkaline solution. During the test, the PH value of the alkaline solution decreased from 13.62 to around 12.85, which indicated that the hydroxyl ions of the alkaline solution had been consumed. The ester bonds in resin matrix may hydrolyze in alkaline solution and the bonding interface between fiber and resin can be damaged progressively. It can cause the performance degradation of GFRP rebar. In addition, the relationship between the loss of tensile strength and the reduction of PH can be determined. That means the durability of GFRP rebar in concrete can be enhanced by controlling or limiting the alkalinity when producing concrete. Finally, the GFRP rebar of epoxy resin matrix shows higher retention values of tensile strength and better alkali resistance than those of UPR matrix rebar after 90d immersion in the alkaline solution. The obtained results in this paper can provide application reference of GFRP materials in civil engineering.

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Aggerbeck, Martin, Alexis Herbreteau, Marleen Rombouts, Jo Verwimp, and Rajan Ambat. "Alkaline corrosion properties of laser-clad aluminum/titanium coatings." Anti-Corrosion Methods and Materials 62, no. 1 (January 5, 2015): 37–47. http://dx.doi.org/10.1108/acmm-07-2013-1290.

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Purpose – The purpose of this paper is to study the use of titanium as a protecting element for aluminum in alkaline conditions. Design/methodology/approach – Aluminum coatings containing up to 20 weight per cent Ti6Al4V were produced using laser cladding and were investigated using light optical microscope, scanning electron microscope – energy-dispersive X-ray spectroscopy and X-Ray Diffraction, together with alkaline exposure tests and potentiodynamic measurements at pH 13.5. Findings – Cladding resulted in a heterogeneous solidification microstructure containing an aluminum matrix with supersaturated titanium (<1 weight per cent), Al3Ti intermetallics and large partially undissolved Ti6Al4V particles. Heat treatment lowered the titanium concentration in the aluminum matrix, changed the shape of the Al3Ti precipitates and increased the degree of dissolution of the Ti6Al4V particles. Corrosion testing showed significant localized dissolution of the aluminum matrix. Research limitations/implications – Increased titanium concentration and heat treatment gave improved alkaline corrosion properties. At pH 13.5, the Al3Ti phases were protected, while the aluminum matrix corroded. Practical implications – For alkaline corrosion-protection of aluminum in the automobile industry, titanium might be useful at pH values below 13.5 or by using other coating techniques. Originality/value – This is the first study testing the use of titanium as a protective element of aluminum in stringent alkaline conditions.

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Panja, B., and P. Sahoo. "Tribo-corrosion Behavior of Electroless Ni-P Coatings in Alkaline Corrosive Environment." Portugaliae Electrochimica Acta 32, no. 5 (2014): 303–13. http://dx.doi.org/10.4152/pea.201405303.

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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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Wang, Ying, Hong Ying Yu, Yuan Cheng, Hai Tao Shan, Li Xin Zhang, and Dong Bai Sun. "Corrosion Behaviors of X80 Pipeline Steel in Different Simulated Alkaline Soil Solution." Advanced Materials Research 189-193 (February 2011): 4261–66. http://dx.doi.org/10.4028/www.scientific.net/amr.189-193.4261.

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Corrosion behaviors of X80 pipeline steel were investigated in different simulated alkaline soil solution using electrochemical test, EDS coupled to SEM and weight loss method. The results showed uniform corrosion was happened on X80 steel in Shanshan and Hami simulated solution, and local corrosion was the main failure mode for X80 steel in Yumen simulated solution. The ranking of corrosion rate of X80 steel from the biggest in simulated solution was Hami, Shanshan and Yumen. With the increasing of immersion time, a dense Ca2+ deposited layer was formed on the surface of X80 steel, which could inhibiting the Cl- effects on the corrosion of X80 steel in Shanshan and Hami solution. The SO42- competition absorbed effect could provide certain corrosion protection for X80 steel in Yumen solution at the early corrosion stage.

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Quan, Bian Li, Jun Qi Li, and Chao Yi Chen. "Effect of Additional Sulfide and Thiosulfate on Corrosion of Q235 Carbon Steel in Alkaline Solutions." International Journal of Corrosion 2016 (2016): 1–8. http://dx.doi.org/10.1155/2016/8549312.

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This paper investigated the effect of additional sulfide and thiosulfate on Q235 carbon steel corrosion in alkaline solutions. Weight loss method, scanning electron microscopy (SEM) equipped with EDS, X-ray photoelectron spectroscopy (XPS), and electrochemical measurements were used in this study to show the corrosion behavior and electrochemistry of Q235 carbon steel. Results indicate that the synergistic corrosion rate of Q235 carbon steel in alkaline solution containing sulfide and thiosulfate is larger than that of sulfide and thiosulfate alone, which could be due to redox reaction of sulfide and thiosulfate. The surface cracks and pitting characteristics of the specimens after corrosion were carefully examined and the corrosion products film is flake grains and defective. The main corrosion products of specimen induced by S2−and S2O32-are FeS, FeS2, Fe3O4, and FeOOH. The present study shows that the corrosion mechanism of S2−and S2O32-is different for the corrosion of Q235 carbon steel.

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Assadian, Mahtab, Mohd Hasbullah Idris, Mohammad Mahdi Taheri, Mostafa Rezazadeh Shirdar, and Davood Almasi. "Effects of Alkaline Treatment on Corrosion Behavior of Biodegradable Magnesium." Advanced Materials Research 1125 (October 2015): 441–44. http://dx.doi.org/10.4028/www.scientific.net/amr.1125.441.

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Corrosion behavior of Magnesium substrate were investigated after NaOH treatment in different concentrations (1, 5, and 10 Molar) and duration of (10 min, 30 min, 1 h, 3 h, 6 h and 24 h) at room temperature to be utilized in biomaterial application. Creation of Mg(OH)2 barrier layer after treatment enhanced corrosion resistance. X-Ray diffraction (XRD) was conducted to detect the existence of barrier layer. Potentiodynamic polarization and immersion tests were evaluated the corrosion behavior of Magnesium in Kokubo simulated body fluid (SBF). It is found that Magnesium treated by 1M NaOH for 30 min reveals higher corrosion resistance. In addition this investigation indicates that pH value of Kokubo SBF, strongly influenced by different time and concentration of alkaline treatment

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Zhang, Li Jing, Yi Wei Pan, Gang Tao, Yi Min Wang, and Yuan Li. "Study of Effect and Protection for Corrosion on Buried Pipeline by AC Interference." Advanced Materials Research 557-559 (July 2012): 1756–63. http://dx.doi.org/10.4028/www.scientific.net/amr.557-559.1756.

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Small-scale experiments were conducted to evaluate the corrosion on buried pipeline by AC interference. The results showed that stray current, pH and conductivity are significantly influenced the pipeline corrosion rate according to the response surface methodology (RSM) . The corrosion rate of buried pipeline greatly increased with the increase of stray current. The corrosion rate of most specimens first decreased and then increased slightly with the rise of pH. The corrosion rate of most specimens first decreased and then increased with the rise of conductivity in acid soils, but contrary in neutral and alkaline soils. Most of the specimen surface was covered with different sizes of reddish-brown bumps corrosion products in the acidic solution and reddish-brown, black corrosion products in the alkaline solution, but the specimen surface was smooth in the neutral solution. Because of economic and environmental factors, the AC interference is not always achievable. Therefore, comprehensive approaches should be taken for AC interference protection.

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Shinato, Kebede W., Abraham Amenay Zewde, and Ying Jin. "Corrosion protection of copper and copper alloys in different corrosive medium using environmentally friendly corrosion inhibitors." Corrosion Reviews 38, no. 2 (March 26, 2020): 101–9. http://dx.doi.org/10.1515/corrrev-2019-0105.

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AbstractThe corrosion mechanism of copper and copper alloy is reviewed. A number of scientific papers have been investigated to determine the corrosion mechanism and protection techniques of copper and copper alloy corrosion. Results have shown that copper can be corroded in an acidic or an alkaline environment, and oxide formation is the corrosion initiation process. The use of corrosion inhibitors is one of several ways of controlling metal corrosion. There are inorganic (toxic) and organic (green) corrosion inhibitors invented so far. Nowadays, environmental issue is a concern of several scientists in the world. From the results of recent scientific papers, green corrosion inhibitors can be used for copper corrosion protection and they are both economical and environmentally safe. Furthermore, future researches are needed to determine more efficient, environmentally friendly corrosion inhibitors for copper and copper alloys.

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He, Jun, Lin Chen, and Yanjing Su. "Role of Mn addition on the general corrosion and pitting corrosion behavior of 13Cr stainless steel." Anti-Corrosion Methods and Materials 69, no. 1 (December 13, 2021): 94–103. http://dx.doi.org/10.1108/acmm-10-2021-2555.

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Purpose The purpose of this study is to elucidate the effect of Mn addition on the corrosion behavior of stainless steel. Design/methodology/approach Chronoamperometry, quasi-steady-state polarization and electrochemical impedance spectroscopy were used to investigate the corrosion behavior of Mn added A13Cr-HS sample and original S13Cr samples. In addition, the corrosion product film was characterized by a field emission scanning electron microscope equipped with energy-dispersive spectroscopy and X-ray photoelectron spectroscopy. Findings The A13Cr-HS sample with 8 wt.% Mn addition maintained good general corrosion resistance in both acidic and alkaline solutions compared to the original S13Cr sample. Additionally, the A13Cr-HS sample had good pitting resistance in an alkaline solution containing Cl−, but a weaker resistance in an acidic solution. Originality/value The influence of Mn addition on the formation mechanism of the passive film was systematically analyzed.

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Journal articles on the topic 'Alkaline corrosion'

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