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Hernández, Y., O. Troconis de Rincón, A. Torres, S. Delgado, J. Rodríguez e O. Morón. "Relación entre la velocidad de corrosión de la armadura y el ancho de fisuras en vigas de concreto armado expuestas a ambientes que simulan el medio marino". Revista ALCONPAT 6, n. 3 (30 settembre 2016): 272–83. http://dx.doi.org/10.21041/ra.v6i3.152.
Testo completoAbstract (sommario):
Relación entre la velocidad de corrosión de la armadura y el ancho de fisuras en vigas de concreto armado expuestas a ambientes que simulan el medio marino RESUMENEsta investigación presenta una relación empírica entre la velocidad de corrosión de la armadura y la velocidad de ensanchamiento de fisuras por corrosión del recubrimiento de concreto en vigas, con o sin aplicación de carga. Se evaluaron vigas de concreto armado, expuestas a un proceso de corrosión natural mediante el rociado con solución salina al 3,5 %p/p de NaCl, para acelerar el proceso corrosivo de la armadura, mediante ensayos electroquímicos. El ancho de fisuras se evaluó mensualmente para estimar la relación existente entre éste y la pérdida de sección de la armadura. Los resultados demuestran que existe una relación directa entre la propagación del ancho de fisuras y la velocidad de corrosión, observando fisuras de mayor ancho en vigas cargadas.Palabras clave: corrosion; concreto armado; vigas cargadas; ancho de fisuras. Reinforcement corrosion rate and crack width relationship in concrete beams exposed to simulated marine environment ABSTRACTThis investigation presents an empirical correlation between the rebar corrosion rate and the corrosion-induced crack width propagation rate produced on beam's concrete cover, with or without load application to these beams. Reinforced concrete beams were evaluated, exposed to a natural corrosion process by spraying with 3.5 %w/w NaCl solution, to accelerate the rebar corrosion process, was performed with electrochemical tests. The beams corrosion-cracking evaluation was performed once every month, to determine the relation between crack width and the rebar corrosion loss. The results showed a direct relation between crack width propagation and rebar corrosion rate, showing wider cracks in the loaded beams.Keywords: corrosion; reinforced concrete; loaded beams; crack widths. Relação entre a velocidade de corrosão da armadura e a largura das fissuras em vigas de concreto armado expostas a ambientes que simulam o ambiente marinho RESUMOEsta pesquisa apresenta uma relação empírica entre a taxa de corrosão da armadura e a abertura de fissuras por efeito da corrosão da armadura em vigas de concreto, com ou sem aplicação de carga. Foram avaliadas vigas de concreto armado, expostas a um processo de corrosão natural por pulverização com solução salina a concentração de 3,5% de NaCl, para acelerar o processo de corrosão da armadura, mediante ensaios eletroquímicos. A abertura das fissuras foi avaliada mensalmente para estimar a relação entre ela e a perda de seção da armadura. Os resultados mostram que existe uma relação direta entre a propagação da abertura da fissura e a taxa de corrosão, observando a ocorrência de fissuras de maior abertura nas vigas sob carga.Palavras-chave: corrosão; vigas de concreto armado sob carga; abertura de fissuras.
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Sun, Ji Ku, Zong Jie Cao, De Jian Sun e Yi Chen. "Characteristic of Corrosive Damages about Aircraft Structures in Service". Applied Mechanics and Materials 543-547 (marzo 2014): 316–19. http://dx.doi.org/10.4028/www.scientific.net/amm.543-547.316.
Testo completoAbstract (sommario):
In engineering practices, aircraft structures have been damaged due to the structural corrosion, the corrosive problem of aircrafts needs to call high attentions for researchers because aircraft structures are composed of metals and compound metals. In this paper, corrosion problems and structural reliability of aircraft structures are discussed. Corrosion morphology and mechanism of aircraft structures are analyzed based on metal corrosion theory. The characteristics of the various types of corrosions of aircraft structures have been enumerated. The effect of environments in corrosion process of aircraft structures is studied. The law of corrosion developed at aircraft structural parts or materials is summarized. This research contributes to improving professionals capacity of corrosion prevention and control. It also provides technical support for aircraft maintainers.
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Mahecha-Gómez, Andrey Felipe, Claudia Patricia Mejía-Villagrán e Jhon Jairo Olaya-Flórez. "Aplicación de una metodología mixta para la selección de materiales resistentes a la corrosión en medios ácidos y salinos". Respuestas 20, n. 1 (1 gennaio 2015): 112. http://dx.doi.org/10.22463/0122820x.265.
Testo completoAbstract (sommario):
Objetivo: En este artículo se presenta una metodología mixta de selección de materiales para determinar qué material presenta la mejor relación entre resistencia a la corrosión, propiedades mecánicas y costos. Metodología: El trabajo se llevó a cabo utilizando pruebas potenciodinámicas de extrapolación (Tafel) e impedancia electroquímica (EIS), sometiendo las muestras a medios corrosivos de NaCl (3%) y H2SO4 (5%). Las muestras utilizadas fueron el cerámico Zirconia no sinterizada y los aceros AISI 304L, AISI 316 y AISI 316L. Finalmente se aplicó una metodología de selección de materiales para escoger el material que presenta mejor comportamiento en este tipo de medios. Resultados: Como resultado, para las pruebas de extrapolación Tafel con 5% de ácido sulfúrico (H2SO4), se obtuvo que el acero AISI 316 presenta la corriente de corrosión más baja y una pasivación a mayor potencia. En el medio electrolítico con 3%de NaCl, se observa que los valores de potencial de corrosión más altos se presentan en los aceros inoxidables, evidenciándose una menor velocidad de corrosión en los aceros de la serie 316. Conclusiones: Como resultado se obtuvo que el acero AISI 316 utilizado presenta el mejor comportamiento de resistencia a la corrosión en los medios Medios ácidos y salinos.Abstract Objective: This article presents a mixed materials selection methodology is presented to determine which material has the best balance between corrosion resistance, mechanical properties and costs. Methods: The work was realized using potentiodynamic tests of extrapolation (Tafel) and electrochemical impedance (EIS), subjecting the samples to corrosive media of NaCl (3%) and H2SO4 (5%). The samples used were zirconia, steel AISI 304L, AISI 316 and AISI 316L. Finally a mixed methodology was applied in the materials selection to choose the material that has better comportment in this type of electrolyte. Results: For Tafel extrapolation test with 5% sulfuric acid (H2SO4) was obtained that AISI 316 steel which has the lowest current corrosion and passivation at higher power. In the electrolytic medium with 3 % NaCl, shows that higher values for corrosion potential present in stainless steels, showing a lower corrosion rate in the steels of the 316 series. Conclusions: The results showed that steel AISI 316 used presents the best performance to corrosion resistance in saline and acid.Palabras claves: Corrosión, Medios ácidos y salinos, Metodología mixta, Selección de materiales.
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Yu, Zhu Huan, Jun Feng Qiang e Hui Lu Li. "Electrochemical Corrosion Behavior of Different Graphite Shapes Cast Irons in Acidic Solution". Advanced Materials Research 906 (aprile 2014): 275–82. http://dx.doi.org/10.4028/www.scientific.net/amr.906.275.
Testo completoAbstract (sommario):
The effect of graphite shapes on the electrochemical corrosion behavior of cast iron was studied by means of weight loss tests, electrochemical measurements and electron microscopy. It was found that the electrochemical corrosion behavior of graphite is significantly different from one other, and the corrosive potential difference between carbide ad the matrix is the main driving force of the different phase corrosions. Among them, the center A type and edge D type graphite exhibited the highest corrosion resistance. The corrosion of white iron is worst, because there are so many type carbides in white iron and so there is an obvious tendency to produce micro-cell in white iron.
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Sun, Qi Lei, Li Zhang, Jie Dong e Lu Hua He. "Study on Electrochemical Behavior of Prestressed Reinforcement in Simulated Concrete Solution". Applied Mechanics and Materials 357-360 (agosto 2013): 917–20. http://dx.doi.org/10.4028/www.scientific.net/amm.357-360.917.
Testo completoAbstract (sommario):
Using electrochemical impedance spectroscop (EIS) and polarization curve technique, the electrochemical behavior of prestressed reinforcement under different stress levels was studied in simulated concrete solution. The results show that: As the stress increasing, the impedance spectroscopy changes significantly, the entire impedance spectroscopy shows an elongated semi-circular deformation, high-frequency capacitance arc radius corrosion decreases with the corrosion progress, in other words, the reaction resistance decreases, the corrosion rate of the sample increases. And when the galvanized steel is in 1064MPa stresss condition, corrosion current density reaches the maximum, is 9 times larger than that of none stress corrosions condition. Under the combined effects of the external stress and corrosive media, dislocation can be emitted, value-added and moves. When it reached a critical state, it would lead to the crack nucleation of Stress corrosion cracking (SCC).
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Meneses, R. S., J. M. Moro, R. R. Aveldaño e N. F. Ortega. "Influencia del espesor del recubrimiento de elementos de hormigón armado expuestos a procesos de corrosión y sometidos a cargas externas". Revista ALCONPAT 6, n. 2 (31 maggio 2016): 129–44. http://dx.doi.org/10.21041/ra.v6i2.134.
Testo completoAbstract (sommario):
Influencia del espesor del recubrimiento de elementos de hormigón armado expuestos a procesos de corrosión y sometidos a cargas externasRESUMENAl realizar estudios sobre corrosión en hormigón armado, es importante considerar en los ensayos, la acción de cargas externas, pues esta situación es la más frecuente en las estructuras. En este trabajo, se presentan los resultados obtenidos al exponer a un proceso de corrosión acelerada, a vigas de hormigón armado sometidas a esfuerzos flexionales, materializados con cargas, que generan iguales tensiones de tracción en las armaduras corroídas. Las vigas se fabricaron con diferentes espesores de recubrimiento de las armaduras y con un hormigón de resistencia característica 25 MPa. Este estudio pone en evidencia la influencia del espesor de recubrimiento de las armaduras, sobre el proceso de corrosión y su manifestación externa (fisuración del recubrimiento), frente a las mismas solicitaciones mecánicas.Palabras claves: corrosión de armaduras traccionadas; recubrimiento; fisuración. Influence of the thickness of the coating of the elements of reinforced concrete exposed to corrosion processes and subjected to external loadsABSTRACTWhen studies are done in reinforced concrete, it is important to consider the action of external loads, since that is the most common situation in structures. In this study we present the results of exposing reinforced concrete beams to a process of accelerated corrosion, while under bending stresses caused by loads that generate equal tensile stresses on the corroded reinforcements. The beams were built with different cover thicknesses over the reinforcements, and with a 25 MPa characteristic resistance concrete. This study shows the influence of the cover thickness over the corrosion process and its external manifestation (cover cracking), under the same mechanical stress.Keywords: tension corrosion reinforcement; cover; cracking. Influência da espessura de cobrimento dos elementos de concreto armado expostos a processos de corrosão e submetidos a cargas externasRESUMOAo realizar estudos sobre corrosão em concreto armado, é importante considerar nos ensaios a ação de cargas externas, pois esta situação é mais frequente nas estruturas. Neste artigo apresentam-se os resultados obtidos ao expor vigas de concreto armado a um processo de corrosão acelerada, submetidas a esforços de flexão materializados com cargas que geram tensões constantes de tração nas armaduras corroídas. As vigas foram elaboradas com diferentes espessuras de cobrimento das armaduras e com um concreto de resistência característica de 25MPa. Este estudo coloca em evidência a influência da espessura de cobrimento das armaduras, sobre o processo de corrosão e sua manifestação externa (fissuração do cobrimento), frente às mesmas solicitações mecânicas.Palavras-chave: corrosão de armaduras tracionadas; cobrimento; fissuração.
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Heo, Chang-Jae, Min-Gyun Ha, Chanhyun Park e Jin-Hee Ahn. "Comparing Corrosion Damage Level and Corrosion Current in Acceleration Corrosion Testing under Corrosive Environment". Journal of the Korean Society of Hazard Mitigation 23, n. 5 (31 ottobre 2023): 115–22. http://dx.doi.org/10.9798/kosham.2023.23.5.115.
Testo completoAbstract (sommario):
This study conducted an acceleration corrosion test based on ASTM G85-19 standards to evaluate the durability of both steel and paint-coating. The objective was to assess the relative corrosive deterioration based on variations in the corrosive environment. In the ASTM G85-19 test method, we systematically altered the concentration of chloride and (NH<sub>4</sub>)<sub>2</sub>SO<sub>4</sub> to simulate different corrosive environmental conditions. The mean corrosion depth of the steel specimens was determined by quantifying weight throughout the acceleration cycle. Additionally, we measured the corrosion current output using the ACM sensor to validate the corrosive environmental condition corresponding to different acceleration cycle scenarios. Analysis of the results from the acceleration corrosion test revealed significant variations. The mean corrosion depth exhibited a range of 1.1 to 2.7-fold change, while the corrosion current showed fluctuations ranging from 1.2 to 5.7 times, contingent upon the conditions of the acceleration test, including the quantities of chloride and (NH<sub>4</sub>)<sub>2</sub>SO<sub>4</sub> present.
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Yang, Yanpeng, Xiaojuan Cao, Yang Li, Zhongchi Wang, Bingjie Li, Xudong Jiang, Junji Jia e Chunxu Pan. "Spontaneous Symmetry-Breaking in the Corrosion Transformation of Ancient Bronzes". Minerals 10, n. 8 (24 luglio 2020): 656. http://dx.doi.org/10.3390/min10080656.
Testo completoAbstract (sommario):
In general, during long-term museum conservation, ancient bronzes will generate new corrosion products also called the “secondary corrosion” on the surface of the unearthed “primary corrosion” products due to various environmental conditions. In this paper, the corrosion stages of several ancient Chinese bronzes are characterized by using optical microscope (OM), scanning electron microscope (SEM), energy dispersive spectrometer (EDS), X-ray diffraction (XRD) and Raman spectrometer (Raman). It is found that there exist phase transformation relationships in between the “primary corrosion” and the “secondary corrosion” stages (i.e., (1) the crystal lattice type tends to transform from a high symmetry system to a low symmetry system; (2) in case of the same crystal lattice type, the corrosions exhibit an inter-transformation or symbiosis). It is interesting to note that these transformation rules are very consistent with the well-known physical law of “spontaneous symmetry-breaking”, which won the 2008 Nobel Prize in Physics and also has been considered to be general law of nature, in addition to the principle of Gibbs free energy reduction. The significance of this discovery allows us to achieve the predictability and controllability of the bronze corrosion products (i.e., to predict the corrosive trends in advance and control the “second corrosion” by adjusting the conservation conditions. This research provides a novel conservation concept of ancient bronzes.
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Cong, Shen, Ke Tong, Dong Feng Li, Zhi Xin Chen e Ke Cai. "Leakage Failure Analysis of the ERW Steel Pipeline". Materials Science Forum 993 (maggio 2020): 1224–29. http://dx.doi.org/10.4028/www.scientific.net/msf.993.1224.
Testo completoAbstract (sommario):
This paper provides a thorough investigation on the leakage reason of the ERW steel pipeline in an oil field. Through appearance inspection, physicochemical inspection, metallographic inspection and scanning electron microscope (SEM), it was found that the main reason of corrosions was caused by residual liquid at the bottom of the pipeline and O2 and CO2 in the air pressure test. The corrosion medium was large volume of O2 and CO2 forming continuously saturated corrosive aqueous solution in small volume of residual liquid, and the corrosion type was the under-deposit corrosion. It is recommended to conduct hot air purging on the pipelined before pressure test for building pipelines in the future, and if the pipeline is not put into use in time, it is recommended to use nitrogen to maintain pressure.
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Mao, Jincheng, Difei Han, Jinzhou Zhao, Xiaojiang Yang, Chong Lin e Heng Zhang. "Experimental and Theoretical Study on Cyanuric Chloride Derivatives as Corrosion Inhibitors for Oxyen Corrosion of Mild Steel in High Salinity Corrosive Medium". Revista de Chimie 72, n. 2 (7 maggio 2021): 119–36. http://dx.doi.org/10.37358/rc.21.2.8425.
Testo completoAbstract (sommario):
Designed and synthesized two corrosion inhibitors that can resist corrosion of low-carbon steel in high-salinity corrosive media. When these compounds are used as corrosion inhibitors in high salinity corrosive media, the laboratory evaluation results clearly showed that the two corrosion inhibitors had an excellent corrosion resistance. The synthetic corrosion inhibitors have an symmetrical structure which not only has a symmetrical appearance but also has the practical significance of forming an entire surface covering layer, which avoids the general corrosion and pitting corrosion.
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Zhang, Ye Qin, Li Chun Qi e Yi Sheng Huang. "Anticorrosion Property of TC27 Titanium Alloys and Application Evaluation in Tubing". Materials Science Forum 1035 (22 giugno 2021): 615–23. http://dx.doi.org/10.4028/www.scientific.net/msf.1035.615.
Testo completoAbstract (sommario):
In view of the combined effect of the load and the corrosive environment on the downhole tubing and the need for the selection of downhole tubing materials, the study on the pitting corrosion, crevice corrosion, erosion corrosion, high temperature and high pressure simulation of corrosion, galvanic corrosion, resistance to sulfide stress corrosion cracking SSC, resistance to hydrogen induced cracking, stress corrosion cracking test under simulated working conditions for TC27 titanium alloy was carried out. Furthermore, the corrosion performance was evaluated by the test results and evaluation standards such as GB/T 18590-2001, SY/T 7394-2017, GB/T 15748-2013. The results show that TC27 have excellent resistance to pitting corrosion, crevice corrosion and erosion corrosion under the corrosive environment of NaCl and H2S. The alloy also has excellent corrosion resistance and crack resistance under high-intensity environments such as high temperature and high pressure, and has good overall performance, which can effectively meet the needs of anti-corrosion performance of downhole tubing materials in different corrosive environments.
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Ryu, Hwa Sung, e Han Seung Lee. "Study on the Anti- Corrosion Properties of Organic and Inorganic Inhibitor by Electrochemical Treatment in Aqueous Solution". Advanced Materials Research 415-417 (dicembre 2011): 2070–73. http://dx.doi.org/10.4028/www.scientific.net/amr.415-417.2070.
Testo completoAbstract (sommario):
The various methods for improving chloride penetration resistance in the reinforced concrete have been developed. Among the related general ways, using of corrosion inhibitor became very common. Therefore, in this study, in order to comprehend performance of corrosion inhibitor, the experiment study was conducted about corrosion characteristic of 3 steps(0.0, norm 1/2, norm) compared to organic corrosion inhibitor standard use of liquid and molar 3 steps(0.0, 0.3, 0.6%) of Chloride by added amount of inorganic corrosion inhibitor by the corrosion inhibitor types about 2.4kg/m3, 4.8kg/m3based on Chloride ion content 1.2kg/m3for service life prediction of concrete structure by using Poteniostat. As results, in the case of inorganic nitrous acid corrosion inhibitor, it was confirmed that anti-corrosive performance of Chloride ion content 1.2kg/m3by corrosion Ecorr -0.30V in more than molar ratio 0.3%, and it also was confirmed that anti-corrosive performance of 2.4kg/m3, 4.8kg/m3in more than molar ratio 0.6%. In addition, the excellent anti-corrosive performance of organic corrosion inhibitor was shown in 1/2(0.42kg/m3) of norm regardless of Chloride ion content, and it can be seen that absorption types organic corrosion inhibitor has excellent anti-corrosive performance compared to the inorganic nitrous acid corrosion inhibitor by the added amount of corrosion inhibitor.
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Sheashea, M., B. Zagloul, M. Zorainy, I. Naeem e M. Gobara. "Corrosion Resistance Improvement of Mild Steel". Journal of Physics: Conference Series 2830, n. 1 (1 settembre 2024): 012002. http://dx.doi.org/10.1088/1742-6596/2830/1/012002.
Testo completoAbstract (sommario):
Abstract Corrosion’s devastating consequences have become a big issue all over the world. One of the corrosion damage aspects are related to decontamination solutions which are essential for rapid degradation of toxic agents. The decontamination solutions should be non-corrosive to avoid deterioration of steel container. Decontamination solutions comprising have high chlorinating activity so they have a corrosive effect on mild which are used in fabrication of storage tanks. In this case, using inhibitors is one of the most effective strategies to limit the rate of corrosion. This work describes the effect of different compounds; (zinc chromate, cinnamaldehyde, sodium tripolyphosphate, zinc ortho-phosphate, ammonium molybdate and thiourea) on the rate of corrosion of mild steel within dichloroisocyanuric acid decontamination solution. Meanwhile, these inhibitors should not affect active chlorine content which is responsible for the decontamination process. By using kelthoff and AquaChec® methods for measuring active chlorine, it was found that only zinc chromate passed the tests. For measuring electrochemical behaviour of mild steel in decontamination solutions, different techniques were used. Zinc chromate inhibition on mild steel in a 0.5% dichloroisocyanuric acid solution at different temperatures (298–313 K) were studied utilising electrochemical impedance spectroscopy, weight loss, and potentiodynamic polarisation. The results reveal that zinc chromate is an excellent mild steel corrosion inhibitor in dichloroisocyanuric acid, with an inhibition efficacy of 96% at a concentration of 0.005 M. Finally, surface morphology of mild was also investigated using SEM.
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P, Roshith, e Arivarasu M. "Improvements on hot corrosion behaviour of HVOF coated CO2 laser beam and pulsed gas tungsten arc weldments in 2.5% sulphur gas plus molten salt in industrial waste incinerator environment". Engineering Research Express 4, n. 2 (4 aprile 2022): 025003. http://dx.doi.org/10.1088/2631-8695/ac5ebd.
Testo completoAbstract (sommario):
Abstract This research article discusses in detail how the rate of corrosion increases for the Alloy 254 in the molten salt mixture of 10 wt% NaCl + 40 wt% K2SO4 + 40 wt% Na2SO4 + 10 wt% KCl and corrosive gas combination of 2.5% SO2 + 3% O2 + 25% CO2 + 69.5% N2 in simulated municipal solid waste incinerator environment at 700 °C and 800 °C. In addition, the article shows rate of thermal corrosion abridged due to the addition of 80 Ni- 20 Cr -High-velocity oxygen fuel coating on the SMO 254 specimen. Thermogravimetric analysis is adapted to analyze the corrosion rate. A higher hardness was obtained for the High-velocity oxygen fuel coated specimen than that of base metal. Surface roughness was measured on the thermal barrier coated surface. As a result of the impact of molten salt and corrosive gas, hot corrosion by-products such as sulphides, chlorides and Na are produced, which are observed to increase the severity of corrosion rate. The study provides a detailed analysis of the metallurgical changes along the cross-section on the hot corroded samples by optical and Scanning electron microstructural image analysis. X-ray diffraction analysis was used to know about the corrosion products formed during corrosion. Formation of the major protective oxide phases such as NiCr2O4, Cr2O3, NiO and CrMnO4 provide better corrosion resistance to the substrate in the coated samples. The diffusion of the corrosive elements along the cross-section of the weld interface, weld zone, and base metal zone was analyzed in detail using Electron dispersive spectroscopy data in the point scan, line scan, and x-ray mapping techniques. Thermal spray coatings were found to be effective to prevent the hot corrosion, however, a higher weight gain (17.75 mg cm−2) was observed on the pulse current gas tungsten arc weldment sample in the simulated environment compared to a weight gain (2.66 mg cm−2) base metal specimen at 700 °C. Spallation of coated surface occurred at 800 °C, and it could be concluded that the coating has found to be effective in preventing the hot corrosion and safe to operate at a temperature of 700 °C for Alloy 254 in this aggressive simulated environment.
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Journal, Baghdad Science. "Some Non-destructive Testing for Al metal in 0.1N of NaCl and NaOH". Baghdad Science Journal 8, n. 4 (4 dicembre 2011): 988–95. http://dx.doi.org/10.21123/bsj.8.4.988-995.
Testo completoAbstract (sommario):
In this work the corrosion behavior of Al metal was studied by using non- destructive testing (NDT), which is a noninvasive technique for determining the integrity of a material. The ultrasonic waves was used to measure the corrosion which occur by two corrosive medium (0.1N sodium chloride and 0.1N sodium hydroxide) and study the corrosion by weight-loss method and electrochemical method in addition to performance the microscopic inspection for the samples before and after the immersion in the corrosive medium. Corrosion parameters were interpreted in these media which involve corrosion potential (Ecorr) and corrosion current density (icorr). The results indicate that both media was corrosive but the 0.1N NaOH was more corrosive than 0.1N NaCI. Micro hardness test indicates that, the hardness value of the testing metal is decrease in 0.1N NaOH solution more than 0.1N NaCl solution with longest time of immersion.
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Fan, Yu Guang, Zai Dong Piao, Bing Chen e San Pin Zhou. "The Analysis of the Corrosion Parameters' Sensitivity of the Fractionator Overhead Recycle System". Advanced Materials Research 590 (novembre 2012): 91–94. http://dx.doi.org/10.4028/www.scientific.net/amr.590.91.
Testo completoAbstract (sommario):
The relation model established by artificial neural network that includes 4 corrosive material parameters that are Cl-, H2S, NH3 and pH value and corrosion testing parameter that is Fe2+ of the fractionator overhead recycle system, studied the corrosion sensitivity of the corrosion parameters, has got the sensitive areas, put forward the suitable range of the corrosive material parameters of corrosion control in the production process.
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Zhang, Jifu, Chunming Deng, Jinbing Song, Changguang Deng, Min Liu e Mingjiang Dai. "Electrochemical Corrosive Behaviors of Fe-Based Amorphous/ Nanocrystalline Coating on Stainless Steel Prepared by HVOF-Sprayed". Coatings 9, n. 4 (29 marzo 2019): 226. http://dx.doi.org/10.3390/coatings9040226.
Testo completoAbstract (sommario):
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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Wang, Ping, Zhao Hui Yin, Han Tao Ren, Song Xu e Dong Wei Ma. "Review of Copper Atmospheric Corrosion in H2S". Applied Mechanics and Materials 548-549 (aprile 2014): 177–81. http://dx.doi.org/10.4028/www.scientific.net/amm.548-549.177.
Testo completoAbstract (sommario):
The losses due to copper corrosion in H2S atmospheric corrosion have attracted much focus. It’s important to improve copper corrosion resistance that the corrosion law, corrosion mechanism and characteristics were studied in H2S environment. This paper reviewed the corrosion behavior of copper, analyzed the impact of environment factors and corrosion analysis tools. Through evaluating and improving corrosion by external factors, including improving corrosive environment, using coating protection and adding corrosion inhibitors, appropriate corrosion measures were taken to extend the life of the equipment.
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Ahmed, Muhammad, Muhammad Shahid, Zulfiqar Khan, Ameen Ammar, Abdul Saboor, Amir Khalid, Asad Hayat, Adil Saeed e Mehran Koohgilani. "Electrochemical Comparison of SAN/PANI/FLG and ZnO/GO Coated Cast Iron Subject to Corrosive Environments". Materials 11, n. 11 (11 novembre 2018): 2239. http://dx.doi.org/10.3390/ma11112239.
Testo completoAbstract (sommario):
ZnO/GO (Graphene Oxide) and SAN (Styrene Acrylonitrile)/PANI (Polyaniline)/FLG (Few Layers Graphene) nanocomposite coatings were produced by solution casting and sol-gel methods, respectively, to enhance corrosion resistance of ferrous based materials. Corrosive seawater and ‘produced crude oil water’ environments were selected as electrolytes for this study. Impedance and coating capacitance values obtained from Electrochemical Impedance Spectroscopy (EIS) Alternating Current (AC technique) showed enhanced corrosion resistance of nanocomposites coatings in the corrosive environments. Tafel scan Direct Current (DC technique) was used to find the corrosion rate of nanocomposite coating. SAN/PANI/FLG coating reduced the corrosion of bare metal up to 90% in seawater whereas ZnO/GO suppressed the corrosion up to 75% having the impedance value of 100 Ω. In produced water of crude oil, SAN/PANI/FLG reduced the corrosion up to 95% while ZnO/GO suppressed the corrosion up to 10%. Hybrid composites of SAN/PANI/FLG coatings have demonstrated better performances compared to ZnO/GO in the corrosive environments under investigation. This study provides fabrication of state-of-the-art novel anti corrosive nanocomposite coatings for a wide range of industrial applications. Reduced corrosion will result in increased service lifetime, durability and reliability of components and system and will in turn lead to significant cost savings.
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Wang, Kui, Zhanqiang Li e Mingjie Zhao. "Mechanism of Localized Corrosion of Steel Pipe Pile Foundation for Offshore Wind Turbines and Corrosive Action". Open Civil Engineering Journal 10, n. 1 (31 ottobre 2016): 685–94. http://dx.doi.org/10.2174/1874149501610010685.
Testo completoAbstract (sommario):
The wind turbine foundation serves as a permanent construction in the harsh marine corrosive environment, its anti-corrosion design is essential to the safe use of the wind turbine structure. At present, there is a significant controversy over the local corrosion mechanism (such as pitting corrosion, and crevice corrosion) and its diffusion mechanism in the academic circle. In the paper, the Faraday electrochemistry formula was used to compute the local corrosion degree of the steel pipe pile for the wind turbine and obtain the general corrosion equivalent. The local corrosion effect of the offshore steel pipe pile for the wind turbine was converted into homogeneous corrosion thickness loss of certain length, and then the ultimate strength of the offshore steel pipe pile foundation for the wind turbine was analyzed under the conditions of local corrosion. The result indicates that the maximum ultimate strength reductionof the steel pipe pile for the wind turbine induced by the local corrosion in the splash zone is 80.8% of the non-corrosive ultimate strength. The maximum ultimate strength reduction of the steel pipe pile for the wind turbine induced by the local corrosion in the continuous immersion zone is 63% of the non-corrosive ultimate strength. Once the local corrosion rate in the splash zone exceeds 10%, the ultimate strength of the steel pipe pile for the wind turbine will exhibit a negative exponential decrease. The local corrosion in the continuous immersion zone has a huge effect on its ultimate strength. There are no significant signs of the structural strength loss. The areas prone to local corrosion should be prioritized in anti-corrosion design of the steel pipe pile for the wind turbine.
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Suarsana, I. Ketut, I. Made Astika e I. Gede Putu Agus Suryawan. "Efek perlakuan pack carburizing dan media korosif pada baja AISI 1045 terhadap laju korosi". Jurnal Energi Dan Manufaktur 14, n. 2 (11 gennaio 2022): 37. http://dx.doi.org/10.24843/jem.2021.v14.i02.p01.
Testo completoAbstract (sommario):
Corrosion is a destructive symptom that affects the properties of a metal, which means that the physical properties and quality of the metal decrease due to the electrochemical reaction between the metal and its environment so that the strength of the metal decreases. Corrosion control can be used to avoid the negative impact of corrosion, through the pack carburizing treatment method. The material used in this research is AISI 1045 steel. To determine the effect of pack carburizing on the corrosion rate of steel, the research was carried out by varying the suhue of the carburizing pack and corrosive media. In this study, the pack carburizing process with suhue variations used was 750°C, 850°C, 950°C and the corroding media used were air, fresh water and sea water. This was observed in accordance with the application of AISI 1045 material. The corrosive process through corrosive media was carried out for 720 hours. The results showed that pack carburized steel at a temperature of 950°C had a lower corrosion rate than pack carburized steel at 750°C. Also, air corrosive media provides a lower corrosion rate compared to seawater corrosion rate.
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Li, Li, Jun Ling Tian, Yi Liang Peng e Guo Xin Li. "Investigation on the Anti-Corrosion Layer of the Power Transmission Steel Structures". Applied Mechanics and Materials 427-429 (settembre 2013): 400–403. http://dx.doi.org/10.4028/www.scientific.net/amm.427-429.400.
Testo completoAbstract (sommario):
The power transmission steel structures are used in the outdoor and the durability will be decreased due to the various corrosions, so the structures usually coated the anti-corrosion layers such as hot-dip coating, zinc-rich coating or thermal spray zinc coating. The anti-corrosion layers on three power transmission steel structures in Henan province, China were investigated by the corrosion morphology and the residual coating thickness. The results indicated that the corrosion degree of the bolts is higher than that of the steels, and there are local corrosions occurred on the surface of the steels due to the plating leakage or clash.
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Cai, Yikun, Yuanming Xu, Yu Zhao e Xiaobing Ma. "Atmospheric corrosion prediction: a review". Corrosion Reviews 38, n. 4 (27 agosto 2020): 299–321. http://dx.doi.org/10.1515/corrrev-2019-0100.
Testo completoAbstract (sommario):
AbstractThe atmospheric corrosion of metallic materials causes great economic loss every year worldwide. Thus, it is meaningful to predict the corrosion loss in different field environments. Generally, the corrosion prediction method includes three parts of work: the modelling of the corrosive environment, the calibration of the corrosion effects, and the establishment of the corrosion kinetics. This paper gives an overview of the existing methods as well as promising tools and technologies which can be used in corrosion prediction. The basic corrosion kinetic model is the power function model and it is accurate for short-term corrosion process. As for the long-term corrosion process, the general linear models are more appropriate as they consider the protective effect of the corrosion products. Most corrosion effect models correlate the environmental variables, which are characterized by the annual average value in most cases, with corrosion parameters by linear equations which is known as the dose-response function. Apart from these conventional methods, some mathematical and numerical methods are also appropriate for corrosion prediction. The corrosive environment can be described by statistical distributions, time-varying functions and even geographic information system (GIS), while the corrosion effect can be captured via response surface models and statistical learning methods.
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Pletnev, Mikhail. "Carbon nanocomposites in the corrosion inhibition". E3S Web of Conferences 225 (2021): 05002. http://dx.doi.org/10.1051/e3sconf/202122505002.
Testo completoAbstract (sommario):
Metal-carbon nanocomposites have been investigated as additives to enhance the protective effect of corrosion inhibitors. Two inhibitors were used as corrosion inhibitors. Inhibitor VNH-L-113 (1-morpholinomethylcyclohexylamine) belongs to Schiff bases, which are known as corrosion inhibitors in neutral and acidic media. Inhibitor SNPKh-1004 is often used in the practice of corrosion protection in the oil and gas industry. For research, an electrochemical method was applied using corrosion rate meters of the Monicor type. Neutral aqueous solution and water simulating the corrosive environment of oil fields were chosen as corrosive media. The result shows, that the copper-carbon nanocomposite enhances the protective effect of corrosion inhibitors of various chemical nature in various corrosive environments. The studies carried out make it possible to consider the use of metal-carbon nanocomposites as a promising direction for increasing the effectiveness of inhibitors in the oil and gas industry.
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Umoren, S. A., e M. M. Solomon. "Recent Developments on the Use of Polymers as Corrosion Inhibitors - A Review". Open Materials Science Journal 8, n. 1 (11 luglio 2014): 39–54. http://dx.doi.org/10.2174/1874088x01408010039.
Testo completoAbstract (sommario):
The use of corrosion inhibitors is the one the most economical and practical means of controlling metallic corrosion in different corrosive media. Interest on the use of eco-friendly organic compounds as corrosion inhibitors has extended to the use of polymers to inhibit metallic corrosion. The use of polymers as corrosion inhibitors has attracted attention and has gained wide acceptance in recent times. This has been attributed to a number of factors namely: (i) they are low cost and stable to metallic materials in acid media, (ii) they possess multiple adsorption sites, (iii) through their functional groups, they form complexes with metal ions and on the metal surface these complexes occupy a large area, thereby blanketing the surface and protecting the metal from corrosive agents present in the solution. A number of synthetic and natural polymers as metallic corrosion inhibitors have been investigated and reported. As an update to previous review work on the use of polymers as corrosion inhibitors, the present review presents most of the contributions made to the literature on the use of polymers as corrosion inhibitors of diverse metals in different corrosive media in the last four (2010-2013) years.
26
Guo, Qifeng, Jiliang Pan, Min Wang, Meifeng Cai e Xun Xi. "Corrosive Environment Assessment and Corrosion-Induced Rockbolt Failure Analysis in a Costal Underground Mine". International Journal of Corrosion 2019 (4 marzo 2019): 1–9. http://dx.doi.org/10.1155/2019/2105842.
Testo completoAbstract (sommario):
As an effective ground-reinforcing system, rockbolts have been widely used in underground excavations. Corrosion of rockbolts has been one of the most reasons for rockbolts system failure. In this paper, the chemical composition and pH values of the groundwater in Sanshandao Gold mine are first tested. Corrosion of the slotted rockbolts used in roadways of the mine is analysed. The corrosion rate of rockbolts is evaluated based on experimental results from similar corrosive conditions. A time-dependent analytical model on anchoring force degradation caused by corrosion of the rockbolt is developed. Furthermore, the effects of corrosion rate and geometric parameters of the slotted rockbolts on anchoring force degradation are discussed. Suggestions on rockbolts support design in corrosive conditions are given. It has been found that, with the corrosion time increasing, the anchoring force between the rock and the rockbolt gradually decreases. The larger the corrosion rate is, the faster the anchoring force decreases. For long-term service roadways under corrosive conditions, a slotted rockbolt with a smaller radius and thicker wall can enhance the anchoring force.
27
Liu, Congcong, Zongde Liu, Yuan Gao, Xinyu Wang e Chao Zheng. "High-temperature corrosion behavior of TP91, C22 alloy and C22 based on laser coatings in simulated reducing corrosion environment". Materials Research Express 9, n. 1 (1 gennaio 2022): 016519. http://dx.doi.org/10.1088/2053-1591/ac4732.
Testo completoAbstract (sommario):
Abstract To explore corrosion characteristics of TP91, C22 alloy and C22 laser coatings in reducing environment caused by low-nitrogen combustion at 500 °C–600 °C, a synthetic corrosive medium containing 0.2 vol% H2S-0.1 vol% O2–N2 were selected. Results showed that the order of corrosion resistance is: C22 laser coatings>C22 alloy>TP91. 550 °C was the limit corrosion temperature for C22 alloy and C22 laser coatings. The reason for the strong corrosion resistance of C22 alloy and C22 laser coatings is that a dense layer of Cr-rich corrosion products due to the is produced in the inner layer, thus protecting the matrix from direct corrosion by corrosive gas. Finer grains before corrosion tests and the formation of dense Cr2O3 inner layers in much speedier process were the main reasons for the best corrosion resistance of C22 laser coatings.
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Zhu, Xiaohong, Yingxu Huo, Andy YF Leung, Tarek Zayed e Dan Tsang. "Corrosion of pipes for conveying drinking water in Hong Kong: mechanisms and controlling strategies". HKIE Transactions 31, n. 1 (2024): 1–22. http://dx.doi.org/10.33430/v31n1thie-2022-0045.
Testo completoAbstract (sommario):
A drinking water distribution system (DWDS) ensures access to safe water and provides the basis for city life. However, the pipes in DWDSs are threatened by corrosion externally and internally. This paper critically reviews the mechanisms and types of corrosion in pipes for drinking water, followed by an outline of the related controlling strategies. Special focus is accorded to pipes under the soil environment near coastal areas subjected to seawater intrusion. The corrosion that happens internally (erosion-corrosion, microbially influenced corrosion, and other ions) or those that occur externally (corrosive soils, dissimilar metals, stray current, coating damage, and microbial-influenced corrosion) eventually leads to electrolytic corrosion. It is found that soft soil (partially due to seawater intrusion) is a significant threat to corrosion in DWDSs because it is corrosive and may cause external stress problems for existing DWDSs. Some suggestions and controlling strategies are proposed in the current review.
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Smolyago, G. A., A. V. Dronov e N. V. Frolov. "MODELING OF REDUCTION IN THE CROSS-SECTIONAL AREA OF STEEL REINFORCEMENT IN CONCRETE UNDER THE ACTION OF CORROSIVE ENVIRONMENT". Proceedings of the Southwest State University 21, n. 1 (28 febbraio 2017): 43–49. http://dx.doi.org/10.21869/2223-1560-2017-21-1-43-49.
Testo completoAbstract (sommario):
Process of depassivation of steel in concrete under the action of chloride corrosive environment is considered. Method of durable testing of bended reinforced concrete structures during corrosive period is described. Results of experimental research in steel reinforcement corrosion in reinforced concrete beams under the action of corrosive environment are described in the article. The diagram of corrosive potential changes during the testing time is given in the article. Measurements of corrosion potential were carried out by the corrosion analyzing instrument. Analysis of corrosive potential changes during the testing time was carried out. Main properties and features of chloride corrosion process and damages are considered. Corrosive pits on the surface of the reinforcement bars were studied. Measurements of depth and diameter of the corrosive pits were carried out. Stress-strain diagrams of steel after the corrosive period were obtained. Mathematical model of reduction in the cross-sectional area of steel reinforcement in concrete under the action of corrosive chloride environment is suggested. This model allows to consider effect of concrete cover thickness on depth of corrosion. Comparison of experimental results and theoretical calculations reveals high accuracy of corrosion damage definition by given mathematical model. The ways to use the model are suggested. The given model allows to consider corrosive damages of steel rebars by definition of cross-section area losses and may be used in calculations of strength and deformations of RC structures. It’s possible to use the model for prediction of the remaining strength life of RC structures.
30
Faes, Willem, Steven Lecompte, Zaaquib Yunus Ahmed, Johan Van Bael, Robbe Salenbien, Kim Verbeken e Michel De Paepe. "Corrosion and corrosion prevention in heat exchangers". Corrosion Reviews 37, n. 2 (26 marzo 2019): 131–55. http://dx.doi.org/10.1515/corrrev-2018-0054.
Testo completoAbstract (sommario):
AbstractIn many industries and processes, heat exchangers are of vital importance as they are used to transfer heat from one fluid to another. These fluids can be corrosive to heat exchangers, which are usually made of metallic materials. This paper illustrates that corrosion is an important problem in the operation of heat exchangers in many environments, for which no straightforward answer exists. Corrosion failures of heat exchangers are common, and corrosion often involves high maintenance or repair costs. In this review, an overview is given of what is known on corrosion in heat exchangers. The different types of corrosion encountered in heat exchangers and the susceptible places in the devices are discussed first. This is combined with an overview of failure analyses for each type of corrosion. Next, the effect of heat transfer on corrosion and the influence of corrosion on the thermohydraulic performances are discussed. Finally, the prevention and control of corrosion is tackled. Prevention goes from general design considerations and operation guidelines to the use of cathodic and anodic protection.
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Дронов e Andrey Dronov. "THE PROPERTIES OF PITTING CORROSION OF STEEL REINFORCEMENT OF REINFORCED CONCRETE BEAMS". Bulletin of Belgorod State Technological University named after. V. G. Shukhov 2, n. 3 (4 aprile 2017): 32–36. http://dx.doi.org/10.12737/24678.
Testo completoAbstract (sommario):
Two types of steel reinforcement depassivation process: carbonation of concrete and chloride penetration are considered in the article. The comparison between the corrosion due to carbonation of concrete and the chloride-induced corrosion was carried out. It was found out, that chlorides induced corrosion is potentially more dangerous than that resulting from carbonation. Method of durable tests of reinforced concrete structures under the action of the gravitational load and the corrosive chloride environment is described in the article. The results of experimental research on reinforced concrete structures with corrosive damages to steel reinforcement are given in the article. The properties of corrosion cracking in the case of the pitting corrosion were determined. The character of corrosive damage distribution along the reinforcement bars and its effect on the strength of reinforced concrete beams were determined.
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de Sousa Leite, Kelson, Antônio Alves de Carvalho, Paulo Ronaldo Sousa Teixeira e José Milton Elias de Matos. "Cashew Nut Shell Liquid as an Anticorrosive Agent in Ceramic Materials". Sustainability 15, n. 11 (29 maggio 2023): 8743. http://dx.doi.org/10.3390/su15118743.
Testo completoAbstract (sommario):
One of the significant challenges of the ceramics industry is to increase the corrosion resistance of ceramic materials, and the study of this corrosion requires a detailed investigation using several characterization methods, such as the knowledge of technological properties including the absorption, apparent porosity, and mechanical resistance of these ceramic materials. This corrosion resistance can be further improved by using a protective coating on the surface of ceramic materials, such as cashew nut shell liquid (CNSL), which has been used as a green, environmentally friendly corrosion inhibitor. This work investigated the inhibitory action of CNSL on the corrosion of ceramic materials. Clay from the Brazilian Northeast was used in a simulated seawater environment at room temperature for the immersion corrosion test. Sets of prismatic specimens bathed in CNSL were immersed in a corrosive solution and compared with other samples without CNSL immersed in a corrosive environment. At the end of 70 days in corrosive solution, the ceramic specimens without CNSL showed signs of wear on the surface, associated with an average mass loss of 20 mg and an average corrosive rate of 0.017 mm/year. On the other hand, the bodies bathed in CNSL showed no mass loss, reinforcing the potential of CNSL as a protective agent against corrosion.
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Kumar, Saurabh, Reena Singh e N. S. Maurya. "Assessment of Corrosion Potential Based on Water Quality Index in the Distribution Network of Urban Patna, Bihar, India". Nature Environment and Pollution Technology 21, n. 5(Suppl) (29 dicembre 2022): 2117–27. http://dx.doi.org/10.46488/nept.2022.v21i05.008.
Testo completoAbstract (sommario):
Corrosion in the distribution network pipe can lead to pipe failure and water quality problems. This study assesses the corrosion or scaling potential based on the Water Quality Index (WQI) of drinking water in the distribution networks of Patna, Bihar, India. The water samples were collected from 18 points of the distribution network. In situ parameters like temperature, pH, electrical conductivity, and TDS were measured. Other parameters such as Alkalinity, Total hardness, Calcium, Magnesium, Chloride, Residual chlorine, Sulfate, Nitrate, and Dissolved oxygen were examined in the laboratory. Corrosiveness indicators, such as the Langelier saturation index (LSI), Ryznar stability index (RSI), Puckorius scaling index (PSI), Larson-Skold index (Ls), and Aggressive index (AI) are being used for water sample corrosion prediction. Experimental Corrosion rate (CR) is analyzed to show the actual prediction of corrosion. WQI was calculated to observe the effect of water quality on Corrosiveness indices and CR. A general conclusion was reached that LSI concludes 66.67% corrosive, 22.22% scaling, and 11.11% neutral, RSI concludes 88.88% corrosive, 5.56% scaling, and 5.56% neutral, PSI indicates 38.88% corrosive, 5.56% scaling, and 55.56% neutral, Ls indicates 94.44% scaling, and 5.56% corrosive, AI indicates 77.78% corrosive, and only 22.22% scaling. The average Experimental Corrosion rate is found at 1.91 mils per year. In this study, a weak correlation (r = 0.35) between Corrosion rate and WQI has been observed. A weak correlation is also observed between corrosion rate and corrosiveness indices (r < 0.5). It is concluded that the Corrosiveness Indices fail to represent the actual behavior of water.
34
Ivošević, Špiro, Đenđi Vaštag e Nataša Kovač. "The Analyses of the Corrosion Process of a NI-Ti Shape Memory Alloy in Different Environment". Interdisciplinary Journal of Research and Development 9, n. 4. S2 (20 dicembre 2022): 1. http://dx.doi.org/10.56345/ijrdv9n4s201.
Testo completoAbstract (sommario):
In this paper, we investigate the corrosion process of Ni-Ti alloy obtained by the new continius casting method. As the corrosion rate of the material depends on the environment in which the material is located and the corrosion product that slows down the corrosion process over time, in this paper we analyze changes in the base material and the formed corrosion product. This changes were analysed in three different marine environments and at different time intervals of 6 and 12 months. Investigation on the base Ni-Ti alloy, were conducted on base of analyses of the corrosion depth in nm which was measured using the Focus Ion Beam (FIB) method. The linear model was used to calculate the values of corrosion rate during the time of exposure. On the other hand, the corrosion product of the alloy increased over time, resulting in the formation of a corrosive layer on the alloy surface depending on the environment to which it is exposed. The content of the corrosive product was considered using semi-quantitative energy dispersive X-ray (EDX) analysis, and the percentage of oxygen in the corrosive product that appeared on the alloy in all environmental conditions after 6 and 12 months of exposure. As time is raning, corrosion rate is increasing same as percentage of oxygen in each of considered enviroment. Considering results it can be concluded that the formation of the corrosive layer in the sea has a dominant effect on the deceleration of the corrosion process of Ni-Ti alloy, comparing to the all of three considered enviroment.
Received: 11 September 2022 / Accepted: 19 November 2022 / Published: 20 December 2022
35
Lin, Zhen, Guo Zhang Li, Hong Bai Bai e Chun Hong Lu. "Experimental Investigation on Damping Characteristic of Metal Rubber Material at Simulated Marine Environment". Applied Mechanics and Materials 456 (ottobre 2013): 110–14. http://dx.doi.org/10.4028/www.scientific.net/amm.456.110.
Testo completoAbstract (sommario):
To meet the need of damping material at the marine corrosive environment, the clamped-edge disk type of metal rubber specimen is designed and its corrosion-load alternate experiment is performed, the anti-corrosive and damping characteristic of the material at the marine corrosive environment is researched. The experimental results show that the corrosive rate of 304 stainless steel metal rubber specimen at cycle-immersion corrosion-load alternate environment is the highest and its decay rate of dynamic average rigidity is also the highest, and followed by full-immersion, cycle-salt-spray and full-salt-spray environment. The damping characteristic of metal rubber specimen is relatively stable at the corrosion-load alternate experiment; the metal rubber material has anti-corrosion ability at marine environment.
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Hadi, Syamsul, Sza Sya Monica Valeria, Satworo Adiwidodo, Utsman Syah Amrullah, R. N. Akhsanu Takwim e Hilmi Iman Firmansyah. "Corrosion Rate of Black Chromium Coating Result of Electroplating on Copper". INTEK: Jurnal Penelitian 7, n. 2 (3 febbraio 2021): 128. http://dx.doi.org/10.31963/intek.v7i2.2681.
Testo completoAbstract (sommario):
The problem faced is that the white chromium coating has a low selling value or aesthetic value than the black chromium layer which is more in demand, especially by the younger generation who prioritizes aesthetics. The purpose of the corrosion test was to determine the corrosion resistance ability of the black chromium coating resulting from the electroplating process on the relationship between the solution temperature and the immersion time of copper in a corrosive solution. Corrosion test methods include literature studies, field observations, weighing specimens, immersing specimens in corrosive solutions, weighing specimens, calculating corrosion rates, and data analyzing. Corrosion test results show that the higher the temperature of the solution and the longer the immersion time, the smaller the corrosion rate for the lowest conditions at 30oC and a duration of 5 minutes with a corrosion rate of 0.2004 mm/year and the highest conditions at a temperature of 50oC and a duration of 9 minutes at a rate of corrosion of 0.0108 mm/year.
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Flores-Garcia, N. S., C. D. Arrieta-Gonzalez, J. J. Ramos-Hernandez, G. K. Pedraza-Basulto, J. G. Gonzalez-Rodriguez, J. Porcayo-Calderon e L. Martinez-Gomez. "Rare Earth-Based Compounds as Inhibitors of Hot-Corrosion Induced by Vanadium Salts". Materials 12, n. 22 (19 novembre 2019): 3796. http://dx.doi.org/10.3390/ma12223796.
Testo completoAbstract (sommario):
In this study, the performance evaluation of lanthanum compounds as corrosion inhibitors of vanadium salts was performed. The inhibitors tested were lanthanum acetate and La2O3. The performance of the inhibitors was tested using sodium metavanadate (NaVO3) as a corrosive medium at 700, 800, and 900 °C. The corrosion inhibitory effect was evaluated on the corrosion process of 304H stainless steel. The corrosion rate of the steel was determined by the mass loss technique after 100 h of immersion in the corrosive salt with and without the addition of the corrosion inhibitor. The results show that lanthanum compounds act as corrosion inhibitors of vanadium salts. The inhibitory effect increases by increasing the concentration and tends to decrease when increasing the test temperature. Lanthanum compounds act as excellent corrosion inhibitors due to their ability to stabilize vanadium cations. Vanadium is stabilized by forming a new compound, lanthanum vanadate (LaVO4), with a melting point much higher than the compounds formed when Mg or Ni compounds are used as corrosion inhibitors.
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Martin, Holly J., M. F. Horstemeyer e Paul T. Wang. "Effects of Variations in Salt-Spray Conditions on the Corrosion Mechanisms of an AE44 Magnesium Alloy". International Journal of Corrosion 2010 (2010): 1–10. http://dx.doi.org/10.1155/2010/602342.
Testo completoAbstract (sommario):
The understanding of how corrosion affects magnesium alloys is of utmost importance as the automotive and aerospace industries have become interested in the use of these lightweight alloys. However, the standardized salt-spray test does not produce adequate corrosion results when compared with field data, due to the lack of multiple exposure environments. This research explored four test combinations through three sets of cycles to determine how the corrosion mechanisms of pitting, intergranular corrosion, and general corrosion were affected by the environment. Of the four test combinations, Humidity-Drying was the least corrosive, while the most corrosive test condition was Salt Spray-Humidity-Drying. The differences in corrosivity of the test conditions are due to the various reactions needed to cause corrosion, including the presence of chloride ions to cause pit nucleation, the presence of humidity to cause galvanic corrosion, and the drying phase which trapped chloride ions beneath the corrosion by-products.
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Rasheed, Usman, Hyundong Lee, Myeongsik Kong e Pilljae Kwak. "A study on the corrosion index of Tap Water(TW) and Reclaimed Water(RW) using KWI(Korea Water Index) and KRWI(Korea Reclaimed Index Water) method". International Journal of Engineering & Technology 7, n. 3.33 (29 agosto 2018): 209. http://dx.doi.org/10.14419/ijet.v7i3.33.21014.
Testo completoAbstract (sommario):
This study aim to find the corrosion index of Tap water and Reclaimed water using KWI (Korea Water Index) and KRWI (Korea Reclaimed Water Index) method. The impact of corrosion inhibiting factors (pH ,hardness, alkalinity) and corrosion accelerating facor (TDS, chlorine ion, sulphate ion) has studied. The corrosion assessment method based on the corrosion index is used in predicting corrosion and offering information on the control of corrosive water quality.
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Hussain, Mahmoud. "Synthesis, Characterization and evaluation of new". JOURNAL OF ADVANCES IN CHEMISTRY 12, n. 2 (16 dicembre 2016): 3956–63. http://dx.doi.org/10.24297/jac.v12i2.2153.
Testo completoAbstract (sommario):
ABSTRACT A new polymer surfactant derived from cis-1,4-cyclohexane bis(methylamine) and ethylenediamintetraacetic acid [2,2'-(1,12-bis(4-(aminomethyl)cyclohexyl)-3,10-dioxo-2,5,8,11-tetraazadodecane-5,8-diyl) diacetic acid ] was synthesized and characterized by FTIR and 1HNMR. A series of electrochemical measurements, including corrosion potential and corrosion current has been made on the surfactant for carbon steel samples in corrosive environment. Results showed that the surfactant can offer some degrees of protection in the corrosive environments. The corrosion study of this polymer outline that it have a good resistant to the corrosion of carbon steel in 0.1 M solution of HCl, which can be indicate to uses as anti-corrosion materials
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Kubzová, Monika, Vit Křivý, Viktor Urban e Katerina Kreislova. "Corrosive Environment Factors and their Influence on the Development of Weathering Steel Corrosion Products". Key Engineering Materials 832 (febbraio 2020): 137–46. http://dx.doi.org/10.4028/www.scientific.net/kem.832.137.
Testo completoAbstract (sommario):
This article deals with the topic of atmospheric corrosion. Atmospheric corrosion causes damage to nearly 80% of all existing steel structures. The main parameters of atmospheric corrosion are the time of wetness (TOW), air temperature and aggressive corrosive agents such as chlorides, sulfur dioxide and others. Currently, low alloy steels with improved atmospheric corrosion resistance called weathering steels are used for the steel structures located in outdoor environment. A protective layer of corrosion products is created on the steel surface and this layer can reduce continuation of corrosion of steel. The time of wetness together with the effect of aggressive corrosive agents are various for surfaces oriented vertically or horizontally. Experimental tests of atmospheric weathering steel were carried out to monitor the impact of location and position of surface on the different constructions. These tests allow monitoring the development of corrosion products in real exposures. The article presents a part of the research, which includes monitoring the development of the thickness of corrosion products with regard to the position on the structure. Research is developed to refine of prediction models with the aim of improving determination of corrosion losses during the service life of the structure. Second part of these experiments is dedicated to measuring the deposition rate of chlorides. Chlorides have a corrosive impact on the steel surface. Under normal conditions the chlorides does not create suitable environment for the development of a protective layer of corrosion products.
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Yahya, Febriyandhi, Ade Trisnawati e Mohammad Arfi Setiawan. "The effect of sambiloto leaf (Andrographis paniculata Nees) extract inhibitor concentration on the corrosion rate of iron in the corrosive HCl medium and well water". Jurnal Pijar Mipa 18, n. 2 (31 marzo 2023): 274–78. http://dx.doi.org/10.29303/jpm.v18i2.4780.
Testo completoAbstract (sommario):
Corrosion is a chemical reaction between metal and chemical substances in free air influenced by typographical conditions, climate, and humidity levels around the metal object. If left unchecked, it can cause damage to the metal infrastructure, material losses, and harm in terms of safety and security. Therefore, a way to inhibit corrosion is needed by creating an environmentally friendly inhibitor from natural materials. One of them is by utilizing Sambiloti leaf as a natural inhibitor. Sambiloto leaves contain tannins which can inhibit corrosion well. This study aimed to determine the efficiency of Sambiloto leaves ethanol extract in inhibiting the corrosion rate of metals in the corrosive medium of well water. HCl was soaked for seven days to determine the correlation between the corrosion rate and extract concentration in different corrosive media. Sambiloto leaves were extracted using the soxhletation method using 96% ethanol solution, then distilled to obtain a pure extract. Sambiloto leaf extract was then varied in concentration, namely 1%, 5%, 10%, and 15%. The corrosive medium is well water and HCl, and the metal material used is nails. The results showed that adding Sambiloto extract with a concentration of 15% in both corrosive mediums had the highest inhibitor efficiency values, namely 97.32% in the corrosive HCl medium and 69.3% in the corrosive well water medium. The results of the regression analysis showed that the addition of Sambiloto extract had a significant effect on the corrosion rate in well water media. In contrast, in the HCl medium, the addition of Sambiloto extract did not significantly affect the corrosion rate.
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Fu, Lei, Hui Li, Li Lin, Qingyuan Wang, Qi Fan, Xinjie Huang, XiuLan Li, Sheng Lai e Lifei Chen. "Corrosion mechanism and fatigue behavior of 2A70-T6 aluminum alloy under alternating corrosion and fatigue". Anti-Corrosion Methods and Materials 68, n. 5 (2 settembre 2021): 422–37. http://dx.doi.org/10.1108/acmm-02-2020-2265.
Testo completoAbstract (sommario):
Purpose Most supersonic aircraft were manufactured using 2A70 aluminum alloy. The purpose of this paper is to study the corrosion mechanism and fatigue behavior of an aircraft in a semi-industrial atmospheric corrosive environment, alternating effects of corrosion and fatigue were used to simulate the aircraft’s ground parking corrosion and air flight fatigue. Design/methodology/approach For this purpose, the aluminum alloy samples were subjected to pre-corrosion and alternating corrosion-fatigue experiments. The failure mechanisms of corrosion and corrosion fatigue were analyzed using microscopic characterization methods of electrochemical testing, X-ray diffraction and scanning electron microscopy. Miner’s linear cumulative damage rule was used to predict the fatigue life of aluminum alloy and to obtain its safe fatigue life. Findings The results showed that the corrosion damage caused by the corrosive environment was gradually connected by pitting pits to form denudation pits along grain boundaries. The deep excavation of chloride ions and the presence of intergranular copper-rich phases result in severe intergranular corrosion morphology. During cyclic loading, alternating hardening and softening occurred. The stress concentration caused by surface pitting pits and denudation pits initiated fatigue cracks at intergranular corrosion products. At the same time, the initiation of multiple fatigue crack sources was caused by the corrosion environment and the morphology of the transient fracture zone was also changed, but the crack propagation rate was not basically affected. The polarization curve and impedance analysis results showed that the corrosion rate increases first, decreases and then increases. Fatigue failure behavior was directly related to micro characteristics such as corrosion pits and microcracks. Originality/value In this research, alternating effects of corrosion and fatigue were used to simulate the aircraft’s ground parking corrosion and air flight fatigue. To study the corrosion mechanism and fatigue behavior of an aircraft in a semi-industrial atmospheric corrosive environment, the Miner’s linear cumulative damage rule was used to predict the fatigue life of aluminum alloy and to obtain its safe fatigue life.
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Sun, Jie, Wenxiang Zhao, Pei Yan, Kaijie Chen, Li Jiao, Tianyang Qiu e Xibin Wang. "Effect of Corrosive Medium and Surface Defect-Energy on Corrosion Behavior of Rolled ZK61M Alloy". Materials 15, n. 12 (9 giugno 2022): 4091. http://dx.doi.org/10.3390/ma15124091.
Testo completoAbstract (sommario):
Magnesium alloys have been widely used as lightweight engineering structural materials, but their service performances are severely restricted by corrosion failure. In this paper, the influence of corrosive medium and surface defect energy on the corrosion behavior of rolled ZK61M alloy was investigated. The corrosion tests were conducted in different concentrations of sodium chloride solution for different durations, and the polarization curves and electrochemical impedance spectroscopy were reported. The surface morphology of rolled ZK61M alloy before and after corrosion tests were analyzed. The results showed that the corrosion tendency became stronger with the increase of the concentration of corrosive medium and the number of surface defects of ZK61M alloy. Moreover, the initial corrosion pattern was the pitting caused by micro galvanic corrosion at the surface defect, which gradually developed into uniform corrosion. Furthermore, the main damage occurred at the grain boundary, resulting in the destruction of grain bonding force and the removal of material along the rheological layer. The oxidation corrosion mechanism was mainly the anodic dissolution mechanism.
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Ali, Murad, Anwar Ul-Hamid, Tayyab Khan, Abdulhakim Bake, Haider Butt, Olufemi Eyitope Bamidele e Aamer Saeed. "Corrosion-related failures in heat exchangers". Corrosion Reviews 39, n. 6 (25 ottobre 2021): 519–46. http://dx.doi.org/10.1515/corrrev-2020-0073.
Testo completoAbstract (sommario):
Abstract Corrosion is the primary cause of failure of heat exchangers in industry, especially in the oil and petrochemical sector. The modes of failure related to corrosion include erosion corrosion, pitting corrosion, crevice corrosion, grain boundary corrosion, dealloying, galvanic corrosion, stress corrosion cracking, waterside corrosion, uniform corrosion, and microbially induced corrosion. Primary causes of corrosion-related failures were found to be fabrication and welding defects, presence of residual stresses, inappropriate materials selection and design, improper water chemistry/flow and poor choice of filters, presence of corrosive species such Cl−, Sx−, O2, NH4 + in water, nonadherence to recommended operating conditions, and noncompliance with standard practices during the shutdown. This article is a review covering only corrosion-related failures in heat exchangers.
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Li, Ning, Weifang Zhang, Hai Xu, Yikun Cai e Xiaojun Yan. "Corrosion Behavior and Mechanical Properties of 30CrMnSiA High-Strength Steel under an Indoor Accelerated Harsh Marine Atmospheric Environment". Materials 15, n. 2 (14 gennaio 2022): 629. http://dx.doi.org/10.3390/ma15020629.
Testo completoAbstract (sommario):
In this work, the corrosion behavior and mechanical properties of 30CrMnSiA high-strength steel under a harsh marine atmosphere environment were systematically studied using accelerated test technology, along with corrosion kinetic analysis, microstructure and phase composition analysis, electrochemical measurements, and mechanical property tests. The influence of corrosion time on corrosion kinetics was characterized by the weight loss method. The corrosion layer and its product evolution were analyzed by SEM, EDS, XRD, and XPS. The corrosion behavior of steel was studied by a potentiodynamic polarization curve and EIS. Finally, the influence of corrosion on mechanical properties was studied by tensile and fatigue tests. The results show that 30CrMnSiA high strength steel has good corrosion resistance in a harsh marine atmosphere environment. Its corrosion behavior is cyclical: the outer rust layer exfoliated, the inner rust layer became the outer rust layer, and the matrix became inner rust due to the attack by the corrosive medium. The rust layer had a great protective effect on the matrix. The mechanical properties of 30CrMnSiA high-strength steel were reduced under the corrosive environment, and corrosion had a significant effect on its fatigue resistance.
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Li, Ming, Huajie Wu e Yanhui Sun. "Corrosion Performance of Welded Joints for E40 Marine Steel". Metals 13, n. 9 (28 agosto 2023): 1528. http://dx.doi.org/10.3390/met13091528.
Testo completoAbstract (sommario):
Marine steel requires excellent toughness and corrosion resistance in a low-temperature seawater environment. In this study, corrosion tests on E40 steel were performed, including electrochemical testing of the weld metal and heat-affected zone, dynamic corrosion testing in a simulated seawater environment, and the analysis and comparison of results obtained using different methods. The corrosion resistance of E40 was determined by measuring the saturation current density of the anodic dissolution of the steel in a corrosive medium by an electrochemical method. Under laboratory conditions, the corrosion resistance was investigated under simulated seawater. The results showed that regions with uneven microhardness corresponded to the inhomogeneity of the corrosion potential, with measured fluctuations of up to 40 mV. Nanoscale corrosive–aggressive non-metallic inclusions served as a substrate for the deposition of titanium and niobium carbonitrides, thereby weakening the corrosion resistance. The corrosion rate of the base metal was 1.16–1.64 mm/year, which was slightly higher than that of the heat-affected zone. The influence of deposition on the corrosion performance of welded joints under different deoxygenation processes was studied, and the deposition composition was controlled by a deoxygenation process to improve the corrosion resistance of the steel plate.
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Cheng, Yuanpeng, Yu Bai, Shanfa Tang, Dukui Zheng, Zili Li e JianGuo Liu. "Corrosion behavior of X65 steel in CO2-saturated oil/water environment of gathering and transportation pipeline". Anti-Corrosion Methods and Materials 66, n. 5 (2 settembre 2019): 671–82. http://dx.doi.org/10.1108/acmm-02-2019-2081.
Testo completoAbstract (sommario):
Purpose The purpose of this paper is to investigate the corrosion behavior of X65 steel in the CO2-saturated oil/water environment using mass loss method, potentiodynamic polarization technique and characterization of the corroded surface techniques. Design/methodology/approach The weight loss analysis, electrochemical study and surface investigation were carried out on X65 steel that had been immersed in the CO2/oil/water corrosive medium to understand the corrosion behavior of gathering and transportation pipeline steel. The weight loss tests were carried out in a 3 L autoclave, and effects of water cut and temperature on the CO2 corrosion rate of X65 steel were studied. Electrochemical studies were carried out in a three-electrode electrochemical cell with the test temperature was 60°C, and the CO2 partial pressure was 1 atm by recording open circuit potential/time and potentiodynamic polarization characteristics. The surface and cross-sectional morphologies of corrosion product scales were characterized using scanning electron microscopy. The phases of corrosion product scales were investigated using x-ray diffraction. Findings The results showed that due to the wetting and adsorption of crude oil, the corrosion morphology of X65 steel changed under different water cuts. When the water cut of crude oil was 40-50 per cent, uniform corrosion occurred on the steel surface, accompanied by local pitting. While the water cut was 70-80 per cent, the resulting corrosion product scales were thick, loose and partial shedding caused platform corrosion. When the water cut was 90 per cent, the damaged area of platform corrosion was enlarged. Crude oil can hinder the corrosion scales from being dissolved by the corrosive medium, and change dimension and accumulation pattern of the crystal grain, thickness and structure of the corrosion scales. Under the corrosion inhibition effect of crude oil, the temperature sensitive point of X65 steel corrosion process moved to low temperature, appeared at about 50°C, lower corrosion rate interval was broadened and the corrosion resistance of X65 steel was enhanced. Originality/value The results can be helpful in selecting the applicable corrosion inhibitors and targeted anti-corrosion measures for CO2-saturated oil/water corrosive environment.
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Cheng, Yuanpeng, Zili Li, Yalei Zhao, Yazhou Xu, Qianqian Liu e Yu Bai. "Effect of main controlling factor on the corrosion behaviour of API X65 pipeline steel in the CO2/oil/water environment". Anti-Corrosion Methods and Materials 64, n. 4 (5 giugno 2017): 371–79. http://dx.doi.org/10.1108/acmm-04-2016-1665.
Testo completoAbstract (sommario):
Purpose The purpose of this paper was to investigate the corrosion behaviour of API X65 pipeline steel in the simulated CO2/oil/water emulsion using weight loss technique, potentiodynamic polarization technique and characterization of the corroded surface techniques. Design/methodology/approach The weight loss analysis, electrochemical study and surface investigation were carried out on API X65 pipeline steel that had been immersed in the CO2/oil/water corrosive medium to understand the corrosion behaviour of gathering pipeline steel. The weight loss tests were carried out in a 3L autoclave, and effects of temperature, CO2 partial pressure, water cut and flow velocity on the CO2 corrosion rate of API X65 pipeline steel were studied. Electrochemical studies were carried out in a three-electrode electrochemical cell with the test temperature was 60°C, and the CO2 partial pressure was 1 atm by recording open circuit potential/time and potentiodynamic polarization characteristics. The surface and cross-sectional morphologies of corrosion product scales were characterized using scanning electron microscopy. The phases of corrosion product scales were investigated using X-ray diffraction. Findings The results showed that water cut was the main controlling factor of API X65 steel corrosion under the conditions of CO2/oil/water multiphase flow, and it had significant impact on corrosion morphology. In the case of higher water cut or pure water phase, general corrosion occurred on the steel surface. While water cut was below 70 per cent, corrosion morphology transformed into localized corrosion, crude oil decreased corrosion rate significantly and played a role of inhibitor. Crude oil hindered the corrosion scales from being dissolved by corrosive medium and changed dimension and accumulation pattern of the crystal grain, thickness and structure of the corrosion scales; thus, it influenced the corrosion rate. The primary corrosion product of API X65 steel was ferrous carbonate, which could act as a protective film at low water cut so that the corrosion rate can be reduced. Originality/value The results can be helpful in selecting the suitable corrosion inhibitors and targeted anti-corrosion measures for CO2/oil/water corrosive environment.
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Brezinová, J., J. Koncz, D. Draganovská e A. Guzanová. "The evaluation of corrosion properties of coated materials by utilization of EIS". Koroze a ochrana materialu 60, n. 2 (1 giugno 2016): 35–40. http://dx.doi.org/10.1515/kom-2016-0006.
Testo completoAbstract (sommario):
Abstract The paper presents results of research aimed at determining the corrosive properties of steel with cathode metal coating in selected corrosive environments. The corrosion properties of the tin coated steel were evaluated using electrochemical impedance spectroscopy and potentiodynamic tests. For realised measurements, distilled water, 0.5 mol dm−3 NaCl solution, 0.1 mol dm−3 NaCl solution and SARS, which simulates acid rain were used as corrosive solutions. Both corrosion methods are suitable for diagnosing corrosion properties of steel with metal coatings.