Articoli di riviste: "Corrosion efficiency"

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Strachotová, K. C., M. Kouřil, K. Kuchťáková e Š. Msallamová. "Inhibition efficiency of sodium salts of carboxylic acids on corrosion of lead in archive environment". Koroze a ochrana materialu 63, n. 1 (1 marzo 2019): 37–47. http://dx.doi.org/10.2478/kom-2019-0005.

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Abstract Lead in archive environment suffers from severe corrosion attack caused by the organic acids’ vapours usually presented in such an environment. One of possible ways of corrosion protection of lead is its surface treatment by solutions of sodium salts of monocarboxylic acids (general formula CH3(CH2)n-2COONa, noted NaCn, n = 10, 11, 12). The principle of this corrosion protection is a creation of conversion coating on the lead’s surface, which decreases corrosion rate of lead in the atmospheric environment polluted by organic acids’ vapour. Our research aims at the selection of a suitable protection system that would be applicable to conservation of historical lead in archives and museums. This paper evaluates the corrosion behaviour of treated lead based on the values of polarisation resistance and shape of potentiodynamic curves in simulated corrosive environment (0.01 mol l−1 solution of acetic acid). The lead samples with different state of surface (pure, corroded and electrochemically cleaned) were treated with sodium salts of monocarboxylic acids NaCn (n = 10, 11, 12) having concentration of 0.01 and 0.05 mol l−1. In simulated corrosive atmosphere (above 0.001 mol l−1 acetic acid solution vapours), corrosion rate was measured by means of electrical resistance technique. The inhibition efficiency of monocarboxylic acids is dependent on their carbon chain length and their concentration. The greatest inhibiting efficiency in corrosive atmospheres and for all lead samples was observed for the sodium salt of dodecanoic acid having concentration of 0.05 mol l−1. Artificially created corrosion products and salt coatings were analysed by X-ray diffraction analysis and their surface morphology was observed by scanning electron microscopy. A protective salt coatings are mainly composed of metallic soaps in dimer form.

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Hou, Zhen Bo, Tian Hao Li, Xian Wei Lv e Bing Ge Fu. "Influence of Imidazoline Inhibitor on CO₂ Corrosion of N80 Steel in Annulus Zone of Pump Recovery Well". Advanced Materials Research 1061-1062 (dicembre 2014): 49–54. http://dx.doi.org/10.4028/www.scientific.net/amr.1061-1062.49.

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The impact of CO2 partial pressure ,fluid producing rate and corrosive medium on the CO2 corrosion regularity of N80 steel and the inhibition efficiency of imidazoline inhibitor are investigated respectively through simulation of the actual working environment in the mined-out space of mechanical oil production wells by using high temperature and pressure reactor. According to the results, the corrosion rate of metals increases with CO2 partial pressure but the inhibition efficiency of the inhibitor is hardly affected when CO2 partial pressure in the scope of 1~3MPa. The increase of the fluid producing rate will accelerate the corrosion of metals and the inhibition efficiency will decline. With corrosion inhibitor applied, metals corrode slower in the liquid phase than in the gas in the initial stage, but latterly the corrosion rate is gradually higher than that in the gas phase.

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Augustin, M., e M. Ščerbejová. "Anticorrosive efficiency of preservants for farming machinery". Research in Agricultural Engineering 49, No. 1 (8 febbraio 2012): 22–26. http://dx.doi.org/10.17221/4947-rae.

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Selected anticorrosion preserving agents were subjected to a comparison on the basis of tests made under operating conditions. Resistance of materials to corrosion markedly varies with operating conditions and impact of outer environment with the most important factors influencing the corrosion rate being SO<sub>2</sub> content, temperature and humidity. Relative protective efficiency of preserving agents was assessed on the basis of weight losses of protected and unprotected samples. It was found out that the material’s resistance to corrosion is significantly depending on warehousing conditions (SO<sub>2</sub>, temperature, humidity, etc.) and on the quality of the applied preservant. Depending on various environments, the values of relative protective efficiency of water-soluble preservant and preserving agent based on vegetable oils were ranging from 38–87% and 47–75%, respectively.

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Ushakov, I. A., V. S. Nikonova, I. V. Polynskii, L. G. Knyazeva, M. M. Polynskaya e E. A. Antsiferov. "Study on efficiency of corrosion inhibitors based on derivatives of isothiuronic salts". Proceedings of Universities. Applied Chemistry and Biotechnology 11, n. 2 (4 luglio 2021): 326–32. http://dx.doi.org/10.21285/2227-2925-2021-11-2-326-332.

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Metals play a pivotal role in industry; their use constantly grows. It is virtually impossible to find an industrial field without the use of metals and their alloys. However, owing to the quality degradation of metal during the operational process, corrosion appears not only on its surface but also under a coating, which leads to its destruction. To avoid this, corrosion inhibitors are necessary. Organic compounds have been widely used as corrosion inhibitors. Many organic corrosion inhibitors have been developed nowadays. In the literature, organic compounds comprising N, O, S and P heteroatoms are described, which reduce corrosion rate. The organic compounds are adsorbed on the metal surface, forming a thin layer. Adsorption occurs either through electrostatic interaction or, in some cases, the formation of covalent bonds. The work aimed to study isothiuronic salts as corrosion inhibitors to evaluate their protective properties using the polarisation curves method. Objects of research were isothiuronic compounds containing two active centres separated by saturated and unsaturated carbon bonds (structures 1-3). In structures 4-7, one isothiuronic fragment has different propylene substituting groups. It has been previously shown that these compounds can act as effective brightening agents when applying nickel coatings. A model solution with a density of 1.12 g/cm3 was prepared to study the corrosion inhibitors. The corrosion inhibitor concentration was 400 mg/L. Studies have shown that the compounds with two isothiuronic moieties do not always exhibit improved properties for inhibiting metal degradation in a corrosive environment. In particular, they showed worsening of the inhibiting properties for samples made of steel 20 and identical properties for that made of steel 3.

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Yang, Na, Qin Liao, Qing Li, Peng Zhang e Longqin Li. "Simple and easy-operated method for filtering eco-friendly corrosion inhibitors". Anti-Corrosion Methods and Materials 63, n. 2 (7 marzo 2016): 73–81. http://dx.doi.org/10.1108/acmm-07-2014-1406.

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Purpose – The purpose of this paper was to find a simple and easy-operated method for filtering eco-friendly corrosion inhibitors. Design/methodology/approach – The molecular structures and atomic electronegativities of the four kinds of natural reagents, iota-Carrageenan, sodium alginate, sodium dodecanesulphonate (SDS) and sodium dodecylbenzene sulfonate were calculated by Gaussian and Natural Bond Orbital, and the corrosion inhibition rates were forecasted by the calculated results. Then, the realistic corrosion inhibition efficiency were confirmed by electrochemical impedance spectroscopy and potentiodynamic polarization tests in 3.5 Wt.% sodium chloride corrosive solutions. At the same time, the function of pefloxacin mesylate (PM) was explored in this paper polarization tests in 3.5 Wt.% sodium chloride corrosive solutions. Findings – Results showed that the order calculated by the chemical software was correct, and the corrosion inhibition of SDS was the best. Optimum addition of PM not only can reduce microbial corrosion but also can improve the corrosion inhibition by spatial cooperation. Practical implications – This method can be used to filter eco-friendly corrosion inhibitors quickly. PM can be also used to improve the corrosion inhibition rate of corrosion inhibitors. Originality/value – The present method to filter corrosion inhibitors was time-consuming, which needed lots of experiments to verify the corrosion inhibitive efficiency. The calculated method was simpler than others, which need complicated calculation process.

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Taranza, Luboš, e Rostislav Drochytka. "Verification of the Efficiency of Anti-Corrosion Systems for Reinforced Concrete Constructions in a Laboratory Environment". Applied Mechanics and Materials 357-360 (agosto 2013): 876–79. http://dx.doi.org/10.4028/www.scientific.net/amm.357-360.876.

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Corrosion of steel constructions due to the affection of aggressive agents is one of the principal problems affecting reinforced concrete constructions. In critical cases, this phenomenon may cause static destabilisation of the construction and as a result, it is necessary to protect constructions using primary and secondary protection which significantly decreases this risk. This paper addresses the options for evaluating various types of protective anti-corrosion systems which use progressive corrosion inhibitor technology in a laboratory environment. Corrosion inhibitors efficiently slow down the course of corrosive processes on steel reinforcement and prolong the service life of building constructions. The rate of efficiency can be verified with high information capability in the laboratory by a series of testing methods.

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Vigdorovich, V. I., L. E. Tsygankova, E. Yu Shel, N. V. Shel, L. G. Knyazeva, A. V. Dorokhov e A. A. Uryadnikov. "Modeling of corrosive atmospheres for evaluation of the efficiency of volatile inhibitors". Industrial laboratory. Diagnostics of materials 84, n. 7 (8 agosto 2018): 42–46. http://dx.doi.org/10.26896/1028-6861-2018-84-7-42-46.

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A method of modeling aggressive atmospheres used for different tests in corrosive environments close as possible to actual full-scale conditions is proposed. The method provides simulation of air atmospheres containing gaseous corrosion stimulants (CS) as microcomponents of air. The content of SCs in such atmospheres (both separately and together) can be set and maintained at an unchanged level within a wide range for as long as desired. The method is based on Henry’s equation characterizing concentration of the gas dissolved in a liquid phase as a function of the gas partial pressure in the equilibrium gas medium with allowance for the solubility of the corrosion stimulants in water in conditions under consideration. The procedure is easy to use and does not require long special training. Samples of corrosion stimulants NH3, CO2, and H2S are considered. Experimental results characterizing the corrosion rate of St3 carbon steel and copper with one or several CS simultaneously present in air atmosphere, as well as data on the efficiency of volatile inhibitors of «IFHAN» series under similar conditions are presented.

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Gaidar, Sergey M., Ruslan K. Nizamov, Mikhail I. Golubev e Ivan G. Golubev. "Protective Efficiency of Water-Soluble Corrosion Inhibitors". Mordovia University Bulletin 28, n. 3 (20 settembre 2018): 429–44. http://dx.doi.org/10.15507/0236-2910.028.201803.429-444.

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Introduction. As a result of damage to agricultural and forestry machines from corrosion, the costs of maintaining their performance are increasing. The use of water-soluble inhibitors can slow or halt the destructive process. However, many of the inhibitors have disadvantages, for example, flammability or toxicity. The purpose of this work is to study the protective effectiveness of aqueous solutions of boric acid ester and triethanolamine and to develop recommendations for their use for anticorrosive protection of agricultural and forestry machinery in long-term storage. Materials and Methods. Protective compositions were prepared by dissolving boric acid ester and triethanolamine in distilled and industrial water at room temperature. Aqueous solutions with a concentration of water-soluble inhibitors of 5–50 g/l (0.5–5 mass %) were used for research. The linear polarization resistance method was used to assess their protective efficiency. Solartron (UK) measuring complex was used for electrochemical studies. Accelerated corrosion tests were carried out on steel plates according to GOST 9.054-75 in the g-4 humidistat. The aftereffect of water-soluble corrosion inhibitors was evaluated by the residual film protective efficiency. Results. The influence of the concentration of the ester of boric acid and triethanolamine in aqueous solutions for their protective properties is studied. It was found that boric acid and triethanolamine slow the anode reaction. The analysis of the research results has showed that the corrosion rate of the steel electrode decreases with increasing the concentration of water-soluble inhibitor in process water. This decrease is the most noticeable when the concentration in the range of 10–50 g/l with an increase in the concentration in the solution of boric acid and triethanolamine to 50 g/l, their protective efficiency varies by 6–14 %. The optimal concentration of the inhibitor in the composition is obtained, which is 10 g/l during corrosion tests of steel plates, the protective efficiency of the solution with a concentration of 10 g/l of the water-soluble inhibitor was more than 70 %. In case of precipitation on the samples, the protective efficiency of the solutions decreased to 20–25 %. When tested in a closed unheated room on steel samples during the year there were no traces of corrosion. Conclusions. The study demonstrates that boric acid and triethanolamine is a watersoluble inhibitor of anodic corrosion. When the concentration of water-soluble inhibitor in process water increases, the corrosion rate of the steel electrode decreases. Optimum concentration of ester of boric acid and triethanolamine in the protective solution should be 10 g/l. For corrosion tests of steel plates, the shielding effectiveness of a solution of water- soluble inhibitor was more than 70 %. In the conditions of direct exposure to atmospheric precipitation on the samples of the protective efficiency of the solutions decreased to 20–25 %. When tested in a closed unheated room on steel samples there were no traces of corrosion during the year. Thus, the ester of boric acid and triethanolamine is effective to protect against atmospheric corrosion in a closed room. it Is recommended to apply it for protecting cars against corrosion at short-term storage on open platforms. The application field of water-soluble inhibitor when agricultural and forestry machines are retained for long-term storage is defined; combine stages of cleaning cars from pollution and preserving their surfaces for protection against corrosion are offered. The article will be useful to specialists in the field of protection of agricultural machinery from corrosion.

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Agboola, Oluranti, Toluwani Adedoyin, Ojo Sunday Isaac Fayomi, Ayoola Ayodeji, Samuel E. Sanni, Augustine Omoniyin Ayeni, Patricia Popoola et al. "DNA Inhibition of Hydrogen Ion-Induced Corrosion of Mild Steel Used for Pipelines in Oil and Gas Industries". Asian Journal of Chemistry 33, n. 4 (20 marzo 2021): 767–74. http://dx.doi.org/10.14233/ajchem.2021.22686.

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Corrosion of mild steel via chemical reaction in a corrosive environment is a problematic occurrence that is very common in oil and gas industries. Corrosion constitutes a huge part of the total costs in the production of oil and gas. Corrosion inhibitors have found interest in the scientific domain because they are mainly understood by their chemical complexes and formulations. Their utilization in small amount on metal surface used in oil and gas industries can help shield the metal from corrosion devoid of any significant alteration in the concentration of the corrosive media in the environment. An effort was made to study the possibility of using calf thymus gland DNA (CTGDNA) inhibitor in chlorine induced mild steel for possible usage in piping in oil and gas industry. The SEM micrograph shows that the adsorption of the CTGDNA biomacromolecules coat on the mild steel surfaces functions as a protection against HCl corrosive solution. Electrochemical study and weight loss analysis showed that the inhibitor efficiency (70.48 and 72%, respectively) of the tested DNA (CTGDNA) in HCl acidic corrosion environment for the mild steel was high at 1.5 M of HCl. The inhibitor efficiency decreased with increasing HCl concentrations. The open circuit potential (OPC) revealed that the mild steels got corroded until the end of the immersion. The intensities of XRD peak substantiate the existence of corrosion products of FeCl2.

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Mas’ud, Zainal Alim, Noviyan Darmawan, Januari Dawolo e Yusuf Bramastya Apriliyanto. "Fatty Amidine as Copper Corrosion Inhibitor". Journal of Chemistry 2020 (4 novembre 2020): 1–8. http://dx.doi.org/10.1155/2020/1092643.

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The development of green and sustainable corrosion inhibitors for copper in a corrosive marine environment is highly desired. Herein, we studied the fatty acid-based amidine as the new type of renewable corrosion inhibitor. Stearamidine salt was used as a model inhibitor, and it was synthesized through stearonitrile intermediate with an excellent isolated yield of 88%. We used electrochemical (potentiodynamic polarization) and morphological (scanning electron microscopy) measurements to assess the corrosion inhibition efficiency of stearamidine in 3.0 wt.% NaCl at 300 K. We show that, in such a condition, the optimum inhibition efficiency of 96% was achieved using only 0.2 mM stearamidine. The results suggested the fatty amidine is a promising corrosion inhibitor for copper that is suitable in the saltwater ecosystem. The thermodynamic parameters of the interaction between the stearamidine and the copper surface were determined, and the result suggests that the adsorption process occurred accordingly with the Langmuir adsorption isotherm and involved both physisorption and chemisorption.

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Triana, Yunita, Sari Shaimah Rinda, Awali Jatmoko e Sulistijono Sulistijono. "Studi Penambahan Inhibitor Organik Ekstrak Daun Bawang Tiwai (Eleutherine americana Merr.) pada Baja API 5L dalam Lingkungan 3,5% NaCl". SPECTA Journal of Technology 2, n. 3 (13 dicembre 2018): 1. http://dx.doi.org/10.35718/specta.v2i3.11.

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One that can be used as an organic inhibitor is bawang tiwai leaves extract. This study used 3.5% NaCl as corrosive media with inhibitor concentration of bawang tiwai leaves extract from 0 ppm to 500 ppm and immersion time from 10 days up to 30 days. The efficiency of inhibition was measured using a weight loss corrosion test, while the corrosion rate was obtained from polarization measurements. The FTIR test results show that the extract contains flavonoid compounds that act as antioxidants and inhibit corrosion. Inhibitory efficiency achieved up to 95.4545% for the addition of 300 ppm inhibitor and 20 days of immersion time. This inhibitory behavior is also supported by polarization measurements where the lowest corrosion rate of 0.00128 mm/year is obtained at the same concentration and immersion time.

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Hadisaputra, Saprizal, Zohrul Iskandar e Dina Asnawati. "Prediction of the Corrosion Inhibition Efficiency of Imidazole Derivatives: A Quantum Chemical Study". Acta Chimica Asiana 2, n. 1 (15 febbraio 2019): 88. http://dx.doi.org/10.29303/aca.v2i1.15.

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This study aims to determine the the efficiency of corrosion inhibition of imidazole derivatives in carbon steel based on quantum chemical parameters. Density functional theory method was applied in this study. Corrosion inhibition efficiency values are strongly influenced by substituent groups. Corrosion inhibition efficiency values have a linear correlation with quantum chemical parameters. The amine substituent increased the value of corrosion inhibition efficiency, in contrast nitro group reduced the efficiency of corrosion inhibition. The predicted corrosion inhibition efficiency data of imidazole does agree with the experimental data.

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Bazzi, L., E. Azzouyahar e M. Essahli. "Investigation of the Effect of Natural Extract on Corrosion Behavior of Tin in Na2CO3 Solution". JOURNAL OF ADVANCES IN CHEMISTRY 5, n. 3 (24 aprile 2017): 800–809. http://dx.doi.org/10.24297/jac.v5i3.6593.

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The inhibition effect of eugenol oil (EO) on the corrosion of tin in 0.1 M Na2CO3 has been studied by electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization technics. The effect of temperature on the corrosion behavior of tin in 0.1 M Na2CO3 with and without addition of eugenol oil was studied in the temperature range 278-308 K. This compound inhibits the corrosion of tin at low concentration. At 4g/L eugenol oil the inhibition efficiency calculated by potentiodynamic polarization and EIS techniques is 70% and 82%, respectively. The inhibition efficiency increased with increase of the inhibitor concentration and decreased with increase of medium temperature. Electrochemical impedance spectroscopy was used to investigate the mechanism of corrosion inhibition. Polarization curves reveal that EO acts as a mixed-type inhibitor in corrosive solution. The results obtained from the different corrosion evaluation techniques are in good agreement.

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Umoren, S. A., U. M. Eduok e M. M. Solomon. "Effect of polyvinylpyrrolidone – polyethylene glycol blends on the corrosion inhibition of aluminium in HCl solution". Pigment & Resin Technology 43, n. 5 (26 agosto 2014): 299–313. http://dx.doi.org/10.1108/prt-09-2013-0079.

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Purpose – The purpose of this paper is to investigate the effect of polyethylene glycol (PEG), polyvinylpyrrolidone (PVP) and blended formulations on the corrosion inhibition of aluminium in HCl solutions at 30-60°C and to study the mechanism of action. Design/methodology/approach – The inhibitive effect of the homopolymers and polymer blend was assessed using weight loss and hydrogen evolution methods at 30 and 60°C. The morphology of the corroding aluminium surface without and with the additives was visualized using atomic force microscopy. The trend of inhibition efficiency with temperature was used to propose the mechanism of inhibition and type of adsorption. Findings – Results obtained show that inhibition efficiency (η%) increases with increase in concentration of the polymers but decreases with increase in temperature. The inhibition efficiency of the homopolymers and their blends decreased with rise in temperature. Inhibition efficiency was found to be synergistically enhanced on blending the two homopolymers with highest inhibition efficiency obtained for (PEG:PVP) blending ratio of 1:3. The phenomenon of physical adsorption is proposed from the trend of inhibition efficiency with temperature. Research limitations/implications – The mechanistic aspect of the corrosion inhibition can be better understood using electrochemical studies such as potentiodynamic polarization and electrochemical impedance spectroscopy. Originality/value – Studies involving the use of polymer blends/mixtures as corrosion inhibitor for metals in corrosive environments are scarce. The results suggest that the mixture could find practical application in corrosion control in aqueous acidic environment. The data obtained would form part of database on the use of polymer–polymer mixtures to control acid-induced corrosion of metal.

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Kawahara, Yuuzou, Kouji Sasaki e Yuuji Nakagawa. "Development and Application of High Cr-High Si-Fe-Ni Alloys to High Efficiency Waste-To-Energy Boilers". Materials Science Forum 522-523 (agosto 2006): 513–22. http://dx.doi.org/10.4028/www.scientific.net/msf.522-523.513.

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In order to improve the durability of high efficiency waste-to-energy boilers, it is essential to develop and apply high temperature corrosion-resistant materials having a long life time according to the intensity of the corrosion conditions. Two types of high Cr-high Si-Fe-Ni base and high Cr-high Si-Ni-Fe base alloy seamless tubes; MAC-N (26Cr-3.5Si-11Fe-Ni base) alloy and MAC-F (23Cr-3.8Si-38Ni-Fe base) alloy respectively which contain no expensive Mo and have better corrosion resistance than the existing alloys under severe corrosive environments of waste combustion gas, have developed. The optimum alloy composition range were defermined by confirming the effect of the alloying elements on the corrosion resistance in the laboratory corrosion tests. Furthermore, the seamless tubes were mounted on the actual superheater of the 500oC/9.8MPa high efficiency waste-to-energy boiler to examine the durability over a period of four years. As a result, it was confirmed that the MAC-N and MAC-F alloys have better corrosion resistance than the Alloy625 and 310HCbN. In addition, it has become clear that corrosion resistance of both alloys is displayed through the formation of SiO2 rich protective scale due to the combined addition of the principal elements, Si, Cr, Fe and Ni. Under conditions of high Cl content molten deposits and severe thermal cycle, the corrosion rate increases as the results of deterioration of protective oxidation scale.

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Mohyaldinn, Mysara Eissa, Wai Lin, Ola Gawi, Mokhtar Che Ismail, Quosay A. Ahmed, Mohammed A. Ayoub e Anas Hasan. "Experimental Investigation of a New Derived Oleochemical Corrosion Inhibitor". Key Engineering Materials 796 (marzo 2019): 112–20. http://dx.doi.org/10.4028/www.scientific.net/kem.796.112.

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Most of the corrosion inhibitors that are used in industry contain chemicals that are harmful to health and environment. Corrosion inhibitors derived from green sources are, therefore, believed to be a good option for replacing the chemical corrosion inhibitors. In this work, a green oleochemical corrosion inhibitor derived from Jatropha Curcas is introduced. The paper discusses the methodology of deriving the corrosion inhibitor as well as the experimental test conducted for evaluating its corrosion inhibition efficiency. The new oleochemical corrosion inhibitor was derived via two reactions. Jatropha oil was firstly saponified with sodium hydroxide to yield gras acid and glycerol, which was then esterified with boron fluoride in presence of excess methanol to produce the oil methyl esters, which is used as oleo-chemical corrosion inhibitor. To evaluate the oleo-chemical corrosion inhibitor, the corrosion rate of mild steel in NaCl corrosive medium with CO2 is tested at static condition and two dynamic conditions, namely 500 and 1500 rpm. This is to simulate the transitional and turbulent flow in a pipeline. At each dynamic condition, the proposed corrosion inhibitor was tested at concentration dosages of 0, 50, 100, and 150 ppm. The experiments results revealed a good performance of the new oleochemical corrosion inhibitor. The inhibition efficiency was found to be highly affected by the concentration of corrosion inhibitor. Total corrosion inhibition of the mild steel was noticed by using 150 ppm at dynamic condition of 500 rpm.

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Martínez, I., C. Andrade, N. Rebolledo, L. Luo e G. De Schutter. "Corrosion-Inhibitor Efficiency Control: Comparison by Means of Different Portable Corrosion Rate Meters". Corrosion 66, n. 2 (1 febbraio 2010): 026001–026001. http://dx.doi.org/10.5006/1.3319663.

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Abstract Corrosion-inhibiting substances have been applied to suppress corrosion mainly on bare steel, but when corrosion is progressing, suppression can be achieved if anodic and cathodic reactions are avoided, which is not an easy objective, particularly if the bare metal is surrounded by concrete. In the present article, several corrosion inhibitors are studied to identify their inhibition efficiency in concrete. The percentage of reduction of the corrosion rate without and with inhibitor is named “inhibition efficiency.” This definition calls for the measurement of the corrosion rate and makes its measurement a must when studying corrosion-inhibiting substances. The most extended technique used for the corrosion rate quantification is based on the calculation of the polarization resistance, Rp. For the study presented in this article, several portable corrosion rate meters based on the Rp technique have been used. These equipment are needed for the evaluation of large structures and are able to confine the current in small areas or to determine the steel area affected by the signal for a correct corrosion rate calculation. A comparison among the different corrosion rate meters used for the inhibitor's efficiency has been done. This comparison has indicated that the corrosion rate meter with nonefficient confinement of the current is not able to detect clearly the passivation state.

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Kaščák, Luboš, Janette Brezinová e Jacek Mucha. "Evaluation of Corrosion Resistance of Galvanized Steel Sheets Used in Automotive Production". Materials Science Forum 818 (maggio 2015): 141–44. http://dx.doi.org/10.4028/www.scientific.net/msf.818.141.

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The steel sheets used for the car body production are protected against corrosion by zinc coating. Resistance spot welding is used mainly for joining these sheets, because of its high speed and adaptability for automation in high-rate production. However, resistance spot welding has a negative influence on the corrosion resistance of joints. The paper focuses on the analysis of quality of welds on galvanized steel sheets and their corrosive properties. Tensile test and accelerated corrosion test in corrosive environment were used for evaluation of the welds’ quality. Protective efficiency of zinc coatings for automobile sheets was evaluated as well, based on the determination of their electrochemical characteristics in passivated and non-passivated state, as well as their corrosion resistance in simulated corrosion environments. Two types of DX54D+Z material were used for experiments: non-passivated and passivated with Cr3+.

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Septiyani Arifin, Devi Eka, Destri Muliastri, Rudi Rudiana e Fitri Nur Indah Sari. "Green Corrosion Inhibitors to Head Off the Corrosion Rate of ST 37 Steels". Current Journal: International Journal Applied Technology Research 2, n. 1 (21 maggio 2021): 21–28. http://dx.doi.org/10.35313/ijatr.v2i1.40.

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The corrosions process is a natural process and cannot be hindered, but it can be protected by adding a green inhibitor. Green corrosion inhibitors are a new alternative solution for corrosion protection because they are low-cost, biodegradable, and eco-friendly inhibitors. This research was used papaya leaves dan guava leaves extract as organic inhibitor solution by Maceration Method. The concentration of these green inhibitors is 0 mL, 1 mL, 2.5 mL, 3 mL, and 3.5 mL. The type of testing method used in this research is FTIR, PDP, and weight loss. The results show that there is Tanin function groups in papaya leaves and guava leaves extract. The potentiodynamic polarization shows the value of corrosion rate without inhibitor is 0,418 mm/year. In contrast, the corrosion rate was decreased with improving the green inhibitor as many 3.5 mL. The corrosion rate was decreased until 0,00055 mm/year, and the value of efficiency is 99,868%.

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Jiang, Quan, Yu Jun Liu e Ru Ping Liu. "Durability Assessment of Hot Dip Galvanized Reinforcement Concrete". Advanced Materials Research 177 (dicembre 2010): 533–36. http://dx.doi.org/10.4028/www.scientific.net/amr.177.533.

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Treat the steel bars by hot dip galvanizing technology to prepare steel concrete specimen. Adopt artificial accelerated corrosion test to simulate the seawater corrosive environment in continuous immersion zone and tidal zone and carry out accelerated corrosion for the concrete bars. Add NaCl whose cement content is 1%, 5% and 7% respectively in the concrete specimen to improve the chloride ion content in the system and simulate the strong corrosion environment. This thesis examines the corrosion influence of chloride ion penetration on the ordinary bars and hot-dip steel bars. It also assesses the corrosion protection efficiency for hot dip galvanized reinforcement (HDGR) by half cell method and analyzes the test results.

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Rajendran, S., S. Vaibhavi, N. Anthony e D. C. Trivedi. "Transport of Inhibitors and Corrosion Inhibition Efficiency". CORROSION 59, n. 6 (giugno 2003): 529–34. http://dx.doi.org/10.5006/1.3277584.

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Rajkumar, D., e D. Prasannan. "Comparative Studies on Inhibitor Efficiency in Mild Steel and Iron". International Journal of Engineering & Technology 7, n. 2.24 (25 aprile 2018): 130. http://dx.doi.org/10.14419/ijet.v7i2.24.12017.

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Metals generally corrode mild steel is an alloy form of from which undergoes corrosion easily in acidic medium. The corrosion products are formed when a metal give its electrons to the oxidizing substances, the organic compounds containing sulphur, nitrogen and oxygen are known to be effectiveness depends on the electron density at the functional groups. We need to reduce the corrosion of steel by adding inhibitor. Tensile strength of steel varies depends on the corrosion. Thus, the aim of this project is to determine the inhibitor efficiency of thiourea, urea, and hydroquinone for the corrosion of normal steel and iron in common HCL medium consists of different concentration of inhibitor.

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Wajdi, Farid, Saprizal Hadisaputra e Iwan Sumarlan. "Benzimidazole corrosion inhibition performance: A DFT Study". Acta Chimica Asiana 1, n. 2 (15 agosto 2018): 43. http://dx.doi.org/10.29303/aca.v1i2.27.

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The corrosion inhibition performance of benzimidazole and its derivatives have been studied by density functional theory DFT in aqueous medium. For this investigation, the corrosion inhibition efficiencies of the protonated and non-protonated spesies of benzimidazole and its derivatives were investigated. The ionization potential of the inhibitors has a strong influence on the efficiency of corrosion inhibitors. The linear correlation was shown between electronic properties and corrosion inhibition efficiency. Electron donating substituents increase the corrosion inhibition efficiency, whereas electron withdrawing substituents give the opposite effect. The NH2 substituent contributes highest, whereas NO2 provides the weakest contribution to the corrosion inhibition efficiency for both non-protonated and protonated species of inhibitors.

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Slaiman, Qasim J. M., Basim O. Hasan e Hayder M. Turki. "Performance Of some Corrosion Inhibitors For Carbon Steel In Hydrochloric Acid". Journal of Petroleum Research and Studies 3, n. 1 (6 maggio 2021): 48–68. http://dx.doi.org/10.52716/jprs.v3i1.63.

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Corrosion tests on commercial carbon steel pipe in aerated 0.1N HCl solution under static and flow conditions with ranges of rotation velocity of 400–1400 rpm and temperature of 35 – 60ºC, were carried out by weight loss method, in absence and presence of several inhibitors which were thiourea, ethylenediamine, diethano-lamine and formaldehyde as an adsorption type inhibitors in concentration range 400 – 2000 ppm using rotating cylinder arrangement. The experimental results showed that the corrosion rate in absence and presence of inhibitors is increased with the increasing temperature of the corrosive solution and the rotational velocity and is decreased with increasing the inhibitors concentration for the whole range of temperatures and rotational velocities. Highest inhibition efficiency was attained by thiourea with considerable efficiencies for other inhibitors. The order of corrosion inhibitors efficiencies was as follows: thiourea > ethylenediamine > diethanolamine > formaldehyde. Under static conditions maximum inhibition efficiency obtained was 77.59% for thiourea and the minimum inhibition efficiency was 37.12% for formaldehyde depending on inhibitor concentration and temperature. Also the results revealed that the inhibitors efficiency increases with increasing its concentration and decreases with increasing agitation speed and temperature. The thiouurea was found to be good inhibitor even at high agitation velocity while the formaldehyde failed to inhibit corrosion at high velocity.

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Wang, You Qiang. "Experimental Study of the Corrosion Behaviors on the Rod and Tube Material in Oil Pumping Wells". Advanced Materials Research 239-242 (maggio 2011): 1790–93. http://dx.doi.org/10.4028/www.scientific.net/amr.239-242.1790.

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To study the corrosion behaviors on the rod and tube materials used in oil well is very important for prolonging oil well repairing periods, lowering oil production maintenance costs and increasing oil production efficiency. Through selecting some kinds of tube and rod materials which are always used in oilfield, chemical corrosion experiment and electrochemical corrosion experiment were carried out under different conditions. The results show that the corrosion rates are accelerated with material prestress increasing, liquid mineralization rate and temperature rising. The nitrified materials have better corrosive resistance than untreated materials. The electrochemical corrosion experiment results show that the electrode potentials of four materials (45, 20CrMo, J55, N80) have tiny difference and don’t exceed 20mV. The bimetallic corrosion tests show that the couple corrosion of the four selected materials pair can be ignored under short period and oxygen conditions.

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Ngobiri, N. C., e C. Obi. "Corrosion Inhibition Behaviour of Enantia chlorantha Extract on Pipeline Steel Corrosion in Acidic System". Journal of Applied Sciences and Environmental Management 24, n. 4 (22 maggio 2020): 707–12. http://dx.doi.org/10.4314/jasem.v24i4.24.

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The corrosion inhibition capacity of Enantia chlorantha bark (ECB) extract on the corrosion of pipeline steel in an acidic environment was studied using the gravimetric method. The result revealed that weight loss obviously increased with the rise in temperature though trend lines were not parallel. The results obtained from the evaluation showed that the corrosion inhibition efficiency of the extract increased with extract concentrationattaining an efficiency of 89.02% with 2.5 g/L concentration at 30 ºC. The corrosion inhibition efficiency, however, decreased with increase in temperature, while the corrosion rate decreased. The significant achievement in this study was the ability of Enantia chlorantha extract to reduce the corrosion rate constant, increase its surface coverage with consequent longer material half-life in an acidic environment. Keywords: Inhibition efficiency, surface coverage, plant extract, weight loss, half-life

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Yin, Cheng Xian, Juantao Zhang, Zhen Quan Bai e Bin Wei. "Effect of Corrosion Inhibitor TG201 on Electrochemical Corrosion Behavior of Tubular Steel HP13Cr". Applied Mechanics and Materials 229-231 (novembre 2012): 155–58. http://dx.doi.org/10.4028/www.scientific.net/amm.229-231.155.

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This paper studies effect of corrosion inhibitor TG201 on electrochemical corrosion behavior of tubular steel HP13Cr by polarization curve test and exchange impedance spectrum method. It analyzes corrosion morphology by SEM. The results show that the increase of compression stress on HP13Cr lead to its self-corrosion potential shifting negatively, then electrochemical corrosion rate increases. Finally, corrosion resistance performance of HP13Cr steel weakens in acidification environment. Effects of compression stress on electrochemical corrosion become weak by adding TG201 inhibitors. And inhibitor efficiency of TG201 has obvious increase. So controlling compression stress has certain influence on inhibitors efficiency.

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Sri Hermawan, Yuli Rizky Ananda Nasution e Rosdanelli Hasibuan. "PENENTUAN EFISIENSI INHIBISI KOROSI BAJA MENGGUNAKAN EKSTRAK KULIT BUAH KAKAO (Theobroma cacao)". Jurnal Teknik Kimia USU 1, n. 2 (25 dicembre 2012): 31–33. http://dx.doi.org/10.32734/jtk.v1i2.1415.

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Cocoa peel extract is a natural inhibitor that can be used to inhibit the corrosion reaction rate. This research begins by extracting cocoa pods by maceration followed by evaporation on rotary vacuum evaporator and extracts used as the inhibitor with concentration 600, 800 and 1000 ppm, using steel 1 × 2 cm and the thickness is 0,1 cm to determine the corrosion rate and corrosive medias are sea water, rainwater and sulfuric acid 1 M . The highest inhibition efficiency generated is 93,06% with concentration of 600 ppm inhibitor in rainwater corrosive media; which means that cocoa peel extract more efficiently used in rainwater corrosive media.

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Yuli Rizky Ananda Nasution, Sri Hermawan e Rosdanelli Hasibuan. "PENENTUAN EFISIENSI INHIBISI REAKSI KOROSI BAJA MENGGUNAKAN EKSTRAK KULIT BUAH MANGGIS (Garcinia mangostana L)". Jurnal Teknik Kimia USU 1, n. 2 (25 dicembre 2012): 45–48. http://dx.doi.org/10.32734/jtk.v1i2.1418.

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Abstract (sommario):

Garcinia mangostana peel extract is a natural inhibitor that can be used to inhibit the corrosion reaction rate. This research begins by extracting Garcinia Mangostana pods by maceration followed by evaporation and extracts used as the inhibitor with concentration 600, 800 and 1000 ppm, with the test sample of corrosion is steel 1 × 2 cm with the thickness is 0,1 cm and corrosive medias are sea water, rain water and sulfuric acid 1 M. The highest inhibition efficiency generated is 99,22% with ethanol solvent at concentration of 800 ppm inhibitor in rain water corrosive media; which means that Garcinia mangostana peel extract more efficiently used in rain water corrosive media.

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Langston, Lee S. "Gems of Turbine Efficiency". Mechanical Engineering 136, n. 09 (1 settembre 2014): 76–77. http://dx.doi.org/10.1115/9.2014-sep-9.

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This article discusses the use of turbine single-crystal blades in gas turbines. Single-crystal turbine blades were first used in military engines on Pratt’s F100 engine, which powered the F16 and F15 fighter aircrafts. Their first commercial use was on P&WA’s JT9D-7R4 engine, which received FAA certification in 1982, powering Boeing’s 767 and the Airbus A310. In jet engines, single-crystal turbine airfoils have proven to have as much as nine times more relative life in terms of creep strength and thermal fatigue resistance and over three times more relative life for corrosion resistance, when compared to equiaxed crystal counterparts. Modern high turbine inlet temperature jet engines with long life would not be possible without the use of single-crystal turbine airfoils. By eliminating grain boundaries, single-crystal airfoils have longer thermal and fatigue life, are more corrosion resistant, can be cast with thinner walls, and have a higher melting temperature. These improvements all contribute to higher gas turbine thermal efficiencies.

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31

Al-Rubaiey, Najem A., Fadhil S. K. Kadhim e Mohamed G. Alb Albrazanjy. "The Effect of Adding Carboxymethyl Cellulose and Zinc Sulfate on the Corrosion Characteristics of the Drilling Fluid". Al-Khwarizmi Engineering Journal 15, n. 1 (1 marzo 2019): 125–33. http://dx.doi.org/10.22153/kej.2019.08.003.

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Drilling solutions can be considered as an intricate mixture comprising of number of chemical additives which aid specific needs such as controlling the rheological properties and reducing corrosion. Inhibitors are substances that are added in small concentrations to corrosive environment to decrease the corrosion. Their applications can be found in drilling equipments. The effect of adding Zinc Sulphate and Carboxymethyl Cellulose to study their influence on the corrosion of carbon steel in Bentonite mud has been evaluated using Weight Loss Technique. This study focuses on determining rheological properties and corrosion characteristics. Results show CMC and ZnSO4 work as inhibitors when added to the Bentonite with inhibition efficiency was approximately equal to 50%.

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Hassan, Refat, Ishaq Zaafarany, Adil Gobouri e 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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Reddy, V. Srinivasa, Polina VVSSSR Krishna, G. Sai Karthik e S. Shrihari. "Assessment of Corrosion Inhibiting Efficiency of Microbes Induced Concrete". E3S Web of Conferences 184 (2020): 01114. http://dx.doi.org/10.1051/e3sconf/202018401114.

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The study present in this paper reveals the corrosion inhibiting efficiency of M25 grade concrete induced with Sporosarcina pasteurii bacteria. The accelerated corrosion induced crack method is applied on reinforced bacterial concrete which is the modified philosophy of constant voltage technique. In the current investigation, for different cover thicknesses considered, total time required for charge passed until full longitudinal crack occurs along the cover thickness due to corrosion of steel reinforcement in concrete specimens are measured using which Charge Deterioration Factors (ChDFs) are evaluated for bacterial reinforced concrete beams made with various cell concentrations of Sporosarcina pasteurii bacteria. It was established that beams made with cell concentration of 105 cells/ml of mixing water offers superior corrosion inhibition ability as time taken to form full length longitudinal crack is more than in other beams made with 103 cells/ml, 104 cells/ml and 106 cells/ml cell concentration of bacteria chosen for the study.

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A. Jawad, Qusay, Dhafer S. Zinad, Rawaa Dawood Salim, Ahmed A Al-Amiery, Tayser Sumer Gaaz, Mohd S. Takriff e Abdul Amir H. Kadhum. "Synthesis, Characterization, and Corrosion Inhibition Potential of Novel Thiosemicarbazone on Mild Steel in Sulfuric Acid Environment". Coatings 9, n. 11 (4 novembre 2019): 729. http://dx.doi.org/10.3390/coatings9110729.

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Corrosion of a material by reaction with a corrosive environment is a common problem across many industries. Iraq is an oil country and corrosion represents a large portion of the total costs for oil producing and a natural potential hazard associated with oil production and transportation. The synthesis of novel thiosemicarbazone, namely 2-(2,4-dimethoxybenzylidene)hydrazinecarbothioamide (DMBHC), was conducted and the chemical structure was elucidated via the 1H and 13C NMR (Nuclear magnetic resonance), and FT-IR (Fourier-transform infrared) spectroscopic spectroscopic techniques in addition to carbon, hydrogen, and nitrogen analyses (CHN analyses). The inhibition properties of the investigated thiosemicarbazone were evaluated for mild steel (MS) corrosion in 1N H2SO4 using electrochemical impedance spectroscopy (EIS), weight loss method, and scanning electron microscopy (SEM). Electrochemical and weight loss techniques revealed that the tested thiosemicarbazone acted as a superior inhibitor for the acidic corrosion of MS and the efficiency increased with increasing concentrations. The EIS results revealed that thiosemicarbazone demonstrated the highest inhibition efficiency of 94.86%, at a concentration of 0.5 mM. Results from the weight loss technique suggested that the thiosemicarbazone acted as a mixed type corrosion inhibitor. The impact of temperature on the mechanism of inhibition of the new synthesized inhibitor of the surface of MS in 1N H2SO4 was investigated at various temperatures (30–60 °C) where the inhibitive efficiency diminished with increasing temperatures. The mechanism of inhibition was additionally verified with the methodological data.

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Kulkarni, Prateek, Charitha B. Ponnappa, Partha Doshi, Padmalatha Rao e Seetharaman Balaji. "Lignin from termite frass: a sustainable source for anticorrosive applications". Journal of Applied Electrochemistry 51, n. 10 (13 luglio 2021): 1491–500. http://dx.doi.org/10.1007/s10800-021-01592-8.

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AbstractThe present study reports a sustainable source of lignin, from termite frass. Lignin was extracted using Klason’s method and subjected to polarization studies to check the inhibition efficiency and measured the electrochemical performance of the coated sample on the carbon steel using electrochemical impedance spectroscopy. The anticorrosive property was determined in a simulated corrosive environment (0.1 M NaOH and 0.5 M NaOH). The morphological analysis of the surface of both bare metal and the lignin-coated ones, before and after exposure to the corrosive environment, was recorded using atomic force microscopy (AFM), scanning electron microscopy (SEM), and energy-dispersive X-Ray spectroscopy (EDX). The lignin showed maximum inhibition efficiency at 600 ppm in 0.5 M NaOH solution. Moreover, the lignin coated on carbon steel exhibited about 70% corrosion inhibition efficiency as recorded by potentiodynamic polarization studies and electrochemical impedance spectroscopy. The AFM and SEM analyses further corroborated the protection of the metal surface from corrosion when coated with lignin. Hence, the study suggests lignin from termite frass as a sustainable biological source suitable for anticorrosive applications. Graphic abstract

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36

Al-Amiery, Ahmed, Lina M. Shaker, Abdul Amir H. Kadhum e Mohd S. Takriff. "Synthesis, characterization and gravimetric studies of novel triazole-based compound". International Journal of Low-Carbon Technologies 15, n. 2 (6 gennaio 2020): 164–70. http://dx.doi.org/10.1093/ijlct/ctz067.

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Abstract 4-Amino-3-(2-bromo-5-methoxyphenyl)-1H-1,2,4-triazole-5(4H)-thione (ATH) was synthesized and characterized by nuclear magnetic resonance and Fourier-transform infrared as spectroscopical techniques and elemental analysis. ATH was studied for corrosion inhibition of mild steel in corrosive environment by means of weight loss technique, scanning electron microscopy and the adsorption isotherm. ATH demonstrates a superior inhibition efficiency against corrosion of mild steel. Adsorption data fit well to a Langmuir isotherm model.

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Wu, Ming, Juan Qin Xue, Li Hua Yu, Xiao Na Ma e Jun Zhu. "Scale and Corrosion Inhibition Efficiency of a Novel Terpolymer". Materials Science Forum 658 (luglio 2010): 185–88. http://dx.doi.org/10.4028/www.scientific.net/msf.658.185.

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A terpolymer AA-HPA-SVS was synthesized from acrylic acid (AA), 2-hydroxypropyl acrylate (HPA) and sodium vinyl sulfonate (SVS) by following a free radical polymerization procedure. The scale and corrosion inhibition efficiency and dispersion ability of the terpolymer were studied. The results showed that the AA-HPA-SVS terpolymer had good antiscaling properties towards calcium carbonate and calcium phosphate, and good dispersion ability towards ferric oxide. The scale inhibiting efficiency of the terpolymer can reach to 95% and 93% for CaCO3 and Ca3(PO4)2 respectively when the dosage was 20mg/L. Its corrosion inhibition efficiency towards carbon steel was improved greatly when sodium molybdate was added. When 150mg/L sodium molybdate dehydrate was added to 20 mg/L terpolymer, the corrosion inhibition rate can reach to 85%.

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Yasakau, K. A., M. L. Zheludkevich e M. G. S. Ferreira. "Lanthanide Salts as Corrosion Inhibitors for AA5083. Mechanism and Efficiency of Corrosion Inhibition". Journal of The Electrochemical Society 155, n. 5 (2008): C169. http://dx.doi.org/10.1149/1.2844341.

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39

Shekhter, Yu N., V. V. Egorov, A. Ya Furman, N. V. Kardash e Yu V. Kuznetsov. "Efficiency of oil-soluble corrosion inhibitors under conditions of corrosion and mechanical stress". Chemistry and Technology of Fuels and Oils 22, n. 1 (gennaio 1986): 14–17. http://dx.doi.org/10.1007/bf00736110.

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40

Fan, Baomin, Gang Wei, Zhan Zhang e Ning Qiao. "Preparation of supramolecular corrosion inhibitor based on hydroxypropyl-β-cyclodextrin/octadecylamine and its anti-corrosion properties in the simulated condensate water". Anti-Corrosion Methods and Materials 61, n. 2 (25 febbraio 2014): 104–11. http://dx.doi.org/10.1108/acmm-04-2013-1256.

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Purpose – This work was focused upon the main factors that influence the formation of a hydroxypropyl-β-cyclodextrin (HP-β-CD) supramolecular complex with octadecylamine (ODA) and their optimal processing conditions. The anti-corrosion properties of the products in the simulated boiler water condensate of power plants also needed to be tested. The paper aims to discuss these issues. Design/methodology/approach – A grinding method was applied to synthesize the supramolecular structures. Using Fourier transform infrared, X-ray diffraction and proton nuclear magnetic resonance spectroscopy (1H NMR), the specific structures of the complex were clarified. The anti-corrosion properties were obtained from gravimetric results, potentiodynamic polarization tests and electrochemical impedance spectroscopy measurements. Findings – The results reveal the highly soluble supramolecular complex could be formed between two HP-β-CD molecules and one ODA molecule at 85°C with a processing period of 15 minutes. In the condensate, the corrosion inhibition efficiency of the complex was over 95 percent, much higher than the inhibition efficiency of the hydrophobic ODA compound. Practical implications – The supramolecular corrosion inhibitor could be used as an anti-corrosion method for industrial boiler condensate to reduce the content of corrosive ions. In this way, it is easier to reuse the condensate without re-polishing. Originality/value – The research introduces supramolecular chemistry into corrosion science for the first time. The results provide a new option to modify the traditional corrosion inhibitors.

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Patel, Jasbir N., Andre Chang, Haleh Shahbazbegian e Bozena Kaminska. "Adaptive Corrosion Protection System Using Continuous Corrosion Measurement, Parameter Extraction, and Corrective Loop". International Journal of Corrosion 2016 (2016): 1–11. http://dx.doi.org/10.1155/2016/9679134.

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A simple current-sourced adaptive corrosion protection system (ACPS) along with a technology to extract the protection current from the Tafel plot is presented. For reliable protection of the target metal, first, the Tafel plot of the target metal is obtained. Subsequently, a novel technique proposed in this paper is used to extract the protection current from the Tafel plot. This extracted protection current is fed to the target metal to protect the metal in the existing corrosive environment. This three-part system is adaptively used to update the required protection current to effectively protect the target metal continuously. All these functionalities are integrated in a stand-alone ACPS that effectively diagnoses the corrosion status and updates the protection parameters without any manual interaction or physical modification of the set-up to offer modularity, reliability, and cost saving. To validate the technique, a laboratory scale system is realized and tested using various metal samples and various corrosive mediums. Using the experimental system, A36 metal coupons are effectively protected with protection (inhibition) efficiency of 40–100%in different corrosive mediums that can extend the life expectancy of the target metal from ~2 times to more than 100 times for the tested corrosive mediums.

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Sobral, A. V. C., e César V. Franco. "Study of Corrosion Resistance of Sintered Fe-2%Ni, Fe-5%Ni and Fe 10%Ni with Electroactive Polymeric Coating of Poly trans-[RuCl₂(vpy)₄]". Materials Science Forum 530-531 (novembre 2006): 78–84. http://dx.doi.org/10.4028/www.scientific.net/msf.530-531.78.

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The use of generated coated polymeric films by electrochemistry means in the sintered metallic surfaces has been being the focus of our research aimed at the corrosion protection of small mechanical components obtained from powder metallurgy. The sintered alloys Fe- 2%Ni, Fe-5%Ni and 10%Ni with polymeric coating were tested using electrochemistry methods in corrosive solutions of NaCl 3%, KNO3 1.25M, H2SO4 0.5M, HNO3 0.5M, acetic acid 1%, oxalic acid 1% and lactic acid 1%. The electrochemistry corrosion tests were performed using two techniques, Eocp vs. Time and Potentiodynamic and they proved the efficiency of the polymeric coating on the corrosion protection of sintered alloys.

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Sezer, Esma, e İpek Öztürk. "Mild steel protection with tannic and polyaspartic acid in cooling systems". Anti-Corrosion Methods and Materials 66, n. 5 (2 settembre 2019): 583–94. http://dx.doi.org/10.1108/acmm-04-2019-2105.

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Purpose Tannic acid (TA) is one of the green corrosion inhibitors for mild steel; its anti-corrosive performance in alkaline water on mild steel when it is used together with polyaspartic acid (PASA) still has not been investigated. The purpose of this study is to develop an effective, biodegradable and environment-friendly novel corrosion inhibitor based on TA and PASA as an alternative to the conventional inorganic inhibitors for mild steel in decarbonised water, which is common in cooling systems. Design/methodology/approach Corrosion inhibition mechanism is investigated by electrochemical techniques such as polarisation measurements and electrochemical impedance spectroscopy, and results were evaluated to determine the optimum inhibitor concentration for industrial applications. Additionally, practice-like conditions are carried out in pilot plant studies to simulate the conditions in cooling systems. Thus, the efficiencies of the inhibitors are evaluated through both weight loss and linear polarisation resistance measurements. Moreover, the corrosion product is characterised by scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX) and Fourier-transform infrared spectroscopy (FTIR) analysis. Findings TA shows high inhibition efficiency especially towards pitting corrosion for mild steel in decarbonised water. PASA addition in the cooling systems improves the inhibition efficiency of TA, and at lower concentrations of TA + PASA, it is possible to obtained better inhibition efficiency than TA alone at higher inhibitor amounts, which is essential in economic and environmental aspect. Originality/value A blended inhibitor program including TA and PASA with suggested concentrations in this work can be used as an environmental friendly treatment concept for the mild steel corrosion inhibition at cooling systems.

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Pradityana, Atria, Subowo, Hari Subiyanto, Eddy Widiyono e Dwi Winarto Gathot. "Application of Seeds from Psidium Guajava as Organic Inhibitor". Key Engineering Materials 867 (ottobre 2020): 103–8. http://dx.doi.org/10.4028/www.scientific.net/kem.867.103.

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Corrosion is the process of natural changes in the nature of a material due to the influence or reaction with the surrounding environment. One way to control it is by adding inhibitors. In this study, seeds from guava (Psidium Guajava) were used as organic inhibitors. The test material used is API 5L grade B steel. For corrosive media, a solution of 1 M H2SO4 is used. In experiments used variations in the concentration of extracts 0, 2, 3, 4, 5 and 6 ml. The results of the experiments showed a decrease in the corrosion rate of API 5L grade B when there were additional inhibitors. This is supported by the experimental results of Potentiodynamic Polarization. The rate of corrosion without the presence of an inhibitor shows 75,018 mmpy whereas in the presence of 2,8845 mmpy inhibitors. Based on the calculation, the inhibition efficiency is 96.155%. This is also indicated by the results of the testing of weight loss that has been done. The efficiency shown is 90.130%.

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Istiqlaliyah, Hesti, e Prila Candrama. "Utilization of cigarette clove, tobacco leaf, and coffee as iron inhibitor". Jurnal Mesin Nusantara 1, n. 1 (25 giugno 2018): 1. http://dx.doi.org/10.29407/jmn.v1i1.12290.

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Corrosion is an event of metal degradation due to reaction to the environment. One way to prevent corrosion is to use inhibitors. This inhibitor can prevent the rate of corrosion of metals by providing a coating on the metal of an extract of organic material having N, S, O, P atoms with the aid of solvents and in the heat process. This study aims to determine the effect of inhibitor material variations on corrosion rate on iron, and to know which inhibitors are more efficient to prevent the rate of corrosion. The research method used is experimental method that is weight loss with the result of data analysis using analysis of variance in software minitab 17. The result of research shows that there is influence to the variation of inhibitor material on the decrease of corrosion rate. From the research results obtained data which inhibitor more efficient to prevent corrosion, tobacco leaf has average corrosion rate of 0,000049 gram / cm2 hour and efficiency of equal to 43,40%, while for coffee decrease of average corrosion rate is 0, 000158 gram / cm2 hour and its efficiency is 23.26%, while the clove cigarette has an average corrosion rate of 0,000094 gram / cm2 hours and efficiency 33,34%. We can see that the most efficient inhibitor is from tobacco extract with the lowest corrosion rate and the greatest efficiency.

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Nossoni, G., e R. Harichandran. "Current Efficiency in Accelerated Corrosion Testing of Concrete". CORROSION 68, n. 9 (settembre 2012): 801–9. http://dx.doi.org/10.5006/0428.

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Lukovits, I., E. Kálmán e F. Zucchi. "Corrosion Inhibitors—Correlation between Electronic Structure and Efficiency". CORROSION 57, n. 1 (gennaio 2001): 3–8. http://dx.doi.org/10.5006/1.3290328.

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48

Briggs, Tobinson, e obioma M. Eseonu. "Efficiency of Corrosion Inhibitors on Cathodic Protection System". International Journal of Engineering Trends and Technology 8, n. 3 (25 febbraio 2014): 113–26. http://dx.doi.org/10.14445/22315381/ijett-v8p222.

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49

Maiko, L. P., A. B. �nglin, I. A. Prokop'ev, N. N. Zakharova, Yu N. Shekhter e �. V. Kalinina. "Prediction of protective efficiency of corrosion-preventive compounds". Chemistry and Technology of Fuels and Oils 26, n. 8 (agosto 1990): 436–39. http://dx.doi.org/10.1007/bf00725706.

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Zhang, Xin, Xue Dong Wu, Jian Zhong Li, Hui Wang, Dan Dai e Zhen Lun Song. "Anticorrosion Behaviors of Quaternary Polyethyleneimine in Acidic Environment". Materials Science Forum 610-613 (gennaio 2009): 136–41. http://dx.doi.org/10.4028/www.scientific.net/msf.610-613.136.

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Polymeric compounds are of great interest as corrosion inhibitors in acidic environment due to their inherent stability. Polymeric film is effectively used for the protection of metals partly owing to their capacity to act as a physical barrier between the metal surface and the corrosive environment. In this paper, a cation polyelectrolyte inhibitor (Quaternary Polyethyleneimine, QPEI) was prepared. The quality and inhibition efficiency of QPEI self-adsorbed films were studied by polarization curve and electrochemical impedance spectroscopy, respectively. The compositions and morphologies of the polymer film on the steel surface were examined with the aids of SEM and XPS, respectively. The results showed that QPEI could greatly retard the corrosion of iron in sulfuric acid, which was attributed mainly to the protective QPEI film formed on the surface. Meanwhile, the inhibition of QPEI could be supposed as a mixed process, in which both cathodic and anodic corrosions were simultaneously restrained. Based on the results of XPS and SEM, it could be evidenced that the QPEI can form a protective polymer layer on the metal surface by adsorption.

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