scholarly journals Rare Earth-Based Compounds as Inhibitors of Hot-Corrosion Induced by Vanadium Salts

Materials ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 3796
Author(s):  
N.S. Flores-Garcia ◽  
C.D. Arrieta-Gonzalez ◽  
J.J. Ramos-Hernandez ◽  
G.K. Pedraza-Basulto ◽  
J.G. Gonzalez-Rodriguez ◽  
...  

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.

2018 ◽  
Vol 65 (5) ◽  
pp. 451-457 ◽  
Author(s):  
Yanhua Zhu ◽  
Liqiang Zhao ◽  
Pingli Liu ◽  
Ming Yang

Purpose This paper aims to introduce a method to reduce corrosion caused by acidic-oxidized polymer degradant through subsection injection with different inhibitor. Design/methodology/approach This paper introduced a method to reduce corrosion caused by acidic-oxidized polymer degradant through subsection injection with different inhibitor. Findings The experimental results indicated that the influence of pre-corrosion status on corrosion rate and effectiveness of corrosion inhibitor are significant. The corrosion inhibitors in both injection stage inhibited the corrosion process by preventing the contact of corrosive medium and steel surface through formation of a protective film on the surface of N80 steel. The corrosion rate of polymer degradant can be reduced to 0.63 g/m 2 h through subsection injection with different inhibitor. Originality/value This result will increase the production of polymer injection plugging wells through expanding the application of acidic-oxidized polymer degradant.


2011 ◽  
Vol 480-481 ◽  
pp. 443-447
Author(s):  
Yan Hua Wang ◽  
Yuan Yuan Liu

The distributions of corrosion potential and galvanic current of 304 stainless steel under a NaCl droplet were studied by using the wire beam electrode (WBE). It was found that the distributions of the electrochemical parameters were heterogeneous with isolated anodic and cathodic zones appeared randomly. During the corrosion process, the polarity of some anodes changed with the evolution of time. The localized corrosion rate and heterogeneity increased firstly, and then decreased afterward with the increase of time, which can be attributed to the cooperative effects of the aggressive ions and the corrosion products.


2013 ◽  
Vol 864-867 ◽  
pp. 386-389
Author(s):  
Xue Juan Wang ◽  
Hong Hua Ge ◽  
Wei Wei Lin ◽  
Min Zhang

Performance evaluation of three scale and corrosion inhibitors in simulated cooling water according to generating set in a power plant was presented in this paper. The scale and corrosion inhibition performance of the inhibitors were conducted by the methods of the static scale inhibition and rotary coupon tests respectively. The results indicated that 316L stainless steel has low uniform corrosion rate ranging from 0.0042 to 0.0048 mm/a in the simulated cooling water both with and without inhibitors. The drops of hardness in water with No.1 and No.3 inhibitors were slight, and these two inhibitors were of good scale inhibition while No.2 was poor. Keywords: simulated cooling water; scale inhibition; corrosion inhibition; performance evaluation; 316L stainless steel.


2019 ◽  
Vol 2019 ◽  
pp. 1-6 ◽  
Author(s):  
Mohammad Asadikiya ◽  
Yu Zhong ◽  
Mohammad Ghorbani

Three types of corrosion inhibitors consisting of sodium diphosphate (Na2H2P2O7), sodium benzoate (NaC7H5O2), and sodium tetraborate (Na2B4O7) were evaluated to analyze their effectiveness to inhibit the aluminum alloy 3303 (UNS A93303) against corrosion, in water-ethylene glycol (C2H6O2) mixture. Potentiodynamic polarization tests were carried out to study the effect of each chemical. The temperature of solutions was 88°C and the aluminum samples were coupled with five other metals consisting of mild steel, stainless steel, brass, copper, and solder to include the effect of galvanic corrosion. The results showed that sodium diphosphate can effectively protect the aluminum alloy 3303 in comparison with two other chemicals. The effect of thermal shocking on the corrosivity of water-ethylene glycol solution was also investigated. It was indicated that the corrosivity of water-ethylene glycol solution increases because of thermal shocking, which oxidizes the aqueous ethylene glycol. The corrosion rate of aluminum alloy 3303 coupled with the five metals in thermal shocked water-ethylene glycol solution is 142 mpy, while it is 94 mpy in fresh water-ethylene glycol solution.


Author(s):  
O. V. Bessarab ◽  
T. F. Platonova

Because of the metal packaging corrosion, during storage of canned food the quality deteriorates.One of the ways to reduction of quality loss and increase the shelf life of canned products is the use of food additives - corrosion inhibitors. From the literary data it is known that pectin and gelatin are corrosion inhibitors whose action is based on adsorption to the metal surface.Besides the usual gelatin, in the work we used hydrolyzed gelatin, which does not increase in the viscosity of the liquid phase.The aim of the present work was to study the effect of pectin, gelatin and hydrolysed gelatin on the tinplate corrosion rate in the liquid phase of stone fruit compotes (cherries, merries, peaches and plums). The corrosion rate was measured by the method of linear polarization resistance, based on the creating a potential difference between two identical samples of metal and measuring the amperage.The measurements were carried out using the universal automatic corrosion-meter "Expert-004".For all corrosive media, the corrosion rate kinetics is as follows: at the beginning of the test, the maximum corrosion rate of tinplate is observed, which decreases to a stationary value within 24-36 hours. The presence of inhibitors has not effect the kinetics of the process, but the steady-state corrosion rate for the liquid phase of compote from cherries decreased 1.6 - 3 times, for the liquid phase of compote from peaches - by 1.9 times.For the liquid phase of compotes from merries and plums, the application of pectin and hydrolysed gelatin does not has an inhibitory effect.The greatest inhibitory effect for the liquid phase of compotes from cherries is observed when applying 0.5% hydrolyzed gelatin - without an inhibitor, the steady-state corrosion rate of tinplate was 8.3 ?m / year, with the inhibitor - 2.8 ?m / year. According to the results of the study, it was found that in order to reduce quality losses during the storage of stone fruit compotes in a metal package, it is advisable to apply hydrolyzed gelatin in an amount of 0.5% to the mass of the liquid phase.


2021 ◽  
Vol 72 (3) ◽  
pp. 136-143
Author(s):  
Alvaro Arrieta ◽  
Isora Barrera ◽  
Jorge Mendoza

Corrosion is one of the great problems that many industries face and that generates losses of millions of dollars worldwide. The aim of this work was to evaluate the capacity of polyaniline to increase the anticorrosive capacity of a commercial epoxy paint. Polyaniline was chemically synthesized by oxidation with ammonium persulfate and doped with oleic acid. Polyaniline was added to the paint in various concentrations to evaluate its behavior as an additive to improve the anticorrosion capacity on stainless steel samples. An electrochemical characterization by polarization curves and visual observation was carried out to evaluate the anticorrosive behavior of the modified paints. The results showed that the corrosion rate determined from the tafel plot was lower in the steel samples covered with paint and polyaniline. The concentration of 0.8% of polyaniline in the paint showed a corrosion rate 12 times lower than that of the polyaniline-free paint. Additionally, visual observations and measurements of failed area carried out by applying an accelerated corrosion process by immersion in a 3.5% NaCl aqueous solution, allowed determining that, at a time of exposure of 300 h, corrosion inhibition can be achieved 26 times greater with the addition of 0.8% polyaniline. These results allowed to conclude that the addition of polyaniline by means of a simple mixture, significantly improved the anticorrosive protection capacity of a commercial epoxy paint.


Author(s):  
И.А. УСПЕНСКИЙ ◽  
И.В. ФАДЕЕВ ◽  
Ш.В. САДЕТДИНОВ ◽  
С.Н. КУЛИК ◽  
Е.В. МИТРОХИНА

Целью данной работы явилось получение нового эффективного, экологически безвредного ингибитора коррозии из недорогого и недефицитного сырья. Исследована система моноборат натрияформамид-вода при 25 °C, для чего воспользовались методом физико-химического анализа. Получено новое двойное соединение (моноборатнатрийформамид – МБНФ) состава 2NaBO2 – HСONH2 – 2H2 O. Полученные в ходе экспериментов сведения подтверждают получение нового амидоборатного комплекса и позволяют предположить, что он обладает существенными ингибиторными свойствами. Для подтверждения или отклонения гипотезы, что полученное боратное соединение обладает ингибиторными свойствами, гравиметрическим методом было изучено влияние его концентрации на скорость коррозии, ингибиторный эффект и степень защиты стали Ст3 в 3 %-м растворе NaCl. Для опытов использовали образцы размерами 100х25х2 мм из стали Ст3. Установлено, что лучшие ингибиторные свойства МБНФ проявляются при его концентрации 5 г/л в коррозионнойсреде, так как все три показателя, которыми характеризуются ингибиторы коррозии, достигают экстремума при концентрации МБНФ 5 г/л в 3 %-м растворе NaCl: скорость коррозии снижается с 30,32 до 15,36 г/м2 ·ч·10–3, ингибиторный эффект и степень защиты повышаются до 1,93 и 92,1 % соответственно. На основании результатов экспериментов полученное соединение МБНФ можно рекомендовать в качестве эффективного ингибитора в составе противокоррозионных композиций для защиты оборудования животноводческих комплексов и сельскохозяйственных машин в период межсезонного хранения, а также в растворах синтетических моющих средств для мойки деталей при ремонте агрегатов машин с целью повышения их противокоррозионных свойств. he aim of the research was to obtain a new effective, environmentally friendly corrosion inhibitor from inexpensive and non-defi cient raw materials. By the method of physical and chemical analysis, the sodium monoborate - formamide - water system was studied at 25°C. For the experiments, sodium monoborate and formative chemically pure grade were used as starting materials. The formation of a new double compound (monoboratesodiumformamide – MBSF) with the composition 2NaBO2 – HСONH2 – 2H2 O was established. Using IR spectroscopy, data have been obtained that allow us to interpret new amidoborate complexes and predict their effective inhibitory properties. To confi rm or reject the hypothesis that the obtained borate compound has inhibitory properties, the infl uence of its concentration on the corrosion rate, inhibitory effect and degree of protection of St3 steel in a 3% NaCl solution was studied by gravimetric method. For the experiments, we used samples with sizes 100х25х2 mm made of St3 steel. It was found that the best inhibitory properties of MBSF are manifested at a concentration of 5 g/l in a corrosive environment, since all three indicatorsthat characterize corrosion inhibitors reach an extremum at a concentration of MBSF of 5 g/l in a 3% NaCl solution: the corrosion rate decreases from 30.32 to 15.36 g/m²·h · 10–3, the inhibitory effect and the degree of protection increase to 1.93 and 92.1%, respectively. Based on the results obtained, the obtained MBSF compound can be recommended as an effective inhibitor in the composition of anticorrosive compositions for protecting equipment of livestock complexes and agricultural machines during off-season storage, as well as in solutions of synthetic detergents for washing parts when repairing machine assemblies in order to increase their anticorrosive properties .


Alloy Digest ◽  
2001 ◽  
Vol 50 (5) ◽  

Abstract Aluchrom I SE is an oxidation resistant ferritic stainless steel alloyed with aluminum and rare earth elements. Applications include framework for catalytic automobile muffler systems. This datasheet provides information on composition, physical properties, and tensile properties as well as creep. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: SS-823. Producer or source: Krupp VDM.


Alloy Digest ◽  
1998 ◽  
Vol 47 (12) ◽  

Abstract UGIMA 4404 (UGIMA 316L) is identical to UGINE 4404 (AISI 316L) in analysis, corrosion resistance, mechanical properties, and forging and welding ability, but not with respect to machinability. A specific melting process creates inclusions of malleable oxides with a low melting point. The inclusions improve machinability by 20-30% compared with AISI 316L (1.4404) stainless steel. This datasheet provides information on composition and physical properties. It also includes information on corrosion resistance as well as heat treating, machining, and joining. Filing Code: SS-735. Producer or source: Ugine-Savoie.


Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3381
Author(s):  
Gabriela Gąsior ◽  
Jonasz Szczepański ◽  
Aleksandra Radtke

Iron, while attracting less attention than magnesium and zinc, is still one of the best candidates for biodegradable metal stents thanks its biocompatibility, great elastic moduli and high strength. Due to the low corrosion rate, and thus slow biodegradation, iron stents have still not been put into use. While these problems have still not been fully resolved, many studies have been published that propose different approaches to the issues. This brief overview report summarises the latest developments in the field of biodegradable iron-based stents and presents some techniques that can accelerate their biocorrosion rate. Basic data related to iron metabolism and its biocompatibility, the mechanism of the corrosion process, as well as a critical look at the rate of degradation of iron-based systems obtained by several different methods are included. All this illustrates as the title says, what was done within the topic of biodegradable iron-based materials and what more can be done.


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