Inhibition Effects of Some Organic Compounds on Zinc Corrosion in 3.5% NaCl

2008 ◽  
Vol 59 (5) ◽  
Author(s):  
Viorel Branzoi ◽  
Alina Pruna ◽  
Florina Branzoi

The inhibition of zinc corrosion in 3.5% NaCl solution by some organic compounds (sodium dodecylsulphate (SDS), sodium dodecylbenzosulphonate (SDBS) and sodium 1,4-bis(2-etylhexyl) sulphosuccinate (AOT)) was investigated. The inhibition efficiencies were determined by polarization measurements of the zinc electrode in the solution. Electrochemical impedance spectroscopy (EIS) was also used for electrochemical studies of zinc electrode in this medium. The results showed that the used surfactants inhibit the cathodic reaction of hydrogen evolution and at low anodic overvoltage the corrosion process is under activation control, while at high anodic overvoltage the process is under diffusion control.

2017 ◽  
Vol 744 ◽  
pp. 380-384
Author(s):  
Hui Tong ◽  
Wen Li Han ◽  
Zhong Ping Xu ◽  
Yan Jun Zhang ◽  
Zhu Lin ◽  
...  

Electrochemical impedance spectroscopy (EIS) is a technology of nondestructive electrochemical testing. In this paper, EIS is applied to study the corrosion processes of Al-Mg coatings. In the initial 24 h of immersion in 3.5% NaCl solution, passive films of Al-Mg coatings dissolve quickly. As time passed, corrosion products increase on surface gradually, which can inhibit corrosion. After 480h of immersion, corrosion products fully cover on Al-Mg coatings’ surface. The EIS of different corrosion processes are fitted by three equivalent circuits corresponding to the three corrosion processes. In the test of open circuit potentials (OCP), OCP is instable in the initial 24 h of immersion. As immersion time goes by, OCP tends to stabilization at about -0.90 V. Measurements of scanning electron microscope (SEM) confirm the conclusions of electrochemical measurements.


2013 ◽  
Vol 652-654 ◽  
pp. 1432-1435
Author(s):  
Qian Hu ◽  
Jing Liu ◽  
Jie Zhang ◽  
Feng Huang ◽  
Xing Peng Guo

The crevice corrosion behaviors of X52 carbon steel in two typical Cl--containing solutions were investigated by electrochemical noise and electrochemical impedance spectroscopy. Results show that oxygen concentration difference leads to the coupled current in NaCl + NaHCO3 solution while HAc concentration difference causes the coupled current in NaCl solution saturated with CO2 in the presence of HAc. There exists an apparent incubation stage during the crevice corrosion process of X52 carbon steel in the former. However, no obvious incubation period of crevice corrosion can be observed in the latter. Micrography shows that the crevice corrosion occurs indeed and the corrosion inside the crevice is not uniform.


2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Atria Pradityana ◽  
Sulistijono ◽  
Abdullah Shahab ◽  
Lukman Noerochim ◽  
Diah Susanti

Inhibitor is a substance that is added to the corrosive media to inhibit corrosion rate. Organic inhibitors are preferred to inorganic ones since they are environmentally friendly. One of the organic compounds which is rarely reported as a corrosion inhibitor isMyrmecodia Pendans. The organic compounds can be adsorbed on the metal surface and block the active surface to reduce the rate of corrosion. In this study, the used pipe was carbon steel API 5L Grade B with 3.5% NaCl solution as the corrosion medium. The objective of this research was to analyze the inhibition mechanismMyrmecodia Pendanstowards carbon steel in a corrosion medium. Concentration variations of extractMyrmecodia Pendanswere 0–500 ppm. Fourier Transform Infrared (FTIR) was used for chemical characterization ofMyrmecodia Pendans. Polarization and Electrochemical Impedance Spectroscopy (EIS) were used to measure the corrosion rate and behaviour. From the electrochemical measurements, it was found that the addition of 400 mg/L inhibitor gave the highest inhibition efficiency.Myrmecodia Pendansacted as a corrosion inhibitor by forming a thin layer on the metal surface.


2018 ◽  
Vol 2018 ◽  
pp. 1-20 ◽  
Author(s):  
Vanessa Mandarano Pinela ◽  
Leandro Antônio de Oliveira ◽  
Mara Cristina Lopes de Oliveira ◽  
Renato Altobelli Antunes

The AZ91D magnesium alloy was immersed in 3.5 wt.% NaCl solution at room temperature for times ranging from 1 minute up to 72 hours. The aim was to investigate the evolution of the corrosion process using confocal laser scanning microscopy (CLSM), electrochemical impedance spectroscopy, and X-ray photoelectron spectroscopy. The microstructure of the as-received alloy was initially characterized by optical microscopy and scanning electron microscopy (SEM). The crystalline phases were identified by X-ray diffractometry. The main phases were primary-α, eutectic-α, and β (Mg17Al12). Vickers microhardness markings were made on the surface of one etched sample to facilitate the identification of the same region at each different immersion time, thus enabling the observation of the corrosion process evolution. Corrosion initiates at the grain boundaries of the eutectic microconstituent and, then, propagates through primary α-grains. The β-phase was less severely attacked.


2015 ◽  
Vol 11 (6) ◽  
pp. 3642-3655 ◽  
Author(s):  
O. A Abdullatef

Azithromycin has been tested as inhibitor for steel, copper and zinc corrosion in 0.5 M H2SO4 was studied using potentiodynamic polarization and electrochemical impedance spectroscopy.  The results showed that the inhibition efficiency increased with increasing the concentration of Azithromycin. The adsorption characteristics of Azithromycin in presence of steel, copper and zinc metals were studied and the data  found to fit the Kinetic-Thermodynamic model. IR spectroscopy of the corrosion product with the inhibitor confirmed the formation of metal ion inhibitor complex.


2013 ◽  
Vol 83 (5) ◽  
pp. 864-869 ◽  
Author(s):  
Elisa J. Kassab ◽  
José Ponciano Gomes

ABSTRACT Objective: To assess the influence of fluoride concentration on the corrosion behavior of nickel titanium (NiTi) superelastic wire and to compare the corrosion resistance of NiTi with that of beta titanium alloy in physiological solution with and without addition of fluoride. Materials and Methods: NiTi corrosion resistance was investigated through electrochemical impedance spectroscopy and anodic polarization in sodium chloride (NaCl 0.15 M) with and without addition of 0.02 M sodium fluoride (NaF), and the results were compared with those associated with beta titanium. The influence of fluoride concentration on NiTi corrosion behavior was assessed in NaCl (0.15 M) with and without 0.02, 0.04, 0.05, 0.07, and 0.12 M NaF solution. Galvanic corrosion between NiTi and beta titanium were investigated. All samples were characterized by scanning electron microscopy. Results: Polarization resistance decreased when NaF concentration was increased, and, depending on NaF concentration, NiTi can suffer localized or generalized corrosion. In NaCl solution with 0.02 M NaF, NiTi suffer localized corrosion, while beta titanium alloys remained passive. Current values near zero were observed by galvanic coupling of NiTi and beta titanium. Conclusions: There is a decrease in NiTi corrosion resistance in the presence of fluoride. The corrosion behavior of NiTi alloy depends on fluoride concentration. When 0.02 and 0.04 M of NaF were added to the NaCl solution, NiTi presented localized corrosion. When NaF concentration increased to 0.05, 0.07, and 0.12 M, the alloy presented general corrosion. NiTi corrosion resistance behavior is lower than that of beta titanium. Galvanic coupling of these alloys does not increase corrosion rates.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Yucong Ma ◽  
Mohd Talha ◽  
Qi Wang ◽  
Zhonghui Li ◽  
Yuanhua Lin

Purpose The purpose of this paper is to study systematically the corrosion behavior of AZ31 magnesium (Mg) alloy with different concentrations of bovine serum albumin (BSA) (0, 0.5, 1.0, 1.5, 2.0 and 5.0 g/L). Design/methodology/approach Electrochemical impedance spectroscopy and potential dynamic polarization tests were performed to obtain corrosion parameters. Scanning electrochemical microscopy (SECM) was used to analyze the local electrochemical activity of the surface film. Atomic force microscope (AFM), Scanning electron microscope-Energy dispersive spectrometer and Fourier transform infrared spectroscopy were used to determine the surface morphology and chemical composition of the surface film. Findings Experimental results showed the presence of BSA in a certain concentration range (0 to 2.0 g/L) has a greater inhibitory effect on the corrosion of AZ31, however, the presence of high-concentration BSA (5.0 g/L) would sharply reduce the corrosion resistance. Originality/value When the concentration of BSA is less than 2.0 g/L, the corrosion resistance of AZ31 enhances with the concentration. The adsorption BSA layer will come into being a physical barrier to inhibit the corrosion process. However, high-concentration BSA (5.0 g/L) will chelate with dissolved metal ions (such as Mg and Ni) to form soluble complexes, which increases the roughness of the surface and accelerates the corrosion process.


2004 ◽  
Vol 151 (3) ◽  
pp. B179 ◽  
Author(s):  
S. J. Xia ◽  
R. Yue ◽  
R. G. Rateick ◽  
V. I. Birss

Author(s):  
Caio A. J. da Silva Da Silva ◽  
Lilian N. M. Braguin ◽  
Larissa O. Berbel ◽  
Bárbara V. G. De Viveiros ◽  
Jesualdo L. Rossi ◽  
...  

Currently, magnesium alloys are gaining great interest for medical applications due to their degrading properties in the human body ensuring a great biocompatibility. These alloys also provide profitable mechanical properties due similarities with human bone.  However, a difficulty in applying these materials in the biomaterials industries is the corrosion prior to cell healing. The effect of the chemical composition of Mg alloys on their corrosion behavior is well known. In this study, samples of AZ31 magnesium alloy were cut into chips for elemental chemical analysis by neutron activation analysis (NAA). Concentrations of the elements As, La, Mg, Mn, Na, Sb and Zn were determined in the AZ31 alloy. Visualization tests of agar corrosion development in various media, of 0.90% sodium chloride solution (mass), phosphate buffer saline (PBS) and simulated body fluid (SBF) were performed. Visualizations of the effect of agar gel corrosion revealed pH variation during the corrosion process due to the released into the cathode. The highest released of hydroxyl ions occurred in NaCl solution compared to PBS and SBF solutions indicating that NaCl solution was much more aggressive to the alloy compared to the others.


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