Influence of metal cations on inhibitor performance of gluconates in the corrosion of mild steel in fresh water

2018 ◽  
Vol 36 (1) ◽  
pp. 105-113 ◽  
Author(s):  
Kyohei Otani ◽  
Masatoshi Sakairi ◽  
Md. Saiful Islam

AbstractThe influence of metal cations on the ability of gluconates to inhibit corrosion of mild steel in a model fresh water was investigated by electrochemical impedance spectroscopy (EIS) and immersion tests. The EIS and immersion test results showed that the corrosion inhibition of mild steel in model fresh water by gluconates was improved by metal cations that have a large value of corrosion inhibitory effect of cation, Y. The X-ray photoelectron spectroscopy (XPS) analysis showed that metal cations that have larger Y values are bonded on mild steel. It was thought that metal cations with large Y values and gluconates confer a synergistic inhibition effect on the corrosion of mild steel in model fresh water.

2015 ◽  
Vol 62 (3) ◽  
pp. 143-148 ◽  
Author(s):  
Guohao Chen ◽  
Lingyun Li ◽  
Jian Ouyang ◽  
Zhuoyan Zhu ◽  
Feng Wang ◽  
...  

Purpose – The aim of the present paper was to investigate the inhibition performance of the OF and/or IM on L360 steel in CO2/H2S environments. The pipeline steel surface usually has been pre-treated before using in the oil/gas field, such as by passivation, blackening, and phosphiding. The effectiveness of inhibition can vary because there are many differences between the metal matrix and the treated film. Design/methodology/approach – Imidazoline (IM) was synthesized by using oleic acid and diethylenetriamine, and its composition was verified using Fourier transform infrared spectroscopy. The oxide film (OF) covering a sample of L360 steel was characterized using X-ray diffraction, and its surface morphology was observed using scanning electron microscope. Electrochemical impedance spectroscopy measurements were conducted to study the inhibition performance of IM- and/or OF-covered L360 steel in the CO2/H2S environments. Findings – The results show that IM and OF can prevent corrosion on L360 steel in CO2/H2S environments, and the synergistic inhibition effect of IM and OF was very evident. A possible model is proposed to explain the synergistic inhibition effect in the CO2/H2S environments of IM and OF on L360 steel. Originality/value – Few reports have concerned the effect of the OF on the inhibitor’s performance, especially in CO2/H2S systems. The aim of the present study was to investigate the inhibition performance of the OF and/or IM on L360 steel in CO2/H2S environments. A model is proposed to explain the synergistic inhibition effect mechanism between IM and OF.


2009 ◽  
Vol 16 (01) ◽  
pp. 141-147 ◽  
Author(s):  
A. N. SENTHILKUMAR ◽  
K. THARINI ◽  
M. G. SETHURAMAN

Three piperidin-4-one oxime derivatives viz. 3,5-dimethyl-2,6-diphenyl-piperidin-4-one oxime (DDPO), 3-ethyl-2,6-diphenyl-piperidin-4-one oxime (EDPO), and 1-methyl-3-isopropyl-2, 6-diphenyl-piperidin-4-one oxime (MIDPO) were synthesized. Corrosion inhibiting ability of these compounds in 1 M HCl was studied using weight loss study, potentiodynamic polarization measurements, electrochemical impedance spectroscopy, XRD and SEM with EDS measurements. Weight loss studies revealed that all the three oximes are good corrosion inhibitors. The order of inhibiting ability of these compounds is as follows: DDPO > EDPO > MINDO. Results of the polarization measurement showed that these inhibitors do not alter the mechanism of either hydrogen evolution or mild steel dissolution reaction, proving the mixed mode of inhibition. At constant acid concentration, increase of inhibitor concentration increased the charge transfer resistance (R ct ), complimented with decrease of double layer capacitance (C dl ), thereby indicating the increase of percentage inhibition efficiency. XRD and SEM with EDS analysis provided strong proof for the existence of inhibitor film over the mild steel surface.


2017 ◽  
Vol 893 ◽  
pp. 313-317
Author(s):  
Jin Hu Sun ◽  
Hui Li ◽  
Qing Dong Zhong ◽  
Chen Xiao ◽  
Zhe Rui Huang ◽  
...  

Cu/Zn/Cu multilayer coatings were prepared on mild steel substrates by dual bath technique in order to improve the corrosion resistance of mild steel in seawater. The microstructures of the coated substrates and its resistance to corrosion in simulated seawater were evaluated by scanning electron microscopy (SEM), the brine immersion test and electrochemical impedance spectroscopy (EIS). Salt water immersion test results show that the Cu/Zn/Cu multilayer coatings exhibited the highest corrosion resistance. The red rust spot appeared on the coating surface for the first time when the time of the coating soaked in salt water reached 2520h. The trend of the impedance variation reflected by the electrochemical impedance spectroscopy was the same as the change tendency of corrosion resistance was analyzed by the salt water immersion test. The results of SEM showed that the layer of copper were deposited by round cell structure, the middle layer of zinc coating was flat and compact.


Minerals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 790
Author(s):  
Junbo Liu ◽  
Shuming Wen ◽  
Qicheng Feng ◽  
Qian Zhang ◽  
Yijie Wang ◽  
...  

Sulfide hemimorphite can be depressed by Fe3+ during flotation. In this study, the depression mechanism was studied by microflotation, inductively-coupled plasma mass spectrometry, local electrochemical impedance spectroscopy (LEIS), and X-ray photoelectron spectroscopy (XPS). Flotation test results suggested that sulfated hemimorphite can be depressed by Fe3+ across the entire pH range. LEIS, adsorption analysis, and XPS indicated that S species were adsorbed on hemimorphite as ZnS. The sulfide film was attenuated and no adsorbed Fe species were found after treatment with Fe3+. The results indicate that Fe3+ reacts with the ZnS film, which decreases the number S species, and this leads to hemimorphite depression.


2021 ◽  
Vol 12 (5) ◽  
pp. 6487-6503

The aim of the present work is to investigate the inhibitory effect of the aerial part of Daucus carota L essential oil (EO) on mild steel in a 1.0M HCl solution. The electrochemical study is performed using potentiodynamic polarization (PDP) curves, and electrochemical impedance spectroscopy (EIS) measurements in the presence of various concentrations of the examined Daucus carota L essential oil (EO). PDP results show that the studied EO behaved as a mixed-type inhibitor. EIS measurements indicated that the EO could inhibit the corrosion of mild steel by the formation of a protective film on the surface of mild steel. The experimental results showed an efficiency of 96.5% for a concentration of 2 g/l. In addition, The DFT results proved that the major components, especially -pinene (23.5%), -Bisabolene (3.96%), and Pseudo limonene (7.20%) having a high electron-accepting ability and interact actively with the iron surface, which may be responsible for the inhibition ability of the investigated EO. Furthermore, the computational complies with the experimental data.


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