Studies on the effect of sulphide ions on the inhibition efficiency of chromate on mild steel using radio‐tracer technique

1982 ◽  
Vol 29 (11) ◽  
pp. 8-14 ◽  
Author(s):  
K.D. Maji ◽  
Inder Singh
2019 ◽  
Author(s):  
Chem Int

The corrosion inhibition characteristics of two medicinal molecules phenylalanine and rutin on mild steel in 1.0M Hydrochloric acid were evaluated using gravimetric method. Corrosion inhibition efficiency of 83.78 and 90.40 % was obtained respectively after seven days. However, phenylalanine showed weak accumulative higher corrosion inhibition efficiency. The presence of both molecules in the corrosive environment reduced the corrosion rate constant and increased the material half-life. Thermodynamic data calculated suggests a spontaneous adsorption of the molecules on the mild steel’s surface.


Coatings ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 106
Author(s):  
Akbar Ali Samsath Begum ◽  
Raja Mohamed Abdul Vahith ◽  
Vijay Kotra ◽  
Mohammed Rafi Shaik ◽  
Abdelatty Abdelgawad ◽  
...  

In the present study, the corrosion inhibition effect of Spilanthes acmella aqueous leaves extract (SA-LE) on mild steel was investigated in 1.0 M HCl solution at different temperature using weight loss, Tafel polarization, linear polarization resistance (LPR), and electrochemical impedance (EIS) measurements. Adsorption of inhibitor on the surface of the mild steel obeyed both Langmuir and Temkin adsorption isotherms. The thermodynamic and kinetic parameters were also calculated to determine the mechanism of corrosion inhibition. The inhibition efficiency was found to increase with an increase in the inhibitor concentration i.e., Spilanthes acmella aqueous leaves extract, however, the inhibition efficiency decreased with an increase in the temperature. The phytochemical constituents with functional groups including electronegative hetero atoms such as N, O, and S in the extract adsorbed on the metal surface are found responsible for the effective performance of the inhibitor, which was confirmed by Fourier-transform infrared spectroscopy (FT-IR) and ultraviolet–visible spectroscopic (UV-Vis) studies. Protective film formation against corrosion was confirmed by scanning electron microscopy (SEM), atomic force microscopy (AFM), and contact angle studies. The result shows that the leaves extract acts as corrosion inhibitor and is able to promote surface protection by blocking active sites on the metal.


Author(s):  
Simeon C. Nwanonenyi ◽  
Okoro Ogbobe ◽  
Emeka Emmanuel Oguzie

The corrosion of mild steel in 0.5 M H2SO4acid solution and the inhibition process by wheat starch (WS) was investigated using weight loss and potentiodynamic polarization measurement techniques respectively. Gravimetric results revealed that there is significant reduction in the corrosion rate of mild steel in the presence of inhibited solution compared to blank solution, and also the inhibition efficiency was found to depend on the concentration of the WS. Data on potentiodynamic polarization results confirmed that WS exhibited mixed type inhibition behaviour, though the cathodic effect was more pronounced. The mode of WS adsorption on the corroding metal surface followed Langmuir isotherm model. In addition, the trend of inhibition efficiency with temperature, activation energy and heat of adsorption parameters revealed a strong interaction between the WS constituents and the corroding metal surface, thus indicating that WS lowered the corrosion process by blanketing the mild steel surface through chemical adsorption mechanism. The mechanism of inhibition was discussed in the light of the chemical structure of starch.


Author(s):  
Lalita Saini ◽  
R. K. Upadhyay

Mass loss and Scanning Electron Microscope method (SEM) have been used to study the corrosion inhibition efficiency on mild steel and aluminium using synthesized inhibitors i.e. N-Benzylidene aniline (CI1) and N-Benzylidene 4-methylaniline (CI2) in Trichloroacetic acid (TCAA). Study reveals that both mild steel and aluminium are prone to corrosion in organic acid like TCAA. Out of these two metals, aluminium is more vigorously corroded by the TCAA in comparison to mild steel in same conditions and synthesized inhibitors CI1 and CI2 are almost same effective for mild steel and aluminium.


2019 ◽  
Vol 7 (4.14) ◽  
pp. 168
Author(s):  
N Z. Nor Hashim ◽  
K Kassim ◽  
F H. Zaidon

Two N-substituted thiosemicarbazone derivatives namely as 2-(4-chlorobenzylidene)-N-phenylhydrazinecarbothioamide and 2-benzylidene-N-phenylhydrazinecarbothioamide (L1 and L2, respectively) have been tested as corrosion inhibitors on mild steel in 1 M HCl. The ligands were synthesized and investigated using potentiodynamic polarization (PD) and electrochemical impedance spectroscopy (EIS).  The obtained results indicated that inhibition efficiency, (IE, %) L1 increased with increasing inhibitor concentrations which behaved as a good corrosion inhibitor compared to L2. The synthesized ligands were successfully characterized by melting point, elemental analysis (C, H, N, and S), Fourier-transform infrared spectroscopy (FT-IR) and NMR (1H and 13C) spectroscopy. The excellent inhibition effectiveness for both compounds on mild steel before and after immersion in 1 M HCl solution containing 40 ppm of L1 and L2 were also verified by scanning electron microscope (SEM). Based on potentiodynamic polarization results, it can be concluded that all investigated compounds are mixed-type inhibitors and obey the Langmuir adsorption isotherm. 


Author(s):  
Harish Kumar ◽  
Vikas Yadav

Mild steel is widely used as main raw material in fabrication of equipment, chief material of construction and as weapons. During its storage and transportation conditions, it comes in contact with aggressive environment which leads to decrease in mechanical strength and loss in useful properties. Four different vapor phase corrosion inhibitors (VPCIs) i.e. Benzaimidazole (BIA), Diphenyl amine (DPA), 2-mercapto benzothiazole (MBTA) and N,N-dimethyl aniline (DMA) were tested under different atmospheric conditions at 40 °C by Weight Loss, Eschke test, Salt Spray, SO2 test and SEM techniques. All the four VPCIs show good corrosion inhibition efficiency i.e. 65-96 %. The results obtained from all the four corrosion experiments were supported by SEM images.


Author(s):  
Lebe A. Nnanna ◽  
Wisdom O. John ◽  
Tochukwu E. Esihe ◽  
Kelechi C. Denkoro ◽  
Victor I. Okparaku ◽  
...  

Inhibition effect of Costusafer on mild steel in 0.5 M HCl was studied using gravimetric method at room temperature. It was found out that Costusafer inhibited the corrosion of mild steel in the acidic environment and that the efficiency of inhibition increased as the concentration of the inhibitor in the environment increased. The data was used to test different isotherms and it suited the Langmuir isotherm. A value of -15.995 kJmol-1 was gotten for the ∆Goads. This value showed that the extracts of Costusafer inhibited the corrosion process through physiosorption mechanism. The high value of inhibition efficiency of the extract as the concentration increased in rationalized in terms of the increase in herteroatoms, saponnins and tannins which are present in the extract.


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