Synergistic effect p-phenylenediamine and n,n diphenylthiourea on the electrochemical corrosion behaviour of mild steel in dilute acid media

Electrochemical studies of the synergistic effect of p-phenylenediamine and n,n diphenylthiourea (TPD) as corrosion inhibitor of mild steel in dilute sulphuric and hydrochloric acid through weight loss and potentiodynamic polarization at ambient temperature were performed. Experimental results showed the excellent performance of TPD with an optimal inhibition efficiency of 88.18 and 93.88 %in sulphuric and 87.42 and 87.15 %in hydrochloric acid from both tests at all concentration studied. Polarization studies show the compound to be a mixed-type inhibitor. Adsorption of deanol on the steel surface was observed to obey the Langmuir and Frumkin isotherm models. X-ray diffractometry confirmed the absence of corrosion products and complexes. Optical microscopy confirmed the selective inhibition property of TPD to be through chemical adsorption on the steel surfac

Corrosion inhibition of steel in sulfuric acidic solution by the Chenopodium Ambrosioides Extracts

The influence of natural occurring extract of Chenopodium Ambrosioides (CAE) on the corrosion inhibition of carbon steel in sulfuric acid solution is studied by the weight loss method, potentiodynamic polarization and impedance spectroscopy (EIS) measurements. The experimental results reveal that extract has a good inhibiting effect on the metal tested in 0.5 M H2SO4 solution. The protection efficiency increases with increasing inhibitor concentration to attain 94% at 4 g/l. Potentiodynamic polarization studies clearly reveal that it acts essentially as a cathodic inhibitor. EIS results show that the change in the impedance parameters (Rt and Cdl) with concentration of extract of Chenopodium Ambrosioides is indicative of the adsorption of molecules leading to the formation of a protective layer on the surface of carbon steel. The efficiency decreases with temperature. The adsorption of Chenopodium Ambrosioides extract is found to obey the Langmuir adsorption isotherm. The activation energies and enthalpies of the corrosion process of carbon steel in acidic medium were determined

Inhibition of carbon steel corrosion in 1 M HCl medium by potassium thiocyanate

The effect of potassium thiocyanate (KSCN) on the corrosion of carbon steel (C-steel) in 1 M HCl has been investigated in relation to the concentration of the inhibitor by polarization curves, electrochemical impedance spectroscopy and weight loss measurement. The results obtained revealed that this compound is a good mixed type inhibitor with predominant cathodic effectiveness. The effect of temperature on the corrosion behavior with the addition of optimal concentration of KSCN was studied in the temperature range 298–328 K. The value of inhibition efficiency decreases slightly with the increase in temperature. Changes in impedance parameters (charge transfer resistance, Rct, and double layer capacitance, Cdl) were indicative of adsorption of KSCN on the metal surface, leading to the formation of a protective film. Adsorption of KSCN on the C-steel surface was found to obey the Langmuir adsorption isotherm. Some thermodynamic functions of dissolution and adsorption processes were also determined and discussed

Performance of a new pyrazole derivative in 1 M HCl on the corrosion of carbon steel: experimental, quantum chemical and molecular dynamics simulation studies

The present research demonstrates an innovative investigation of a new pyrazol derivative (2-benzoyl-4-nitro-N-[(1H-pyrazol-1-yl)methyl]aniline (BNPMA)) as an inhibitor of carbon steel corrosion in molar hydrochloric acid. A variety of methods and techniques were used in our research to assess corrosion inhibition, including weight loss measurements (WL), electrochemical trials like potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS), surface analysis methods such a scanning electron microscope coupled with Energy-Dispersive X-ray Spectroscopy (SEM/EDX), UV-Visible analysis, as well as computational evaluation of BNPMA. The organic compound was confirmed to be a good anticorrosive product with a maximal inhibition efficiency (IE%) of 93.2% at 10−3 M. According to the PDP results, the inhibitor BNPMA acts as a mixed-type inhibitor. The Langmuir model seems to be followed during BNPMA's adsorption on the CS surface. According to UV-visible and scanning electron microscopy, a barrier coating was formed which prevented corrosive ions from reaching the CS surface. The outcomes of experimental approaches (WL, PDP, and EIS) have been supported by theoretical investigations.</p