M. Abdallah

Rhodanine azosulpha drugs as corrosion inhibitors for corrosion of 304 stainless steel in hydrochloric acid solution

Abstract The effect of rhodanine azosulpha drugs on the corrosion behaviour of 304 stainless steel in 1.0 M hydrochloric acid solution as corrosive medium has been investigated using weight loss and potentiostatic polarization techniques. Some corrosion parameters such as anodic and cathodic Tafel slope, corrosion potential, corrosion current, exchange current densities, surface coverage and inhibition efficiency were calculated. The polarization measurements indicated that the inhibitors are of mixed type and inhibit corrosion by parallel adsorption on the surface of steel due to the presence of more than one active centre in the inhibitor molecule. The adsorption is obeyed Langmuir adsorption isotherm. The activation energy and thermodynamic parameters were calculated at different temperature.

Natural honey as corrosion inhibitor for metals and alloys. II. C-steel in high saline water

The inhibtive action of natural honey on the corrosion of C-steel, which used in manufacturer of petroleum pipelines, in high saline water was evaluated. The inhibition efficiency was calculated using weight loss measurements and potentiostatic polarization technique. It was found that, natural honey exhibited a very good performance as inhibitor for steel corrosion in high saline water. The inhibition efficiency increases with an increase in natural honey concentration. After some time, the inhibition efficiency decreased due to the growth of fungi in the medium. The adsorption of natural honey on the C-steel was found to follow the Langmuir adsorption isotherm.

Ethoxylated fatty alcohols as corrosion inhibitors for dissolution of zinc in hydrochloric acid

The effect of some ethoxylated fatty alcohols, with different numbers of ethylene oxide units, on the corrosion of zinc in 0.5 M HCl has been studied using weight loss and polarization measurements. The inhibition efficiency was found to increase with increasing concentration, number of ethylene oxide units per molecule and with decreasing the temperature. Inhibition was explained on the basis of adsorption of ethoxylated fatty alcohols molecules on the metal surface through their ethoxy groups. The degree of surface coverage varied linearly with logarithm of inhibitor concentration fitting Temkin isotherm. The thermodynamic parameters were calculated for the tested system from the data obtained at different temperatures.

INHIBITION OF CARBON STEEL CORROSION BY SOME CYANOACETOHYDRAZIDE DERIVATIVES IN HCl SOLUTION

This article describes an investigation of the corrosion behavior of carbon steel in 2 M HCl solution with the addition of some cyanoacetohydrazide derivatives by weight loss, galvanostatic polarization, and potentiodynamic anodic polarization techniques. The explored methods gave almost similar results. Results obtained reveal that inhibitor (I) is the best inhibitor and the inhibition efficiency (IE%) follows the sequence I > II > III > IV. The percentage inhibition efficiency was found to increase with increasing concentration of inhibitors and decreases with increasing temperature of the medium. The addition of KI, KSCN, and KBr to cyanoacetohydrazide derivatives enhanced the inhibition efficiency due to synergistic effect. The effect of temperature on C-steel corrosion in 2 M HCl and with the addition of 11 × 10−6 M of investigated compounds in the temperature range 30°–50°C was studied. Some thermodynamic functions were computed and discussed. The inhibitors are adsorbed on the carbon steel surface according to Temkins adsorption isotherm. Polarization data suggested that the additives used act as mixed-type inhibitors. It was found that the cyanoacetohydrazide derivatives provide good protection to carbon steel against pitting corrosion in chloride-containing solutions.

INHIBITION OF ACIDIC AND PITTING CORROSION OF NICKEL USING NATURAL BLACK CUMIN OIL

The inhibition effect of natural black cumin oil on the corrosion of nickel in 0.1 M HCl solution was studied using galvanostatic and potentiodyanmic anodic polarization techniques. It was found that the inhibition efficiency increased with an increase in the inhibitor concentration of this oil. The inhibitive action of black cumin oil was attributed to the adsorption on metal surface. The adsorbed layer acts as a barrier between the metal surface and aggressive solution, leading to a decrease in the corrosion rate. The adsorption process follows the Langmuir adsorption isotherm. It was found also that black cumin oil provides good protection to nickel against pitting corrosion in sodium chloride solutions.

INHIBITION OF THE CORROSION OF NICKEL AND ITS ALLOYS BY NATURAL CLOVE OIL

The corrosion behavior of nickel, Inconel 600, and Inconel 690 in different concentrations of HCl solutions and its inhibition by clove oil was studied using potentiostatic polarization measurements. As the acid concentration increases, the rate of corrosion increases, indicating that HCl accelerates the dissolution of nickel and its alloys. The inhibition efficiency of the clove oil was found to increase with increase of its concentration. The inhibitive action of this oil was discussed in view of adsorption onto the metal surface. The adsorbed layer acts as a barrier between the metal surface and aggressive solution, leading to a decrease in corrosion rate. The adsorption process follows Langmuir adsorption isotherms. It was found that the clove oil provides good protection to nickel and its alloys against pitting corrosion in chloride-containing solution using potentiodynamic anodic polarization techniques.

Some organic and inorganic compounds as inhibitors for carbon steel corrosion in 3.5 percent NaCl solution

Purpose – To study the effects of the sodium salts of molybdate, tungstate and monovanadate as well as some derivatives of Neville‐Winter acid azo dyes on the corrosion of carbon steel in 3.5 percent NaCl solution.Design/methodology/approach – Open circuit potential measurement and potentiostatic polarization techniques have been used.Findings – It was found that all the compounds had inhibition effects on carbon steel dissolution. Inhibition efficiency (IE) increased with increase in inhibitor concentration. The process of inhibition was attributed to the formation of an adsorbed film on the metal surface, which protects the metal against the corrosive medium. The adsorption of these compounds on the steel/chloride interface was found to follow Freundlich adsorption isotherm behaviour.Originality/value – Proves the effectiveness of the sodium salts of molybdate, tungstate and monovanadate as well as some derivatives of Neville‐Winter acid azo dyes on the corrosion of carbon steel in 3.5 percent NaCl solu...

Phenazone and aminophenazone as corrosion inhibitors for aluminum in HCl solution

The corrosion behavior of aluminum in 1 M HCl solution in the absence and presence of phenazone and aminophenazone was investigated using weight loss, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques. The results of these techniques show that, the inhibition efficiency of these compounds depends on their concentration and chemical structure. The inhibitive action of these compounds was discussed in terms of blocking the electrode surface by adsorption of the molecules through the active centers contained in their structure. The adsorption process was found to obey Temkin isotherm model. The effect of temperature on the rate of corrosion in the absence and presence of these compounds was also, studied. Some activated thermodynamic parameters were computed and discussed. Potentiodynamic polarization data indicated that these compounds act as cathodic type inhibitors. From impedance data it is found that the corrosion of aluminum is controlled by charge transfer process at all concentrations of inhibitors. Quantum chemical parameters were constructed in order to characterize the inhibition performance of the tested molecules.

Adsorption and inhibition effect of novel cationic surfactant for pipelines carbon steel in acidic solution

A new cationic surfactant was prepared and examined as an inhibitor for the corrosion of carbon steel in 1.0 M HCl solution using weight loss measurements, electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization measurements. The chemical structure of the prepared cationic surfactants has been proven by FTIR spectra. The inhibiting effect of the cationic surfactant as a result of the formation of the protective layer adsorbed on the carbon steel surface The adsorption of the inhibitor was discussed accordingly to the Langmuir isotherm. Polarization data indicated that the cationic surfactant is a mixed-type inhibitor.. The effect of temperature on the corrosion rate of carbon steel in1. 0 M HCl solution devoid of and containing the novel cationic surfactant was examined and thermodynamic parameters were computed. Some surface parameters were calculated and explained.

Synthesis of some aromatic nitro compounds and its applications as inhibitors for corrosion of carbon steel in hydrochloric acid solution

The inhibition effect of some synthetic aromatic nitro compounds on the corrosion of carbon steel in 1 M HCl solution was studied using galvanostatic and potentiodynamic anodic polarization measurements. The percentage inhibition efficiency was found to increase with increasing the concentration of inhibitors and decreasing of temperature. Polarization data indicated that the additives acted as mixed-type inhibitors meaning that these compounds reduced the anodic dissolution of carbon steel and retard the cathodic hydrogen evolution reaction. Inhibition was interpreted in view of formation of insoluble complex adsorbed on the metal surface. The formation of complex was confirmed by UV-spectra. The adsorption of these compounds was found to obey Langmuir adsorption isotherm. Activation energy and some activated thermodynamic parameters were computed and discussed. It was found that these additives provide good protection to carbon steel against pitting corrosion in chloride-containing solution.