The effect of cerium salt as an inhibitor in anodising of the2024-T3aluminium alloy was studied.Scanning electronmicroscopy equipped with energy dispersive X-ray spectroscopy was used to study the surface composition ...The effect of cerium salt as an inhibitor in anodising of the2024-T3aluminium alloy was studied.Scanning electronmicroscopy equipped with energy dispersive X-ray spectroscopy was used to study the surface composition of the alloy before andafter surface preparation.A mixed electrolyte of10%sulphuric acid,5%boric acid and2%phosphoric acid containing0.1mol/Lcerium sulphate salt was used as the anodising electrolyte.Sealing treatment was also done in boiling water and molten stearic acid.Electrochemical impedance spectroscopy and salt spray techniques were performed in order to investigate the corrosion behaviourand durability of the oxide films,respectively.It was concluded that the presence of cerium ions in anodising electrolyte resulted inthe increase in homogeneity,the rate of oxide film growth and also the thickness of the oxide layer,owing to the high oxidisingpower of cerium ion.展开更多
The corrosion inhibition of mild steel in 1 mol·L^(-1) hydrochloric acid by N-methyl-2-(2-nitrobenzylidene)hydrazine carbothioamide(MNBHC) was studied using weight loss and electrochemical studies.Results obtaine...The corrosion inhibition of mild steel in 1 mol·L^(-1) hydrochloric acid by N-methyl-2-(2-nitrobenzylidene)hydrazine carbothioamide(MNBHC) was studied using weight loss and electrochemical studies.Results obtained indicate that the inhibitor is effective in hydrochloric acid medium and the efficiency decreases with increase in temperature.Added halide additives improve the efficiency of the inhibitor.The AC impedance studies reveal that the process of inhibition is through charge transfer.Polarization studies indicate the mixed nature of the inhibitor.From the thermodynamic,spectral and surface analyses the nature of adsorption has been found out.The adsorption of the inhibitor on mild steel follows the Langmuir isotherm.展开更多
The inhibition of corrosion of steel in molar hydrochloric acid solution by new synthesized DMI （（3-（3,4-dimethoxyphenyl）isoxazole-5-yl） methanol） compound is studied by weight loss and electrochemical polarizat...The inhibition of corrosion of steel in molar hydrochloric acid solution by new synthesized DMI （（3-（3,4-dimethoxyphenyl）isoxazole-5-yl） methanol） compound is studied by weight loss and electrochemical polarization measurements. The two methods give consistent results. The polarization curves indicate that the DMI compound acts as mixed-type inhibitor. This compound is efficient inhibitor. The inhibition efficiency increases with the increase of inhibitor concentration to reach 96% at 10-3 M for DMI. The temperature effect on the corrosion behavior of steel in 1 M HCI with and without the DMI compound at 10-3 M is studied in the temperature range from 298 to 318 K. The adsorption of inhibitor on the steel surface is found to obey the Frumkin adsorption isotherm model. From the adsorption isotherm, some thermodynamic data for the adsorption process （f, K and △Gads） are calculated and discussed.展开更多
Corrosion is a costly and complicated problem facing mild of Vitex doniana as a corrosion inhibitor for mild steel in HCI medium steel utility. This study investigated the use of ethanol extract Experimental methods u...Corrosion is a costly and complicated problem facing mild of Vitex doniana as a corrosion inhibitor for mild steel in HCI medium steel utility. This study investigated the use of ethanol extract Experimental methods used are gravimetric and thermometric The results showed that corrosion rate decreased as the concentration of ethanol extract of Vitex doniana increased and with decrease in temperature. Vitex doniana extract obeyed Langmuir and Tempkin adsorption isotherm. Physical adsorption was proposed from △G° and Ea. Inhibition efficiency （1%） and the degree of surface coverage （0） were calculated and all indicated that Vitex doniana was a good corrosion inhibitor.展开更多
文摘The effect of cerium salt as an inhibitor in anodising of the2024-T3aluminium alloy was studied.Scanning electronmicroscopy equipped with energy dispersive X-ray spectroscopy was used to study the surface composition of the alloy before andafter surface preparation.A mixed electrolyte of10%sulphuric acid,5%boric acid and2%phosphoric acid containing0.1mol/Lcerium sulphate salt was used as the anodising electrolyte.Sealing treatment was also done in boiling water and molten stearic acid.Electrochemical impedance spectroscopy and salt spray techniques were performed in order to investigate the corrosion behaviourand durability of the oxide films,respectively.It was concluded that the presence of cerium ions in anodising electrolyte resulted inthe increase in homogeneity,the rate of oxide film growth and also the thickness of the oxide layer,owing to the high oxidisingpower of cerium ion.
文摘The corrosion inhibition of mild steel in 1 mol·L^(-1) hydrochloric acid by N-methyl-2-(2-nitrobenzylidene)hydrazine carbothioamide(MNBHC) was studied using weight loss and electrochemical studies.Results obtained indicate that the inhibitor is effective in hydrochloric acid medium and the efficiency decreases with increase in temperature.Added halide additives improve the efficiency of the inhibitor.The AC impedance studies reveal that the process of inhibition is through charge transfer.Polarization studies indicate the mixed nature of the inhibitor.From the thermodynamic,spectral and surface analyses the nature of adsorption has been found out.The adsorption of the inhibitor on mild steel follows the Langmuir isotherm.
文摘The inhibition of corrosion of steel in molar hydrochloric acid solution by new synthesized DMI （（3-（3,4-dimethoxyphenyl）isoxazole-5-yl） methanol） compound is studied by weight loss and electrochemical polarization measurements. The two methods give consistent results. The polarization curves indicate that the DMI compound acts as mixed-type inhibitor. This compound is efficient inhibitor. The inhibition efficiency increases with the increase of inhibitor concentration to reach 96% at 10-3 M for DMI. The temperature effect on the corrosion behavior of steel in 1 M HCI with and without the DMI compound at 10-3 M is studied in the temperature range from 298 to 318 K. The adsorption of inhibitor on the steel surface is found to obey the Frumkin adsorption isotherm model. From the adsorption isotherm, some thermodynamic data for the adsorption process （f, K and △Gads） are calculated and discussed.
文摘Corrosion is a costly and complicated problem facing mild of Vitex doniana as a corrosion inhibitor for mild steel in HCI medium steel utility. This study investigated the use of ethanol extract Experimental methods used are gravimetric and thermometric The results showed that corrosion rate decreased as the concentration of ethanol extract of Vitex doniana increased and with decrease in temperature. Vitex doniana extract obeyed Langmuir and Tempkin adsorption isotherm. Physical adsorption was proposed from △G° and Ea. Inhibition efficiency （1%） and the degree of surface coverage （0） were calculated and all indicated that Vitex doniana was a good corrosion inhibitor.
