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The purpose of this paper is to study the corrosion inhibition of carbon steel (CS) using a “green” inhibitor, polyvinyl pyrrolidone (PVP), in an aerated, alkaline medium containing 0.1M NaCl (blank) at pH 9 and pH 10. The effects of some additives, such as KI and untreated Saudi clay (UC) were investigated.

Weight loss method, surface studies, electrochemical impedance spectroscopy (EIS) and potentiodynamic polarisation were applied.

The inhibition efficiencies of blank solutions with 1000 ppm PVP ranged from 66‐78% for weight loss results and from 23‐66% for the electrochemical tests. The EIS results indicated that the adsorption of PVP led to the formation of a protective film on the metal/solution interface. Tafel results indicated that PVP is a mixed‐type inhibitor. The addition of KI to PVP and the blank solution significantly increased inhibition efficiency, while the addition of UC reduced the inhibition efficiency. Adding KI resulted in a high surface‐area coverage ranging from about 91% after one hour to about 81% after 45 hours. The adsorption mechanism was fitted with a Langmuir isotherm.

This is a static study, whereas in oil drilling there is a dynamic system; however the findings may apply to both systems.

Carbon steel is used in alkaline and neutral media in the petroleum industry. The effect of KI additives was examined.

The paper shows how it may be possible to reduce the cost of repair of equipment and lower the environmental impact of corrosion.

There are few studies which investigate the combining effect of polymer and KI in alkaline medium containing NaCl.

This paper seeks to study the corrosion rate (CR) of Al 6063 in aqueous solutions containing food additives, namely ascorbic, citric and tartaric acids with/without chloride ions.

Chemical and electrochemical measurements were used to study the CR of Al 6063 in aerated aqueous solutions. Chemical measurements include weight loss (WL) and atomic absorption (AA). The surface morphology of Al 6063 was studied using scanning electron microscope connected with energy dispersion X‐Ray (EDX). Electrochemical measurements were made using a potentiostat/galvanostat; the effect of pH, temperature and immersion time was studied.

AA gave comparable results to that of WL. EDX results showed the depletion of Mg and Fe from the Al 6063 to carboxylic acid solutions w/without NaCl. From electrochemical measurements, it was found that addition of chloride ions to carboxylic acids increased the CR of Al 6063 especially at low pH and high temperatures but it reduced the CR at long immersion times.

Aluminum (Al) is now known to be a neurotoxin agent yet Al cook wares are widely used in different countries. The acids used in this study are food additives which implies that the Al cook wares may corrode in food containing these acids and other carboxylic acids depending on pH, temperature and the presence of other additives.

AA gave comparable results to that of WL, which shows that it may be used to evaluate leaching metal ions in μg levels or less in corrosion measurements.

The inhibition effect of Foeniculum vulgare seeds’ (FVS) extract on the corrosion of mild steel in acidic medium was studied using weight loss, electrochemical impedance spectroscopy and Tafel polarization, as well as the surface morphology of the mild steel.

Weight loss measurements, potentiodynamic tests, electrochemical impedance spectroscopy studies and gas chromatography/mass spectrometry and scanning electron microscopy analysis of FVS extract were performed.

FVS extract acts as a good inhibitor for the corrosion of mild steel in 1.0 M HCl. The inhibition efficiency increases with the increase in inhibitor concentration but decreases with the increase of temperature.

FVS extract was observed to play an important role in the corrosion inhibition of mild steel in acidic solution.

This paper is intended to be added to the family of green inhibitors which are highly efficient inhibitors and can be used in the area of corrosion prevention and control.