Naturally Occurring Organic Substances as Corrosion Inhibitors for mild Steel in Acid Medium: Concentration and temperature effects

✍ Scribed by Dr. M. A. Abdel Rahim; Dr. Hanaa B. Hassan; Dr. M. W. Khalil

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 593 KB
• Volume: 28
• Category: Article
• ISSN: 0933-5137
• DOI: 10.1002/mawe.19970280410

✦ Synopsis

Abstract

Potentiodynamic cathodic and anodic polarization technique was used to study the effect of some common amino acids concentration on the corrosion inhibition of mild steel in H~2~SO~4~. A value of 1.0 × 10^−4^ M represents a critical concentration, for the aliphatic amino acids, above which the corrosion rate increases. The increase of the sulphur‐containing amino acids concentration largely decreases the corrosion rate. A mono‐layer adsorption of the amino acid molecules on the metal surface was proposed with the adsorption behaviour following the Temkin isotherm at 30°C.

The effect of temperature on the corrosion inhibition of amino acids was also studied over the temperature range 25 to 60°C. Values of the apparent activation energy in the range of 42 ‐ 49 kJ mol^−1^ were estimated for the steel corrosion in the inhibited acid solutions.