ISSN: 1813-0410

Keywords : Langmuir adsorption isotherm


Investigation of the Inhibitive Effect of Tobacco Leaves Extract on Corrosion of Alpha Brass in Acidic Solutions

Ali Hubi Haleem

journal of kerbala university, 2008, Volume 4, Issue 3, Pages 80-91

This study was a trial to find an organic inhibitor that can to easily be prepared and applied , as well as non- toxic , cheep and available. In the present study an aqueous extract of tobacco leaves as corrosion inhibitor to protect α brass alloy in acid solutions (hydrochloric and nitric acid) at 1 M concentration, the inhibitor efficiency was evaluated using the weight loss method and microscopic test. Results obtained reveal that the extract of tobacco leaves plants at various concentration (0.5, 1.5, and 3) vol. % show significant corrosion inhibition during immersion of brass in acid solutions. The inhibition efficiency increased with increasing concentration of the inhibitor, but decrease with increase in exposure time. Inhibitor efficiency in 1M HCl and 1M HNO3 at ( 3%) concentration of inhibitor reached to 75.64% and 73.17% respectively. Microscopic examination test shows the clearness of the metals surface which is under the corrosion medium and which contains inhibitor, from any kind of corrosion that can be found on those surfaces, which are under mediums completely empty from inhibitor, and also shows the clearness of that protect layer on the surface. The data of corrosion rate show that the way of doing this organic inhibitor is adsorbing and the inhibitor molecules are adsorbed on the metal surface according to Langmuir adsorption isotherm.

Active Inhibitor as Corrosion Protective of Carbon Steel

Ali Hubi Haleem

journal of kerbala university, 2007, Volume 3, Issue 3, Pages 196-207

The present study is attempted to find new inhibitors that can to easily be prepared and applied, as well as nontoxic, cheap and available. In this study hibiscus leaves extractor was used to protect carbon steel in hydrochloric acid solution (1M, 2M, and 3M). Since the usable inhibitor is considered organic inhibitor, and for evaluating the inhibition performance of this compound, many tests have been conducted which include measuring the corrosion rate through methods known weight loss and microscopic examination test. In losing weight method the inhibitor gives good efficiency in protecting, the carbon steel to be corroded at 1M HCl is 77% while the efficiency is drop to 68% in 3 M HCl at 30 oC. Microscopic examination test shows the clearness of the metals surface which is under the corrosion medium and which contains inhibitor, from any kind of corrosion that can be found on those surface, which are under mediums completely empty from inhibitor, and also shows the clearness of that protect layer on the surface. The data of corrosion rate show that the way of doing this organic inhibitor is adsorbing and the inhibitor molecules are adsorbed on the metal surface according to Langmuir adsorption isotherm.