IRAQI ORANGE PEEL EXTRACT INHIBITS CORROSION OF METALLIC ALLOYS IN HYDROCHLORIC ACID SOLUTION

The main purpose of this work is to investigate the properties of Iraqi orange peel extract as an inhibitor of corrosion of metallic alloys (low carbon steel (SAE AISI 1018 steel), copper alloy (a-Brass) C27400 and aluminium alloy (EN AW-5083)) in 0.5 M hydrochloric acid medium. The mass loss test and electrochemical test were used to assess the extent of corrosion in the presence of orange peel extract, and various kinetic and thermodynamic parameters were calculated and discussed in order to understand the corrosion and inhibition mechanism. For all metallic alloys studied, the corrosion rate decreased as the concentration of orange peel extract increased. It was also found that the corrosion rate decreased in line with the length of exposure of the alloy to the orange peel extract. As a result of using the Iraqi orange peel extract with a concentration of 500 ppm in the 0.5 M HCl acid, it led to a reduction in the corrosion rate of low carbon steel from 12.37 to 5.34 mpy, while in case of a-Brass Alloy the corrosion rate decreased from 1.44 to 0.34 mpy, either in the case of using 5038 aluminium alloy, the corrosion rate decrease from 71.123 to19.678 mpy. These results suggest that the adsorption of orange peel extract on the surface of the metallic alloys leads to the formation of a protective layer that inhibits the action of the hydrochloric acid solution, and this layer develops in thickness and effectiveness as the immersion time increases.