ABSTRACT

 One of the major challenges facing the engineering industry is corrosion, it is an adversary worthy of all the high technology and research we can throw at it, therefore the need to study the corrosion behaviour of metals when exposed to various environments, as this is an important factor in material selection that determines the service life of the material. Corrosion, being a major problem in different industries has been a subject of concern in recent researches. This industrial challenge, when not properly managed results in great increase in the operating costs, hence a decrease in the net profit of industries. The following materials was used in this study includes Warring blender, beakers, filter paper(whatman number 42), Brush, Clock, Desiccator, Electronic Weighing Balancc(sensitive analytical balance), Corrosion study kit, Masking tape, the result showed that carbons steel corrodes in the corrosive environment since there was a progressive decrease in the original weight of the coupons. The results from this work have clearly shown that the ideal volume where Allium cepa extract exhibited maximum inhibitory reaction was 2m1 for the mild steel studied, which could possibly be used for industrial purposes. Corrosion rate is inversely proportional to the inhibitor concentration up to the critical concentration of 2m1 after which it becomes directly proportional. The efficiency of the inhibitor is inversely proportional to the inhibitor concentration. Predicted optimum inhibitor efficiency from regression model was 83.156% while that obtained from the experiment was 89.39%. I recommend that techniques such as Potentiadynamic polarization, Electrical Resistance measurement and linear polarization resistance technique should be used to validate these findings.Further research on how to improve on the extraction process should be carried out. The engineering industries should embrace natural corrosion inhibitors like allium cepa in combating corrosion.