ABSTRACT
Five different parts of Acacia nilotcaplant (leaves,pods,seed,bark and root) were subjected to the following analyses; extraction, phytochemical screening, corrosion inhibition test of low carbon steel in crude oil using gravimetric analyses, mechanical properties and surface morphology evaluation of the samples.The corrosion rate of low carbon steel specimen in the plant extract was found to decrease with immersion time(120hrs-792hrs) and with increase in concentration of the inhibitor(400ppm-1000ppm). The results further showed a decrease in inhibition efficiency (IE) of the inhibitor at elevated temperatures(40�C,50�C,60�C) indicating a physisorption of extracts on the carbon steel surface.The result from the mechanical properties(tensile,hardness and impact) evaluation showed higher values(741MN/m2,98.2HRBand 11.52J)for the inhibited samples than the uninhibited(692MN/m2,92.6HRB,11.11J) The values of activation energy, free energy of adsorption and heat of adsorption of all the inhibitors were calculated in order to investigate the mechanism of corrosion inhibition.Adsorption on low carbon steel was found to obey the langmuir adsorption isotherm.All the parts of the plant showed good inhibition efficiency in the medium ranging from56.64%to 98.78% but the pod was the best with inhibitor efficiency of 98.78%.