Evaluation of the corrosion inhibitive behaviour of pawpaw fluid on a315 mild steel and a304 stainless steel in h2so4 medium

Abstract

In this research work, the evaluation of the corrosion inhibitive performance of pawpaw fluid on A315 mild and 304 stainless steels in 0.5M H2SO4 (through weight loss approach) was investigated. The investigation involved the effects of variation in the inhibitor concentrations (0 – 10 %vol/vol) on weight loss, corrosion rate, inhibitor efficiency and the morphological structure of the metal samples. The weight-loss method involved the subjection of metal samples to the corrosion process in the acidic medium for 21 days. The results of both weight loss and corrosion rates revealed that pawpaw fluid inhibitor with a concentration of 10 %vol/vol gave the highest inhibitor efficiency of 89.9% and 87.1% for A315 mild and A304 stainless steels respectively. Also, results obtained showed that Langmuir adsorption isotherm accurately described the behavior of the adsorption mechanism and the physical adsorption (spontaneous) nature of the inhibitor was justified by the negative values of ∆Gads. Chemical composition results and the SEM analysis revealed that stainless steel has better corrosion resistance performance in 0.5M H2SO4 medium compared to mild steel (under the same experimental condition).