V3I5P121

Corrosion Inhibition of C-1026 Steel Using Carica Papaya in Hydrochloric Acid

Newton I. Agbeboh^1*  Kokoro A. Abraham²

Abstract

The corrosion inhibition behaviour of Carica papaya leaf extract (CLE) on C-1026 mild steel in 0.5 M hydrochloric acid (HCl) solution was investigated using weight loss measurements at temperatures ranging from 303 K to 333 K. The inhibitor concentrations were varied from 1 g/L to 5 g/L. Corrosion rate, inhibition efficiency, and surface coverage were calculated from weight loss data from the study. The results demonstrated that CLE effectively inhibited corrosion of C-1026 steel in HCl at all concentrations studied, with maximum inhibition efficiency of 100% recorded at 5 g/L and 313–323 K. The corrosion rate decreased with increasing inhibitor concentration but increased with rising temperature, suggesting a physisorption adsorption mechanism. The Temkin adsorption isotherm provided the best fit for the experimental data, with R² values close to unity across all temperatures. Activation energy and heat of adsorption values further corroborated the inhibition mechanism. These findings confirm CLE as a promising, eco-friendly, and cost-effective green corrosion inhibitor for mild steel in acidic media.

Keywords:

Carica papaya; corrosion inhibition; C-1026 steel; hydrochloric acid; weight loss; Temkin isotherm; green inhibitor