Inhibition of Stainless Steel Corrosion in 0.5 M H2SO4 in the Presence of C6H5NH2

Inhibition of stainless steel corrosion in 0.5 M H₂SO₄ by C₆H₅NH₂ (Aniline) at different temperatures was experimentally studied in this paper. Corrosion rate measurements at 28°C, 45°C and 60°C were taken through linear sweep voltametry and utilised for modelling inhibition efficiency and thermodynamic properties in the acidic solution containing different concentrations of the organic chemical. Results showed that inhibition of stainless steel in 0.5 M H₂SO₄ increased with increasing temperature for most of the different concentrations of C₆H₅NH₂ employed. Optimal inhibition efficiency ranged from η = 26.49% by 0.043 M C₆H₅NH₂ at 28°C, through η = 88.99% by 0.021 M C₆H₅NH₂ at 45°C up to η = 96.68% by 0.043 M C₆H₅NH₂ at 60°C. Also, thermodynamic property analyses showed that apparent activating energy decreases from the uninhibited, 0 M C₆H₅NH₂, to the optimally inhibiting 0.043 M C₆H₅NH₂ containing medium, which suggests C₆H₅NH₂ adsorption drives the inhibition effects observed.