Corrosion can be influenced by either the nature of the metal, nature of the environment (temperature, aeration, agitation or pH of the electrolyte) or the corrosion products. In order to minimize or completely eradicate they effects as a result of these influences on corrosion of 2205 duplex stainless steel, the corrosion inhibition performance of expired myambutol was studied in 0.5 M HCl environment at ambient temperature and elevated temperatures of 303, 313 and 333 K. The experimental and analysis work was carried out using both chemical and electrochemical techniques. Analytical results indicated that expired myambutol drug used as inhibitor adsorbed effectively on the surface of the 2205 duplex stainless steel hence inhibiting the factors influencing the corrosion of the steel. This was evident from the results of gravimetric, thermometric, EIS and Potentiodynamic polarization analysis recorded as 98.3 %, 98.5 %, 84.2 % and 91.9 % respectively. Generally inhibition efficiency increased with increased in concentration of expired myambutol inhibitor but decreased with rise in temperature, an indication of initial strong adsorption of inhibitor and a subsequent dissolution of inhibitor from metal surface as a result of strong agitation from prolong temperature effects. The physical adsorption process was attributed to the adsorption of inhibitor following the correlation coeffient values from the Langmuir profile drawn.

Keywords : Myambutol, Adsorption, Corrosion, Electrochemical, Polarization, Duplex Stainless Steel, Inhibition Efficiency, Enthalpy.