Investigation of adenine inhibitor on corrosion behavior of AISI 304 and 316 stainless steel in 1 N HCl solution

The inhabitation behavior of adenine for 304 and 316 stainless steels (SS) in 1 N hydrochloric acid solution at ambient temperature was studied using weight loss, electrochemical methods and surface characterization. Result showed the corrosion rate of stainless steel significantly is reduced by addition of 70 mg/L adenine with maximum inhibitation efficiency of 83 and 65 percent for 304 and 316 SS, respectively. The potentiodynamic investigation demonstrated the studied inhibitor acting as a mix type inhibitor with the predominant of anodic inhibitation. EIS studies indicated a main increase in polarization resistance after adenine addition. The surface morphology and EDS analysis of specimens after exposure to acidic solution with and without inhibitor exhibited the material surface are protected by formation of protective film layer. Adsorption of adenine inhibitor on 304 and 316 SS was found in accordance with Langmuir adsorption isotherm, and isotherm parameters including Kads and ΔGads0 were determined in ambient temperature.