The inhibition of the corrosion of Armco iron in hydrochloric acid solutions by organic surfactants

The polarization behaviour of Armco iron in solutions of HCl with and without inhibitors has been studied by potentiostatic method. At lower overvoltage values the dissolution process is controlled by activation, while at higher overvoltage values the dissolution process is controlled by diffusion. The inhibition of this metal corrosion in the aqueous solutions of HCl has been studied using three surfactants. Under the critical micelle concentration the inhibition of those three surfactants is negligible. At a concentration higher than critical micelle concentration, the inhibiting action of surfactants increases rapidly. The process of inhibition was attributed to the formation of the adsorbed film on the metal surface, that protects the metal against the corrosive agents.