Inhibition effect of Phenylamine on the Corrosion of Austenitic Stainless Steel (Type 304) in dilute sulphuric acid

摘要

The corrosion of austenitic stainless steel (type 304) in dilute sulphuric acid solutions in addition to recrystalized sodium chloride concentrates in the presence of specific proportions of phenylamine was studied with the aid of polarization resistance technique, electrode potential monitoring and coupon method. Results showed the overwhelming influence of the compound in corrosion inhibition with an inhibition efficiency of 97.5% from coupon analysis and 86.10% from polarization test at highest observed concentration of the inhibitor. Corrosion potential measurement showed potentials well with passivation values. Corrosion rate decreased progressively with increase in concentration of phenylamine. Adsorption of the compound on the steel surface followed the Langmuir isotherm model. Thermodynamic calculations showed the interaction mode with the steel to be physiochemical. Observation from scanning electron microscopy and x-ray diffractometry showed the electrochemical impact on the surface topography and the phase compounds of the steel samples studied. Results from statistical analysis depict the sharp influence of inhibitor concentration on the electrochemical performance of the compound.