Corrosion protection of mild steel by organic inhibitors

Mild steel is a very important industrial metal and it uses in several operational units. Bulk amount of sulphuric acid is used with phosphate raw materials during
production phosphate fertilizer. Mild steel is a sensitive metal in acidic medium. It starts
corrosion reaction with metal. It changes their physical, chemical and mechanical
properties, tarnishes their facial appearance and its deterioration occurs due to corrosion
reaction. Metal is suffering from various types of corrosion like galvanic corrosion,
pitting corrosion, crevice corrosion, stress corrosion and other types of corrosion.
Organic inhibitors 2-(aminomethyl) phenol and 2-(aminomethyl) aniline are used as
corrosion resistance for this work. These inhibitors anticorrosive properties studied at
different temperatures 600C, 700C and 800C and 5mM their concentration. The corrosion
rate of metal was calculated by gravimetric technique. Corrosion current density was
determined potentiostatic polarization techniques. Inhibitors' surface adsorption
phenomenon, thermal stability, physisorption-chemisorption activities, surface films
formation were studied by application of activation energy, heat of adsorption, free
energy, enthalpy and entropy. Inhibitors occupied space on interface i.e. confirmed by
surface coverage area and inhibition efficiency. Potentiostat results were shown that
these inhibitors developed polarization on the surface of base metal.