Inhibitive Action of Hydroxylammonium Sulfate on the Corrosion of Carbon Steel in Hydrochloric Acid Medieum and their Adsorption Characteristics

Abstract

The inhibitive action of Hydroxylammonium sulfate ((NH 3 OH) 2 SO 4 ) (HAS) on corrosion of carbon steel (CS) in 1M HCl was studied by weight loss, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and effect of temperature. The measurements show that inhibition efficiencies increase with the increasing of HAS concentrations but decrease with increasing temperatures. This reveals that inhibitive action of the inhibitor was mainly due to adsorption on the carbon steel surface and blocking of the active sites. The above results showed that HAS acted as a mixed-type corrosion inhibitor. The adsorption of HAS on the carbon steel surface obeyed the Langmuir adsorption isotherm. This was supported by the impedance measurements which showed a change in the charge transfer resistance and double layer capacitance, indicating the adsorption of HAS on the carbon steel surface. Thermodynamic parameters of the studied inhibitor were calculated and discused.