An-Najah Staff

The inhibitive action of Hydroxylammonium sulfate ((NH3OH)2SO4) (HAS) on corrosion inhibition 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 increases with increasing of HAS concentrations but decreases with increasing temperatures. This reveals that inhibitive action of inhibitor was mainly due to adsorption on the carbon steel surface and blocked 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 adsorption of HAS on the carbon steel surface. Thermodynamic parameters of studied inhibitor were calculated and discused.

The effect of adding 2-phenylimidazo[1,2-a]pyridine-3-carbaldehyde derivative named (P2), newly synthesized on the electrochemical behavior of C38 steel in molar hydrochloric acid was investigated by using the weight-loss method, potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS) measurements. EIS results show that the transfer resistance increases with the increase of concentration of P2 and it also had an inhibiting effect on C38 steel corrosion in HCl solutions. Weight-loss essays confirm that the corrosion rate decreases as the P2 concentration increases. The inhibition efficiency for this compound studied increased with the increase in the inhibitor concentrations to attain 91.7 % at the 10−3 M of P2. The potentiodynamic polarization curves indicated that P2 acted as a mixed-type inhibitor in hydrochloric acid.