Electrochemical investigation on the corrosion and hydrogen evolution rate of mild steel in sulphuric acid solution

Corrosion and hydrogen evolution rate of mild steel alloy have been investigated using various electrochemical techniques. Mild steel was polarized vs. saturated calomel electrode (SCE) in naturally aerated 0.1 M H2SO4 solution containing three newly synthesized heterocyclic compounds in different concentrations. The data obtained from polarization technique showed that the corrosion current density, icorr, and the hydrogen evolution rate decrease with increasing concentration of heterocyclic inhibitors in 0.1 M H2SO4 medium, indicating a decrease in the corrosion rate of mild steel as well as an increase in the inhibition efficiency (IE) of the newly synthesized inhibitors. The impedance measurements confirmed well the polarization behaviour. Increasing the temperature leads to an increase in corrosion or hydrogen evolution rate of the mild steel and a decrease of the total resistance value (RT) or the relative thickness (1/CT) of the film. The obtained results were confirmed by surface examination using scanning electron microscope.

► EIS and Polarization measurements showed that corrosion rate of mild steel decrease with increasing inhibitor concentration in tested solution. ► Increasing the temperature leads to an increase in corrosion or hydrogen evolution rate of the mild steel. ► Obtained results were confirmed by surface examination using scanning electron microscope.