LAUSR

Abstract The corrosion behavior of steel in 0.5 M H2SO4 solution in the presence of polyethylene glycol (PEG 6000) as a green corrosion inhibitor was investigated under well-defined hydrodynamic conditions simulated by a steel rotating disk electrode with the rotation speeds of 250–5000 rpm. The results obtained from electrochemical impedance spectroscopy and potentiodynamic polarization measurements demonstrated the better protection of steel at higher concentrations of the polymer. Additionally, the corrosion inhibition experienced a dramatic reduction in going from hydrostatic to hydrodynamic conditions. This was indicated by corrosion resistance (Rcorr), which reduced from 162 Ω cm2 at the stagnant condition to 65.7 Ω cm2 at the dynamic state with a flow rate of just 250 rpm in the presence of 5 g L−1 PEG. This observation was a consequence of the transportation of corrosion products from the metal surface toward the bulk in fluid flow conditions, leading to a restriction in the formation of an adhesive protection layer on the steel surface.