Figure 4

Potentiodynamic polarization graphs for API X120 steel at 0.167 mV S⁻¹ scan rate in carbonated 3.5 wt% NaCl solution in the presence and the absence of 25, 50, 75 and 100 mol L⁻¹ of PEI at different temperatures where (A) 20, (B) 30, (C) 50 and (D) 70 °C.