In this paper, the effect of grain refinement on the electrochemical behavior of AISI 430 ferritic stain-less steel in 0.1 M NaOH solution was investigated. Potentiodynamic polarization curves showed thatfine-grained samples have less corrosion potential, higher corrosion current density, and less protec-tive passive film in comparison to coarse-grained samples. Electrochemical impedance spectroscopy(EIS) analysis revealed that implementing the thermomechanical operation led to lower polarizationresistance. Also, Mott–Schottky analysis revealed that the passive films on both fine-grained and coarse-grained samples behave as n-type and p-type semiconductors and the semiconductor character of thepassive films did not change by grain refinement. Moreover, it was found that the calculated donorand acceptor densities increased with grain refinement. Thus, the presented results indicated that grainrefinement weakens the corrosion and passivation behavior of AISI 430 stainless steel in this alkalinesolution.
