Effect of grain refinement on electrochemical behavior of Fe-18.5%Cr ferritic stainless steel in 0.1 M HNO3 solution

In the present study, the electrochemical behaviors of coarse-grained and fine-grained ferritic stainless steel in 0.1 M HNO3 solution were investigated using a series of electrochemical analyses. The potentiodynamic polarization curves for these two types of microstructures showed similar trends. It was also observed that grain refinement decreases the corrosion current density and increases the corrosion potential. Electrochemical impedance spectroscopy (EIS) analysis revealed that grain refinement increases the polarization resistance of ferritic stainless steel. Finally, it was concluded that the corrosion and passivation behavior of the investigated ferritic stainless steel in the 0.1 M HNO3 solution is improved by refining the grain structure.