Evaluation of Corrosion Behavior of AISI 430 Ferritic Steel Coated With Aluminum, Titanium and Aluminum - Titanium by Pack Cementation Method in NaCl 3.5%

In this research, the electrochemical behavior of AISI 430 ferritic stainless steel at presence of Al, Ti and simultaneous co-deposition of Al-Ti diffusional coatings were studied in the simulated marine environment (NaCl 3.5%). To determine the microstructure and phases of the coatings, scanning electron microscopy (SEM) and X-ray diffraction (XRD) was used. To evaluate the corrosion resistance of coatings, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) methods were used. Electrochemical polarization results showed that co-deposition of Al-Ti coating has better corrosion resistance (4.55×10-4 μA.cm-2) in comparison to Al (3.21×10-2 μA.cm-2) and Ti (3.6×10-2 μA.cm-2) coatings. Also the results of electrochemical impedance showed that co-deposition of Al and Ti have higher charge transfer resistance of electric double-layer in comparison with Al and Ti coatings.