a b s t r a c t Nanostructured TiO 2 thin films were deposited on AISI 304 austenitic stainless steel by sol-gel process, dip coating technique. Influence of the number of layers, addition of polyethylene glycol (PEG) in initial sol, morphology and the surface roughness parameters of titania films on corrosion resistance of coated stainless steel were examined. Prepared films were characterized by SEM-EDS and AFM analysis. Electrochemical corrosion behavior of the coated stainless steel substrates was evaluated in simulated marine environment in 3 wt.% aqueous NaCl solution by electrochemical impedance spectroscopy (EIS) and in 0.5 M aqueous HCl solution by potentiodynamic polarization.

One‐layer, two‐layer and three‐layer titania films on AISI 304 stainless steel were deposited by sol‐gel process and dip‐coating method. Two sols were prepared by using titanium isopropoxide as a precursor, propanol as a solvent, nitric acid as a catalyst and acetylacetone for peptization. Both of the prepared sols contained the same amount of mentioned components, the only difference was in the addition of polyethylene glycol (PEG) as templating reagent to one of the sols. After calcination at 550°C, deposited films on the stainless steel substrate were characterized by atomic force microscope (AFM). Influence of layer number as well as addition of polyethylene glycol on morphology of titania films was analysed and discussed. Generally, by increasing the number of layers and by addition of polyethylene glycol, roughness parameters increase by changing surface topography. The surface topography analysis is very important when choosing the adequate industrial application of prepared layers.