In this research, cathodic arc evaporation and magnetron sputtering as two instances of PVD methods were used for deposition of a thin film of stainless steel on a carbon steel substrate. Structure and grain size of the coatings were evaluated by SEM and FE-SEM methods. Composition of the coatings was assessed by EDS analysis. Also, corrosion tests such as potentiodynamic and potentiostatic polarization, cyclic polarization, electrochemical impedance spectroscopy and mott-schottky analysis were performed in 3.5 wt. % NaCl and 2 M sulphuric acid solutions as corrosive environments. In addition, for investigation of mechanical behavior of the coatings, used from Vickers indenter for evolving the coatings adhesion and calculating their fracture toughness. Also, nano-indention tests were used for measuring hardness, elastic modules and impactability of the coatings. In the nano-indention test observed that the magnetron sputtered coating had 889 Vickers hardness that is much higher than bulk 304 stainless steel with 220 Vickers hardness. In addition, EDS analysis showed that the magnetron sputtered coating composition was close to the target material. Although, because of the evaporation condition in the cathodic arc evaporation method, a composition difference between target and coating and coating matrix and growth defects was detected. The growth defects were effective at the corrosion behavior of the coating. Potentiostatic and mott-schottky results showed that decreasing chromium during deposition in cathodic arc system resulted to the formation of a weak oxide layer for the coating. So that in NaCl solution because of the presence of Cl - ions, the formation of a passive layer was only possible on needle-like growth defects with high chromium and nickel content and in sulphuric acid solution extent of the passive region was decreased than bulk 304 stainless steel. Keywords: stainless steel coating; cathodic arc evaporation, sputtering; corrosion
