Surface study of the blue colored 430 stainless steel by electrochemical method

The characterization of architectural coatings grown on the surface of AISI 430 stainless steel by an electrochemical coloration process was realized by multiple techniques. The interference colored coatings was grown in a sulphochromic solution at room temperature by an alternating pulse current method. Color tones were achieved by appropriate control of current cycles and the cathodic potential. The grain boundaries of the blue colored film were less susceptible to etching for the current pulse method as compared to other conventional approaches. Surface study of the blue color film was investigated by field atomic force microscopy (AFM), depth-sensing indentation (DSI) experiments and was employed to assess the mechanical resistance of the film. The coloration process resulted in porous thin films which increased the surface roughness of the substrate. The interference films mainly consisted of hydrated chromium oxide containing iron.