Corrosion resistance of anodic layers grown on 304L stainless steel at different anodizing times and stirring speeds

Different chemical and physical treatments have been used to improve the properties and functionalities of steels. The anodizing is one of the most promising treatments, due to its versatility and easy industrial implementation, since it allows obtaining different microstructures on the surface, in order to be employed in different industrial sectors. The present work has studied the influence of the anodizing time (15, 30, 45 and 60 min), as well as the stirring speed (0, 200, 400 and 600 rpm), on the morphology and the resistance corrosion behavior of anodic layers grown in 304L stainless steel. The anodic layers were characterized morphologically, compositionally and electrochemically, in order to determine the influence of these parameters on their corrosion behavior in a 0.6 M NaCl saline solution. The results show that the generation of anodic layers at different times propitiates the definition of nonporous morphologies, while the phenomena of dissolution of the layers that increase with the time of anodizing. However, the resistance to corrosion decreases respect to the non-anodized 304L SS. On the other hand, the effect of the stirring speed during the generation of these anodic layers does not seem to influence the corrosion behavior in the saline medium studied.