Protection of 304 Stainless Steel with TiO2 Coating
Tooru Imokawa, Ryutaro Fujisawa, Arata Suda, Shigeo Tsujikawa
The photoelectrochemical behavior of 304 stainless steel coated with TiO2 by sputtering was studied in NaCl solutions at ambient temperature. It was confirmed that the coating from 30 to 100nm thick could protect 304 stainless steel cathodically under illumination. The coating defects don't hinder the protection performance when its area ratio is less than 1/10. As shown by Honda and Fujishima, the anodic reaction on TiO2 is neither dissolution nor photodecomposition but oxygen evolution. Therefore, the TiO2 coating is expected to work as a non-sacrificed anode. This is a highly contrasted feature of the coating as compared with zinc coating for steels which is destined to be consumed.