Alumina films have been successfully formed on austenitic stainless steels containing 4 and 5 wt % Al by selective oxidation of Al in a H2O/H2 environment. γ-alumina films have been formed by oxidation at 800°C and δ-alumina films at 900°C. Satisfactory corrosion resistance performance for ozone gas has been obtained for both γ- and δ-alumina films. For ozonized water, δ-alumina films formed with pH2O/pH2≤1 × 10-4 have good corrosion resistance while δ-alumina films formed with pH2O/pH2≥3 × 10-4 or γ-alumina films do not. Holes of a characteristic triangular shape are observed on the oxidized surface of stainless steels containing 4 wt % Al, probably caused by the habitual formation of precipitated β-(Fe,Ni)Al. No such hole has been observed on the oxidized surface of stainless steels containing 5 wt % Al.
|Number of pages||7|
|Journal||Journal of Vacuum Science and Technology A: Vacuum, Surfaces and Films|
|Publication status||Published - 1999|
ASJC Scopus subject areas
- Condensed Matter Physics
- Surfaces and Interfaces
- Surfaces, Coatings and Films