Influence of cerium implantation on the nucleation and growth of corrosion products on Alloy 800H in a mixed sulphidizing/oxidizing environment
The influence of implantation of cerium on the corrosion behaviour of a 32Ni-20Cr austenitic steel, Alloy 800H, in a simulated coal-gasification atmosphere has been examined at 700 C. The composition and microstructure of the corrosion products formed after exposure periods between 1 min. and 200 h were examined using a range of surface-analytical techniques. The corrosion mechanism of Alloy 800H was characterised as a mixture of oxidation and sulphidation, primarily of Cr and Fe. The oxides provided protection against catastrophic sulphidation. Cerium implantation reduced the corrosive attack, providing the dose was sufficient. The corrosion was more uniform and the products had a higher Cr/Fe ratio compared to those on the unimplanted alloy. It is suggested that these changes resulted from the formation of a more protective and more stable oxide layer, due to the rapid formation of ceria particles, specifically hindering the formation of the less-stable oxides and sulphides.
Bibliographic Reference: Article: Oxidation of Metals, Vol. 35 (1991) Nos 1/2, pp. 19-33
Record Number: 199110785 / Last updated on: 1994-12-02
Original language: en
Available languages: en