Long Term Oxidation of Fecral ODS Alloys at High Temperature

Autor: Régine Molins, L. Menneron, I. Alliat, G. Merceron, Jean Loup Strudel
Rok vydání: 2001
Předmět:
Zdroj: Materials Science Forum. :269-276
ISSN: 1662-9752
DOI: 10.4028/www.scientific.net/msf.369-372.269
Popis: The oxidation resistance of a commercial oxide dispersion strengthened alloy (MA 956) was examined after long exposures at high temperature. Isothermal and cyclic oxidation treatments were carried out in laboratory air at 1200°C and 1300°C for a few thousand hours in order to study the oxide scale stability (criteria of protection and spalling of the alumina film). Chemical analyses of the substrate for increasing treatment duration revealed a continuous decrease of the matrix aluminium content due to the oxide growth. As soon as the aluminium content fell below a critical value, the alloy could no longer develop a continuous and protective alumina layer. Aluminium nitrides were observed in the substrate beneath the oxidised surfaces, later associated with the iron rich oxide formation after the spallation of the alumina scale. A model to predict the service lifetime of industrial components was established, taking into account the critical parameters involved in the breakaway oxidation phenomenon.
Databáze: OpenAIRE