On the Influence of Yttrium and Sulphur on the High Temperature Oxidation Behaviour of Alumina-Forming High Purity FeCrAl Alloys

Many hypotheses have been published in the literature to explain the beneficial effect of reactive elements on the oxidation behaviour of alloys. Although this effect has been known for more than 50 years, the mechanisms involved are not yet very well understood. In order to minimize the influence of impurities in the alloys, in our approach pure metals are used to produce alloys which guarantee well defined starting conditions for two-stage-oxidation experiments. SNMS was chosen to investigate transport phenomena and the growth mechanisms of oxide scale. Sulphur and yttrium yield significant differences in oxide scale composition and microstructure during oxidation at 1200°C