Abstract
The growth rate and adhesion of the protective alumina scales on the heat resistant FeCrAl alloys are known to depend on minor metallurgical additions of the “reactive elements” such as Y, Ti, Zr, etc. The present study of high purity model FeCrAl alloys illustrates that the oxidation behaviour of these materials is strongly affected by trace amounts (up to 300 mass ppm) of carbon and/or nitrogen impurities. During long term high temperature oxidation testing of high purity model alloys it has been found that the carbon and nitrogen can interact with the reactive elements, such as Zr and Ti in the ferritic alloy matrix, resulting in a number of important effects on the scale growth and adherence. These effects can be beneficial as well as detrimental, depending on the exact amount and/or distribution of the mentioned minor alloying elements and C/N-impurities.
