Proceedings of the 3rd International Symposium on High Temperature Corrosion and Protection of Materials
Actes du 3ème Colloque International sur la Corrosion et la Protection des Matériaux à Haute Température

J. Phys. IV France 03 (1993) C9-291-C9-299
DOI: 10.1051/jp4:1993928

Influence of yttrium on high temperature behaviour of Fe-Cr-Al-Y alloys

F. Clémendot, J.M. Gras and J.C. van Duysen

Département Etude des Matériaux, Direction des Etudes et Recherches, Electricité de France, Les Renardières, B.P. n° 1, 77250 Moret/Loing, France

Abstract
We have studied the oxidation behaviour of three industrial Fe-Cr-Al alloys (with or without yttrium) at temperatures ranging between 1200 and 1350 °C. At 1200 °C, the behaviour of these alloys is improved as the yttrium content rises. However, for temperatures higher or equal to 1300 °C , the presence of yttrium seems to be detrimental. In particular, the distribution of this element in YFe₉ or Y₂Fe₁₇ intermetallic particles allows yttrium to diffuse towards the surface of the product. The high kinetic of this diffusion leads to the formation of oxidized cavities by Kirkendall effect. The results obtained on the 0.14%-yttrium product show that the distribution of this element under the oxidized form could help to avoid this damage.

© EDP Sciences 1993