Mechanical Alloying and Properties of ODS Ferritic Steels

Abstract

Oxide-dispersion strengthened (ODS) ferritic stainless steels have been considered as promising high-temperature materials such as interconnects for oxide-fuel cells and nuclear materials for Liquid Metal Fast Reactors or Super-Critical-Water-Cooled Reactors. In the present work, we have prepared Fe-14Cr-2Al-1Si-0.3Ta-1Y2O3 ferritic stainless steels which were dispersion-strengthened by nano-sized Y2O3 via mechanical alloying of elemental powder mixtures and subsequent hot consolidation. A comparison was made with MA 957 and DY-01 alloys. The mechanically alloying behaviour and consolidated mechanical properties of the Fe-14Cr-2Al-1Si- 0.3Ta-1Y2O3 ferritic steels were strongly influenced by processing parameters, especially milling atmosphere. The stability of yttrium oxides and oxidation resistance at high temperatures were examined. The preliminary result shows that the mechanically alloyed Fe-14Cr-2Al-1Si-0.3Ta- 1Y2O3 ferritic stainless steel exhibits interesting properties to be exploited as high temperature materials.