ELABORATION AND STUDY OF MECHANICALLY ALLOYED ODS FERRITIC STAINLESS-STEEL

O.D.S. ferritic stainless steel has been elaborated by mechanical allo ying from elemental powders and fully characterized by SEM, TEM, EDS a nd XRD. Macroscopic and microstructural evolutions of the material hav e been determined as a function of milling time. It has been observed that the changes in composition and structure are dramatic up to 40 mi lling hours. For higher milling durations, the powder characteristics are nearly unchanged. Two kinds of reinforcing dispersoids have been i dentified by TEM on HIP compacted powders: titanium compounds (50-200 nm) in the grain boundaries and complex yttrium oxide nanometer sized particles inside the grains.