Synthesis of Fe-15Cr-2W oxide dispersion strengthened (ODS) steel powders by mechanical alloying

Ferritic steels strengthened with uniformly dispersed oxides (ODS steel) have potential applications as a fuel cladding material in future nuclear reactors. In the present investigation, ODS steel with a nominal composition of Fe-15Cr-2W-0.3Y2O3 was synthesized from elemental powders by mechanical alloying in a high-energy Simoloyer attritor ball mill. The structural evolution occurring in the course of mechanical alloying at interrupted milling durations was investigated by XRD, SEM, TEM, and DTA. Dissolution of Cr took place at an earlier stage as compared to that of W and a complete solid solution was found to occur at 10 h of milling. Yttria was found to be stable (undissolved) and consistent till 10 h of milling though its size was refined. A strong influence of the dissolution of W in shrinking the austenite region and corresponding changes in the transformation temperatures was observed in the DTA analysis.