Gas atomization reaction synthesis was used to surface oxidize ferritic stainless steel powders (I.e., Fe-16.0Cr-(0.1-0.2)Y-(0.1-0.5)(Ti or Hf) at.%) during the primary break-up and solidification of the moltenalloy. This rapid surface reaction resulted in envelopment of the powders by an ultra thin (I.e., t <100nm) metastable Cr-enriched oxide shell. This metastable oxide phase was subsequently dissociated,and used as an oxygen reservoir for the formation of more thermodynamically favored Y-(Ti,Hf) nanometricoxide precipitates during elevated temperature heat treatment of the as-consolidated powders. Thisoxygen exchange reaction promoted the formation of nano-metric oxide dispersoids throughout the alloymicrostructure. The atomization processing parameters were adjusted to tailor the oxygen content in asatomizedpowders. Microstructure phase analysis was completed using transmission electron microscopyand X-ray powder diffraction.
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