Effect of dispersoids on tensile deformation of Fe-20Cr ODS alloys

Tensile deformation properties of nine kinds of mechanically alloyed Fe-20Cr-based oxide dispersion strengthened (ODS) steels were examined over a temperature range from 300 to 1073 K. One of the specimens used was an alloy without any addition of oxide and the others were eight kinds of ODS alloys with the addition of Y2O3, Al2O3, SiO or ZrO2. All of the alloys had fine grain structures. With the addition of Y2O3 the 0.2% yield stress of Fe-20Cr alloys increased all over the temperature range, and the work-hardening following the yield at 300 and 673 K also increased considerably. But at higher temperatures than 673 K, the increment of work hardening due to the oxide dispersion was small. Fracture elongation at 673 K was found to be about 5%, while those at 873 and 1073 K were more than 17%. The dispersion strengthening due to the other oxides, Al2O3, SiO and ZrO2 were very small except that of ZrO 2 at 1073 K.