Fabrication and characterization of aluminum-containing ferritic ODS alloys for improved corrosion resistance

Future generation nuclear reactors will have demanding requirements on materials. Present materials are unable to cope with the desired operating temperatures and environments. Ferritic ODS alloys are candidate materials which might meet these requirements. Especially, alloys with additional aluminum content have a large potential to withstand the corrosive environments. In the present study, 12-14%Cr ferritic ODS alloys with varying aluminium content produced by mechanical alloying are investigated. After mechanical alloying of a pre-alloyed steel powder with aluminum in an attritor ball mill, the process was investigated by SEM and TEM analysis of the milled powder particles. After compacting by hot isostatic pressing and hot-rolling followed by annealing, the mechanical properties of the materials were assessed by tensile tests and hardness measurements. The results showed that the aluminum content has a big influence on the powder particle size during mechanical alloying. Also a drop in the yield strength could be observed. All further results are analyzed, compared, and discussed in this paper. (author)