Aluminum partitioning during phase separation in Fe-20%Cr-6%Al

Abstract

Phase separation in a commercial Fe–20 wt.% Cr–6%Al oxide dispersion-strengthened PM 2000 steel has been characterized with a local-electrode atom probe after isothermal aging at 708 Kand 748 Kfor times up to 3,600 h. A progressing decrease in the Al content of the Cr-rich a0 phase was observed with time at both aging temperatures. The Al partitioning trend was consistent with theoretical calculations. However, the experimentally observed Al partitioning factor was significantly lower than the predicted equilibrium value. A *10 nm diameter, roughly spherical, Al- and Ti-enriched b0 Fe(AlTi) phase was also observed