The influence of Cr and Ce additions on the mechanical properties of Fe3Al based alloys

The influence of Cr and Ce solutes on the hardness evolution of an Fe–28 at.% Al alloy during isothermal and isochronal annealing in the temperature range 300–1000°C was studied. In the Cr-containing alloys, Cr–Fe–(C) precipitates were found after hot working and cooling. These precipitates were dissolved during annealing at 1000°C for 2 h. Subsequent isothermal and isochronal annealing caused their reprecipitation starting above 300°C. Preferentially they nucleate on dislocations, nearest-neighbor antiphase boundaries and subgrain and grain boundaries. It appears that the precipitate formation decreases the hardness of the alloy. The Ce addition and the Ce-containing particles influence neither the formation of Cr–Fe–(C) precipitates nor the evolution of hardness of the alloy.