Effects of Nb and C additions on the microstructure and tensile properties of lightweight ferritic Fe–8Al–5Mn alloy

Additions of Nb and C result in the formation of NbC and κ-carbide in Fe–8Al–5Mn alloy. Both NbC and κ-carbide particles inhibit recrystallization during hot rolling with the resultant formation of pancake-shaped grain structure in Fe–8Al–5Mn–0.1Nb–0.1C alloy, but κ-carbide particles also promote recrystallization via particle-stimulated nucleation mechanism during subsequent warm/cold rolling and annealing. As a result, Fe–8Al–5Mn–0.1Nb–0.1C alloy has a much finer grain size and a better combination of tensile properties than Fe–8Al–5Mn alloy.