Deformation twinning, martensitic phase transformations and mechanical properties of austenitic Fe-(15-30)wt%Mn steels with additions of aluminium and silicon were investigated. Additions of aluminium increased the stacking-fault energy and thus strongly suppressed the γ → ε transformation. Silicon additions decreased the stacking-fault energy and sustained the γ → ε transformation. The γ → ε phase transformation took place in steels with a stacking-fault energy of up to 20mJ/m2. For steels with a higher stacking-fault energy, twinning was the main deformation mechanism.

High Strength Fe-Mn-(Al,Si) TRIP/TWIP Steels Development - Properties – Application. O.Grässel, L.Krüger, G.Frommeyer, L.W.Meyer: International Journal of Plasticity, 2000, 16[10], 1391-409