It was recalled that TWIP steels were characterized by high work-hardening rates, due to continuous mechanical twin formation during deformation. Mechanical twinning was a unique deformation mode which was closely controlled by the stacking-fault energy. A steel containing 18Mn-0.6C-1wt%Al had a stacking-fault energy of about 25 to 30mJ/m2 at room temperature. This stacking-fault energy ensured that mechanical twinning was the main deformation mechanism at room temperature. The Correlation between Stacking Fault Energy and the Work Hardening Behaviour of High-Mn Twinning Induced Plasticity Steel Tested at Various Temperatures. V.Shterner, I.B.Timokhina, H.Beladi: Advanced Materials Research, 2014, 922, 676-81