The principal features of deformation twinning in faced-centered cubic austenitic steels were considered, and it was shown how a physically-based macroscopic model could be derived from microscopic-level considerations. In fact, a dislocation-based phenomenological model, with internal state variables including dislocation density and micro-twins volume fraction describing the microstructure evolution during deformation process, was proposed to model the deformation behavior of TWIP steels. The originality of this work lay in the incorporation of a physically based model on twin nucleation and volume fraction evolution in a conventional dislocation-based approach. Microstructural level experimental observations with scanning electron microscope and transmission electron microscopy techniques together with the macroscopic quasi-static tensile test, for the TWIP steel Fe–17.5Mn–1.4Al–0.56wt%C, were used to validate and verify the modelling assumptions. The model could be regarded as a semi-phenomenological approach with sufficient links between microstructure and the overall mechanical properties, and therefore offers good predictive capabilities. Its simplicity also allows a modular implementation in finite element-based metal forming simulations.

On Deformation Twinning in a 17.5%Mn–TWIP Steel: a Physically Based Phenomenological Model. A.Soulami, K.S.Choi, Y.F.Shen, W.N.Liu, X.Sun, M.A.Khaleel: Materials Science and Engineering A, 2011, 528[3], 1402-8