Microstructure evolution and strain hardening behavior of thermomechanically processed low-C high-manganese steels: an effect of deformation temperature

Abstract Effects of reduced (– 40 °C), ambient (20 and elevated (200 °C) deformation temperatures on the microstructure evolution strain hardening behavior two low-C thermomechanically processed high-manganese steels were studied. The was characterized by means scanning electron microscopy (SEM), backscatter diffraction (EBSD), transmission (TEM) techniques. temperature-dependent tendency austenite to strain-induced ε/α′-martensitic transformation mechanical twinning qualitatively quantitatively assessed using EBSD technique. steel containing 26 wt% Mn showed beneficial strength–ductility balance at temperature -40 °C due intense Transformation-Induced Plasticity (TRIP) effect which resulted in formation significant ε- α′-martensite fractions during tensile deformation. properties 27 more 200 occurrence Twinning-Induced (TWIP) expressed presence fraction twins. Moreover, highest °C, evidence thermally activated processes affecting higher identified described.