Influence of ε-martensite and austenite on mechanical properties by intercritical annealing in 0.1C-11Mn medium manganese steel

We studied the effect of microstructure by intercritical annealing of medium manganese steel in aspect of mechanical properties. The microstructure and phase transformation was characterized by using scanning electron microscope, electron backscattering diffraction and transmission electron microscope. The experimental results showed that ε-martensite appeared as acicular at the austenite grain boundary and phase interface. The volume of ε-martensite and austenite firstly increased then decreased with the increment of intercritical annealing. The yield strength also showed a similar trend in correspondence with ε-martensite. Therefore, in addition traditional strengthening mechanism and austenite, ε-martensite may affect the yield strength.