Transformation behavior of retained austenite under different deformation modes for low alloyed TRIP-assisted steels

Transformation behavior of retained austenite of a 0.21C–1.5Si–1.0Mn (weight%) transformation induced plasticity (TRIP)-assisted steel during uniaxial tension, biaxial stretching, and plane strain deformation has been investigated by experiments. It has indicated that more austenite transforming to martensite in plane strain tension than in biaxial stretching and uniaxial tension. A model describing the relationship between the volume fraction of retained austenite, equivalent strain and deformation mode has been summarized from experimental data. And then some published data are extracted to verify the model. The influence of strain rate on transformation rate is also discussed in the end of the paper. It is concluded that TRIP steels should be deformed with appropriate strain rate and suitable strain path to make full use of the TRIP effect.