Influence of prior austenite grain size on the critical strain for completion of DEFT through hot compression test

A low carbon steel was used to determine the critical strain ε c for completion of deformation enhanced ferrite transformation (DEFT) through a series of hot compression tests. In addition, the influence of prior austenite grain size (PAGS) on the critical strain was systematically investigated. Experimental results showed that the critical strain is affected by PAGS. When γ→α transformation completes, the smaller the PAGS is, the smaller the critical strain is. The ferrite grains obtained through DEFT can be refined to about 3 µm when the DEFT is completed.