Microstructure Evolution during Deformation Induced Ferrite Transformation

摘要

The microstructure evolution during deformation induced ferrite transformation (DIFT) for a Nb microalloyed low carbon steel was investigated by thermal simulating tests, and then compared with the microstructure evolution during continuous cooling transformation of deformed austenite. Results illustrate that DIFT can be divided into three stages: the first stage with lower nucleation rate, the second stage with higher nucleation rate and the third stage with lower nucleation rate. DIFT is a nucleation dominant process, i.e. the γ→α transformation is mainly accomplished by continuous nucleation, whereas the CCT of deformed austenite is a grain growth dominant process.