Atomic arrangement of bainite/austenite interface was examined by high resolution electron microscopy in a Fe-2Si-1.4C alloy. Lattice transition region with an intermediate lattice structure between two phases, which was a characteristic feature of shear-type deformation, was not observed either between upper bainite and austenite or between lower bainite and austenite. However, high-density dislocations existed inside upper and lower bainites, which may be introduced as a result of lattice invariant shear deformation. Based on these experimental facts, a shear deformation assisted-diffusional transformation model was proposed for the bainitic transformation.

Atomic Arrangement of Interphase Boundary between Bainite and Austenite in Fe-Si-C Alloy. K.Ogawa, T.Sawaguchi, S.Kajiwara: Materials Transactions, 2010, 51[3], 455-62