A model for surface reliefs formation in bainite transformation mechanism

The most recent and important research results of our group on the microstr ucture and transformation mechanism of bainite in both ferrous and non-ferr ous alloys are reviewed. The objective and popular existence of three-dimen sional superledges and nanometre scale edges were confirmed. It was discove red by scanning tunneling microscopy (STM) that the bainitic plates were co mposed of ultra fine structural units, and their surface reliefs and those associated with Widmanstatten ferrite were tent-shaped. Carbides nucleated in the matrix and grow toward austenite and the model of carbide formation was provided. The sympathetic nucleation and ledgewise growth (SNLG) mechan ism of bainite has further been described and applied to interpret the comp licated multi-layer substructure. The model of multi-layer structure of bai nite has been proposed.