A model for surface reliefs formation in bainite transformation mechanism

Abstract

The most recent and important research results of our group on the microstructure and transformation mechanism of bainite in both ferrous and non-ferrous alloys are reviewed. The objective and popular existence of three-dimensional superledges and nanometre scale edges were confirmed. It was discovered by scanning tunneling microscopy (STM) that the bainitic plates were composed of ultra fine structural units, and their surface reliefs and those associated with Widmanstätten 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) mechanism of bainite has further been described and applied to interpret the complicated multi-layer substructure. The model of multi-layer structure of bainite has been proposed.