Design of Novel Bainitic Steels: Moving from UltraFine to Nanoscale Structures

The concepts of phase transformation theory can be exploited to design nanostructured steels that transform to bainite at temperatures as low as 150A degrees C. The microstructure obtained is so refined that it is possible to achieve strength in excess of 2.5 GPa in a material that has considerable toughness (40 MPam(1/2)). Such a combination of properties has never been achieved before with bainite. A description of the characteristics and significance of this remarkable microstructure in the context of the mechanism of transformation is provided.