Dual-Phase Steels: The First Family of Advanced High Strength Steels

Dual-Phase steels have been marketed since the early 1990s and are widely used in the sector of automotive and truck construction. They make up the majority of so-called modern or first-generation AHSS (Advanced High Strength Steels). The superior balance between strength, formability and ductility of DP steels comes from their particular composite microstructure, consisting mainly of ferrite and martensite. This article traces first the history of DP steels from their discovery in the 1960s to the most recent industrial developments. It then addresses current knowledge about the link between the microstructure and mechanical properties of these alloys. The mechanisms governing their microstructure morphogenesis are described in a third part. During those discussions, the contributions of metallurgical and micromechanical modeling in DP science shall be highlighted. Finally, the active fields of research and the anticipated developments of DP technologies will be evoked.