Dual-Phase Steels: Advances in Microstructure-Oriented Processing and Micromechanically Guided Design

Dual-phase (DP) steel is the flagship of advanced high-strength steels, which were the first among various candidate alloy systems to find application in weight-reduced automotive components.

A compilation of damage mechanism analyses showing the effects of ferrite grain size SF and martensite volume fraction VM on the reported damage regimes: martensite cracking (DM) and martensite-ferrite decohesion (DM-F). F and M indicate ferrite and martensite, respectively. — A compilation of damage mechanism analyses showing the effects of ferrite grain size S_F and martensite volume fraction V_M on the reported damage regimes: martensite cracking (D_M) and martensite-ferrite decohesion (D_M-F). F and M indicate ferrite and martensite, respectively.

Annu. Rev. Mater. Res. 45: 391-431; Max-Planck-Institut für Eisenforschung GmbH1

A compilation of damage mechanism analyses showing the effects of ferrite grain size S_F and martensite volume fraction V_M on the reported damage regimes: martensite cracking (D_M) and martensite-ferrite decohesion (D_M-F). F and M indicate ferrite and martensite, respectively.

Annu. Rev. Mater. Res. 45: 391-431; Max-Planck-Institut für Eisenforschung GmbH1

On the one hand, this is a metallurgical success story: Lean alloying and simple thermomechanical treatment enable use of less material to accomplish more performance while complying with demanding environmental and economic constraints. On the other hand, the enormous literature on DP steels demonstrates the immense complexity of microstructure physics in multiphase alloys: Roughly 50 years after the first reports on ferrite-martensite steels, there are still various open scientific questions. Fortunately, the last decades witnessed enormous advances in the development of enabling experimental and simulation techniques, significantly improving the understanding of DP steels. This review provides a detailed account of these improvements, focusing specifically on (a) microstructure evolution during processing, (b) experimental characterization of micromechanical behavior, and (c) the simulation of mechanical behavior, to highlight the critical unresolved issues and to guide future research efforts.