Microstructural Characteristics and Strengthening Mechanisms of Ferritic–Martensitic Dual-Phase Steels: A Review

Abstract

Ferritic–martensitic dual-phase (DP) steels are prominent and advanced high-strength steels (AHSS) broadly employed in automotive industries. Hence, extensive study is conducted regarding the relationship between the microstructure and mechanical properties of DP steels due to the high importance of DP steels in these industries. In this respect, this paper was aimed at reviewing the microstructural characteristics and strengthening mechanisms of DP steels. This review article represents that the main microstructural characteristics of DP steels include the ferrite grain size (FGS), martensite volume fraction (MVF), and martensite morphology (MM), which play a key role in the strengthening mechanisms and mechanical properties. In other words, these can act as strengthening factors, which were separately considered in this paper. Thus, the properties of DP steels are intensely governed by focusing on these characteristics (i.e., FGS, MVF, and MM). This review article addressed the improvement techniques of strengthening mechanisms and the effects of hardening factors on mechanical properties. The relevant techniques were also made up of several processing routes, e.g., thermal cycling, cold rolling, hot rolling, etc., that could make a great strength–ductility balance. Lastly, this review paper could provide substantial assistance to researchers and automotive engineers for DP steel manufacturing with excellent properties. Hence, researchers and automotive engineers are also able to design automobiles using DP steels that possess the lowest fuel consumption and prevent accidents that result from premature mechanical failures.

Nanoscale Tribological Properties of Nanostructure Fe3Al and (Fe,Ti)3Al Compounds Fabricated by Spark Plasma Sintering Method

“…In this test, the residual depth is an appropriate criterion for evaluating the wear resistance of the material. This test is frequently used to compare the wear resistance of various materials processed in different conditions [55][56][57][58][59][60][61][62][63][64][65][66][67][68][69][70][71][72][73]. The AFM images from longitudinal scratches of the bulk As can be seen, the residual depth of the Fe 3 Al compound is larger than that of the (Fe,Ti) 3 Al sample.…”

Influence of pre‐strain and bake hardening on the static and fatigue strength of a DP600 steel sheet

“…Continuous yielding and low yield to tensile strength ratio are a consequence of the high density of mobile dislocations in ferrite created during austenite‐martensite transformation 5,6 . The behavior of DP steels is strongly related with their composite microstructure, consisting in hard martensite particles dispersed in a soft ferrite matrix, because of the heterogeneous strain distribution in the two phases 7–9 . In general, tensile strength is improved with increasing martensite content, while its dispersion determines ductility 6,10–13 .…”

Influence of pre-strain and bake hardening on the static and fatigue strength of a DP600 steel sheet

“…Continuous yielding and low yield to tensile strength ratio are a consequence of the high density of mobile dislocations in ferrite created during austenite-martensite transformation 5;6 . The behavior of DP steels is strongly related with their composite microstructure, consisting in hard martensite particles dispersed in a soft ferrite matrix, because of the heterogeneous strain distribution in the two phases [7][8][9] . In general, tensile strength is improved with increasing martensite content, while its dispersion determines ductility 5;10-13 .…”