Abstract: The Dual-Phase steels are
high strength steels with the formability of conventional steels
of much lower strength, the properties having been associated
with a two phase structure of ferrite and mariensite. The
failure mode of Dual-Phase steel sheet during the forming
processes was by plastic instability and voids formation.
Forming Limit Diagram (FLD) and the volume fraction of voids
were determined in a Mn-Si Dual-Phase steel with different
volume fraction of mariensite. The effect of voids formation on
the critical failure strain has been discussed with the aid of
damage mechanics. The critical failure strain along FLD is
described reasonably well by the equation derived, namely
Key words:
Dual-Phase steel Formability Forming limit diagram (FLD) Strain path Voids formation Stress triaxialty Damage mechanics Forming limit strain
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