English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Experimental findings in the literature reveal that DP steels with identicalstrength and composition, but different microstructures, exhibit inconsistenttrends under either necking-controlled or damage-controlled ductility tests. Aspecial case of this phenomenon is referred to in the forming community as thecut-edge failure or edge cracking issue of DP steels. It is observed thatglobally ductile microstructures are prone to premature damage at cut edgeswhile a comparatively less ductile DP steel performs better under the locallyapplied deformation at such edges. In this paper, a systematical statisticalstudy is conducted to analyse this paradox from a micromechanical point ofview. The obtained results qualitatively confirm the experimental observationsand allowed us to explain/rationalize them, as follows. To reach a highernecking-controlled ductility, i.e. global ductility, the mechanical contrastbetween ferrite and martensite must be increased. Since martensite reveals avery high initial hardening and fast saturation, activation of martensiteplasticity will lead to early necking in the microstructure and shouldtherefore be avoided; a high mechanical phase contrast has this effect.However, at the same time a higher mechanical phase contrast is detrimental forthe local ductility. More heterogeneity in the microstructure causes thegeneration of higher local plastic strains and triaxial stresses which leads toearly damages. Therefore, in DP steel, increasing the global ductility may comeat the expense of decreasing local ductility, and vice versa. The martensitehardening behavior is the main factor governing this phenomenon, and thereforealso constitutes the key to processing improved steels that combine the best ofboth.

On the critical role of martensite hardening behavior in the paradox of local and global ductility in dual-phase steels