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Understanding the damage initiation and growth mechanisms of two DP800 dual phase grades

Tian, Chunhua ; Kusche, Carl F. 1,2; Medina, Angelica 1; Lee, Subin 1; Wollenweber, Maximilian A.; Pippan, Reinhard; Korte-Kerzel, Sandra; Kirchlechner, Christoph 1
1 Institut für Angewandte Materialien – Werkstoff- und Grenzflächenmechanik (IAM-MMI), Karlsruher Institut für Technologie (KIT)
2 Rheinisch-Westfälische Technische Hochschule Aachen (RWTH Aachen)

Abstract:

Dual phase (DP) steels are amongst the most widely used structural steels for automotive applications. It is essential to understand the damage initiation and damage growth in these high strength steels and further shed light on improving mechanical properties. In this work, two DP800 dual phase grades are investigated, which exhibit identical ultimate tensile stress but significantly different elongation in the uniaxial tensile test. To explain the difference in ductility, particularly described by uniform elongation, we investigate the damage initiation and growth mechanisms by analyzing microstructural changes upon deformation, such as voids, dislocation structures and the grain morphology. Furthermore, ferrite micropillars in pre-strained samples are tested in situ to capture the strain hardening capability of ferrite. We found that the DP steel with harder martensite and softer ferrite exhibits more damage initiation sites after deforming to an identical strain. However, void growth is much slower compared to the DP steel grade with fewer initiation sites. We explain the suppressed void growth by significant strain-hardening of ferrite surrounding the voids, which is observed in the micropillar compression experiments. ... mehr


Verlagsausgabe §
DOI: 10.5445/IR/1000167373
Veröffentlicht am 16.01.2024
Originalveröffentlichung
DOI: 10.1016/j.matdes.2024.112630
Scopus
Zitationen: 1
Web of Science
Zitationen: 1
Dimensions
Zitationen: 2
Cover der Publikation
Zugehörige Institution(en) am KIT Institut für Angewandte Materialien – Werkstoff- und Grenzflächenmechanik (IAM-MMI)
Publikationstyp Zeitschriftenaufsatz
Publikationsmonat/-jahr 02.2024
Sprache Englisch
Identifikator ISSN: 0264-1275
KITopen-ID: 1000167373
HGF-Programm 43.31.01 (POF IV, LK 01) Multifunctionality Molecular Design & Material Architecture
Erschienen in Materials & Design
Verlag Elsevier
Band 238
Seiten Art.-Nr. 112630
Vorab online veröffentlicht am 03.01.2024
Nachgewiesen in Dimensions
Scopus
Web of Science
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