The Role of Phase Hardness Differential on the Non-uniform Elongation of a Ferrite-Martensite Dual Phase Steel

Soudip Basu, Balila Nagamani Jaya, Anirban Patra, Sarbari Ganguly, Monojit Dutta, Anton Hohenwarter, Indradev Samajdar

Publikation: Beitrag in FachzeitschriftArtikelForschungBegutachtung

1 Zitat (Scopus)

Abstract

This study involved a commercial hot-rolled dual-phase (DP) steel consisting of martensite (~10 pct) and ferrite phases. The harder lath martensite was located at the grain boundaries and triple junctions of the equiaxed ferrite grains. Tempering and high-pressure torsion (HPT) were used to alter the phase hardness differential ∆H (where ΔH=HMartensite−HFerrite) of the DP. The relationship between ∆H and non-uniform elongation, εNU, or post-necking ductility under tensile deformation, was then explored. Tempering softened predominantly the martensite, while HPT increased the ferrite hardness. Both led to a reduction in ∆H. A drop in ∆H in the tempered DP resulted in a steady increase and eventual saturation in εNU. On the other hand, a ∆H decrease in the HPT specimens showed an initial increase in εNU followed by a drop. Strain analysis, with optical digital image correlation during tensile deformation of the tempered DP samples, clearly related the formation of strain localization with ∆H. In particular, severity of strain localization during necking scaled linearly with ∆H. This study thus brought out a potential relationship among the phase hardness differential (∆H), severity of strain localizations and post-necking ductility (εNU).
OriginalspracheEnglisch
Seiten (von - bis)4018-4032
Seitenumfang15
FachzeitschriftMetallurgical and materials transactions. A, Physical metallurgy and materials science
Jahrgang52.2021
Ausgabenummer9
Frühes Online-Datum15 Juli 2021
DOIs
PublikationsstatusVeröffentlicht - Sept. 2021

Bibliographische Notiz

Funding Information:
The authors thank Tata TMSteel for support and research collaboration. Support from SERB-IRRD (Science and Engineering Research Board-Industrially Relevant Research and Development) was critical and is acknowledged. Finally, acknowledgement is also due for the use of National Facility of Texture and OIM, TEM Laboratory of the Sophisticated Analytical Instrument Facility (SAIF), nanoindentation laboratory and mechanical testing facilities of IIT Bombay. On behalf of all authors, the corresponding author states that there is no conflict of interest.

Publisher Copyright:
© 2021, The Minerals, Metals & Materials Society and ASM International.

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