Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
A dislocation based theory for the deformation hardening behavior of DP-steels: Impact of martensite content and ferrite grain size
Product Development/Materials Research, Borlänge, Sweden.
2010 (English)In: Journal of Metallurgy, ISSN 1687-9465, E-ISSN 1687-9473, Vol. 2010, no 647198Article in journal (Refereed) Published
Abstract [en]

A dislocation model, accurately describing the uniaxial plastic stress-strain behavior of dual phase (DP) steels, is proposed and the impact of martensite content and ferrite grain size in four commercially produced DP-steels is analyzed. It is assumed that the plastic deformation process is localized to the ferrite. This is taken into account by introducing a non-homogeneity parameter, f(ε), that specifies the volume fraction of ferrite taking active part in the plastic deformation process. It is found that the larger the martensite content the smaller the initial volume fraction of active ferrite which yields a higher initial deformation hardening rate. This explains the high energy absorbing capacity of DP-steels with high volume fractions of martensite. Further, the effect of ferrite grain size strengthening in DP-steels is important. The flow stress grain size sensitivity for DP-steels is observed to be 7 times larger than that for single phase ferrite.

Place, publisher, year, edition, pages
2010. Vol. 2010, no 647198
Keyword [en]
DP-steels, dislocation model, inhomogeneous deformation hardening, martensite content, ferrite grain size
National Category
Metallurgy and Metallic Materials
Identifiers
URN: urn:nbn:se:kth:diva-24980DOI: 10.1155/2010/647198OAI: oai:DiVA.org:kth-24980DiVA: diva2:354797
Note

QC 20101004. Updated from submitted to Epub ahead of print, 20120315. Updated from Epub ahead of print to print 20131126

Available from: 2010-10-04 Created: 2010-10-04 Last updated: 2017-12-12Bibliographically approved
In thesis
1. Structure and mechanical properties of dual phase steels: An experimental and theoretical analysis
Open this publication in new window or tab >>Structure and mechanical properties of dual phase steels: An experimental and theoretical analysis
2010 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

The key to the understanding of the mechanical behavior of dual phase (DP) steels is to a large extent to be found in the microstructure. The microstructure is in its turn a result of the chemical composition and the process parameters during its production. In this thesis the connection between microstructure and mechanical properties is studied, with focus on the microstructure development during annealing in a continuous annealing line. In-line trials as well as the lab simulations have been carried out in order to investigate the impact of alloying elements and process parameters on the microstructure. Further, a dislocation model has been developed in order to analyze the work hardening behavior of DP steels during plastic deformation.

From the in-line trials it was concluded that there is an inheritance from the hot rolling process both on the microstructure and properties of the cold rolled and annealed product. Despite large cold rolling reductions, recrystallization and phase transformations, the final dual phase steel is still effected by process parameters far back in the production chain, such as the coiling temperature following the hot rolling.

Lab simulations showed that the microstructure and consequently the mechanical properties are impacted not only by the chemical composition of the steel but also by a large number of process parameters such as soaking temperature, cooling rate prior to quenching, quench and temper annealing temperature.

 

Place, publisher, year, edition, pages
Stockholm: KTH, 2010
Keyword
Dual phase steels, continuous annealing, dilatometry, microstructure, mechanical properties, process parameters, dislocation model, plastic deformation
National Category
Metallurgy and Metallic Materials
Identifiers
urn:nbn:se:kth:diva-24869 (URN)
Public defence
2010-10-27, Nya konferensrummet, Brinellvägen 23, Stockholm, 16:20 (English)
Opponent
Supervisors
Note
QC 20101004Available from: 2010-10-04 Created: 2010-09-28 Last updated: 2010-10-06Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text

Search in DiVA

By author/editor
Granbom, Ylva
In the same journal
Journal of Metallurgy
Metallurgy and Metallic Materials

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 180 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf