A dislocation model for the stress-strain behavior of dual phase steels
2008 (English)In: IDDRG 2008 International Conference, 2008Conference paper (Refereed)
The Bergström dislocation model is used to study the influence of coiling temperature after hot rolling on the mechanical properties of the cold rolled SSAB-grade Docol 800DP. Further, the anisotropy-effect for this type of steel, caused for instance by banding, is investigated. The physical dislocation model is based on the assumption that the work hardening behaviour is controlled by the creation, the immobilisation and the remobilisation of dislocations and it is demonstrated that all these processes are strongly influenced by the amount of hard martensite particles in DP-steels. The true strain to necking is a widely used tool for estimating the stretch formability of DP-steels. A detailed discussion regarding the influence of for instance friction stress, rate of dislocation remobilisation and mean free path of dislocation motion is presented. It is also indicated that the best stretch formability of DP-steel is obtained by minimising the quotient between the rate of work hardening at smaller strains with that at larger strains, close to the strain at necking.
Place, publisher, year, edition, pages
Strain hardening, Dislocation model, Dual-phase steel, Formability
Metallurgy and Metallic Materials
IdentifiersURN: urn:nbn:se:kth:diva-24978OAI: oai:DiVA.org:kth-24978DiVA: diva2:354776
QC 201010042010-10-042010-10-042010-10-04Bibliographically approved