Analysis of Dislocation Structures in Ferritic and Dual Phase Steels Regarding Continuous and Discontinuous Loading Paths

  • Gregory GersteinEmail author
  • Till Clausmeyer
  • Florian Gutknecht
  • A. Erman Tekkaya
  • Florian Nürnberger
Conference paper
Part of the The Minerals, Metals & Materials Series book series (MMMS)


In sheet-bulk metal forming processes the hardening behavior of the material depends on the sequence of deformation steps and the type of deformation. Loading path changes induce transient hardening phenomena. These phenomena are linked to the formation and interaction of oriented dislocation structures. The aim of this study is to investigate the effect of continuous and discontinuous loading path changes on the dislocation microstructure in ferritic and ferritic-martensitic dual-phase steel, respectively. For the experiments a biaxial test stand was used, which permits to continuously change the load from tension to shear. In the ferrite single-phase steel transmission-electron microscopy reveals a reduced evolution of oriented dislocation structures for continuous loading path changes compared to discontinuous loading path changes. This evolution is further decreased in dual-phase steel compared to the ferritic steel. Microstructural results for the ferritic steel are accompanied by simulation results with a transient hardening model.


Sheet-bulk metal forming Dislocation structures Material modeling Parameter identification 



Funding by the German Research Foundation (DFG) within the scope of the Transregional Collaborative Research Centre on sheet-bulk metal forming (SFB/TR 73) in the subproject C4 ‘Analysis of load history dependent evolution of damage and microstructure for the numerical design of sheet-bulk metal forming processes’ is highly acknowledged.


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Copyright information

© The Minerals, Metals & Materials Society 2017

Authors and Affiliations

  • Gregory Gerstein
    • 1
    Email author
  • Till Clausmeyer
    • 2
  • Florian Gutknecht
    • 2
  • A. Erman Tekkaya
    • 2
  • Florian Nürnberger
    • 1
  1. 1.Institut für Werkstoffkunde (Materials Science)Leibniz Universität HannoverHannoverGermany
  2. 2.Institute of Forming Technology and Lightweight ConstructionTU Dortmund UniversityDortmundGermany

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