Thermodynamic-Mechanical Modeling of Strain-Induced α′-Martensite Formation in Austenitic Cr–Mn–Ni As-Cast Steel


  • The authors would like to thank all of the staff involved in the collaborative research centre 799, especially Dipl.-Wi.-Ing. Steffen Wolf for the carrying out of the tensile tests, and the German Research Foundation (DFG) for financial support of these investigations.



The microstructure evolution during deformation and the mechanical behavior of an austenitic Cr–Mn–Ni as cast steel are investigated at various temperatures. The deformation-induced twinning and ϵ/α′-martensite formation – the TWIP and TRIP effects – occur in the investigate steel depending on the deformation temperature. For characterization and illustration of the TRIP/TWIP effects the STT and DTT diagrams are developed. Finally, the α′-martensite nucleation threshold is determined, and an equation is proposed to describe the volume fraction of strain-induced α′-martensite as a function of the total driving force.