Effect of kinematic stability of initial orientation on deformation heterogeneity and ductile failure in duplex stainless steel during uniaxial tension

The crystal plasticity finite element method (CPFEM) was used to investigate the effect of the kinematic stability of the initial orientations on the deformation heterogeneity and ductile failure of ferrite and austenite phases in duplex stainless steel (DSS) during uniaxial tension. The individual stress–strain relationships of ferrite and austenite phases in DSS were evaluated via in situ neutron diffraction in combination with the CPFEM. A CPFEM based on the volume elements (VEs) of a unit cell of DSS with a regular banded microstructure demonstrated that the kinematic stability of the initial orientations significantly affected the deformation heterogeneity and ductile failure in the constituent phases in VEs during uniaxial tension. The regions susceptible to ductile failure were identified as being in the austenite phase near the phase boundaries of ferrite and austenite.