(b)
Figs.4: The determination of (a) isotropic parameters c andd by fitting of drag stress evolution to describe the yield
surface expansion with plastic deformation, and (b) kinematic parametersan and bn for description
of the movement of yield surface after material comes into yielding
using SSFS high temperature LCF test data for FV566 at 600 ℃.
Table 1: Optimized material parameters in the UVP model for FV566 at 600
℃.