Use the Annealing subnode to
Plasticity to reset plastic hardening variables (equivalent plastic strain and, in the presence of kinematic hardening, the back stress). The plastic hardening variables are reset when the temperature exceeds a specified value that you define.
The Annealing node requires the Nonlinear Structural Materials Module. For details, see
www.comsol.com/products/specifications/
Enter the Annealing temperature. This is the temperature above which the plastic hardening variables are reset.
Physics tab with Plasticity node selected in the model tree: