Kinetics of the loading surface of a material gives precious information on the level of the hardening of the material. This paper is concerned with the evolution of the loading surface during successive actions, such as: (i) plastic deformation, (ii) annealing of the pre-strained specimen, and (iii) secondary creep of the treated material. The analysis of the loading surface is carried out in terms of the synthetic theory of irrecoverable deformation.