Design of a constitutive model based on the evolution of creep cavities damage for 9Cr-1Mo steel

Abstract

Considering the impact creep cavity evolution damage of 9Cr-1Mo steel, a new creep constitutive model was established based on the damage-coupled Norton equation and the strain hardening term in the theta projection method model, and the parameters were solved by optimization technique. The creep behavior was compared with that of the Kachanov-Robotnov model. According to the simulation results, the proposed constitutive model can represent the strengthening phenomenon during the first creep stage of 9Cr-1Mo steel. It provides a more accurate description of the behavior during the three creep periods.