The relative significance of internal damage mechanisms on the overall creep damage and ultimate failure of P91 steel

This paper reports research on the study of the relative significance of various internal creep damage mechanisms on the overall creep damage and lifetime of P91 steel. The study is essentially parametric investigation based on the individual internal creep damage mechanisms and phenomenological modelling of creep cavity damage. The simulated results do show the importance of the cavity damage among all the creep damage mechanisms. However, more importantly, it also points out the deficiency in the latest approach of phenomenological approach of modelling cavity damage over a wider stress range, and addresses the necessity of considering and incorporating the micromechanics/mechanism of nucleation, growth, coalescence into the creep damage constitutive modelling work. This paper contributes to the knowledge and method for creep damage mechanics.