Modelling Long Term Creep Deformation and Creep Damage and the Extrapolation Methods

Modelling long term creep deformation and creep damage is vital important for power generation industry as the Generation IV Nuclear Reactors are now expected to work for 60 years. This is due that the knowledge about long term creep deformation and creep damage required for safe and economical operation is unlikely to be directly obtained through experiments, due to the constraint of time and cost. However, the application of the traditionally obtained empirical based time-temperature parameter approach is not very successful, due to the stress breakdown phenomena. It is the authors view that the new approach must be mechanism-based and can be calibrated using short term experimental data to ensure its extrapolation credential. Following this thought, the authors have (1) proposed the modified shine law for minimum creep strain rate for wide range of stress, (2) developed creep cavitation damage model based on cavitation and the creep lifetime model. Here, we summarize such work first, then explore their extrapolation capabilities. It concludes with the author’s view on the future research topics. This paper orientates and steers research activities.