Numerical Prediction of the Long Term Creep Crack Growth Behaviour in Type 316H Stainless Steel

Abstract

Life assessment of Type 316H stainless steel (SS) is of great concern to industry due to the widespread use of this material in power plant components that often operate at a temperature of around 550 °C. An important issue to be understood and considered in the life assessment of 316H components is the creep deformation and crack growth behaviour of this material in short term and long term operation times. Due to the limited long term test data available in the literature (i.e. [1, ), a new technique have been recently developed to estimate uniaxial creep ductility trends and subsequently creep crack growth (CCG) behaviour of the material at low load levels [. In this new method the creep ductility trends have been estimated as a function of the applied stress normalised by the temperature dependent 0.2% proof stress of the material, σ/σ0.2, to include the plasticity effects on the creep deformation behaviour of the material. These trends have been implemented in finite (FE) simulations to predict the CCG behaviour of 316H in intermediate and long term tests at 550 °C and provisional results are presented in [.