Applications of crack growth models in life prediction of elevated temperature components

摘要

Creep and creep-fatigue crack growth behavior dominates the design life or remaining life of several thick-section poser plant components such as turbine rotors, casings, reheat and mean steam piping and headers. In this paper, the state-of-the-art proceduresfor predicting the crack growth life of these components are described. These procedures are based extensively on the recently developed time-dependent fracture mechanics concepts. Thus, the first part of the paper describes these concepts. The second part of the paper gives illustrative examples of these methods by considering specific components and estimating their remaining crack growth life. The paper also includes relevant crack growth rate data and creep deformation behavior on several materials used in power-plant applications necessary for these design or remaining crack growth life calculations.