Failure mechanisms of high temperature components in power plants

The principal mechanisms of failure of high temperature components include creep, fatigue, creep-fatigue, and thermal fatigue. In heavy section compon ents, although cracks may initiate and grow by these mechanisms, ultimate f ailure may occur at low temperatures during startup-shutdown transients. He nce, fracture toughness is also a key consideration. Considerable advances have been made both with respect to crack initiation and crack growth by th e above mechanisms. Applying laboratory data to predict component life has often been thwarted by inability to simulate actual stresses, strain cycles , section size effects, environmental effects, and and long term degradatio n effects. This paper will provide a broad perspective on the failure mecha nisms and life prediction methods and their significance in the context uti lity deregulation. [S0094-4289(00)00103-1].