Failure Mechanisms of High Temperature Components in Power Plants

Abstract

The principal mechanisms of failure of high temperature components include creep, fatigue, creep-fatigue, and thermal fatigue. In heavy section components, although cracks may initiate and grow by these mechanisms, ultimate failure may occur at low temperatures during startup-shutdown transients. Hence, fracture toughness is also a key consideration. Considerable advances have been made both with respect to crack initiation and crack growth by the 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 long term degradation effects. This paper will provide a broad perspective on the failure mechanisms and life prediction methods and their significance in the context utility deregulation. [S0094-4289(00)00103-1]