Life assessment for high temperature components - Techniques and models

Extension of service lives of high temperature components based on health assessment and remaining life calculation data has been a major research and field activity over the past two decades. The concern has been focused on the development of appropriate methodologies and life prediction models that may be used with reasonable accuracy to maintain safety and integrity of plant components. A multitude of models and methodologies are proposed and used in industries for various component specific applications. A review is made here on the progress of development on the subject in general. High temperature component failure mechanisms are identified to be creep, creep fatigue and thermal fatigue. The currently available techniques are empirical in nature and have achieved varying degrees of success. The potential methods demand further in-depth research to be free from some uncertainties and ambiguities as outlined.