Fatigue at High Temperature-Prediction and Interpretation

This lecture reviews the significant developments in fatigue over the last twenty years as they pertain to the prediction of life in high-temperature service. Particular attention is given to the interpretation of fatigue test results for both low and high cycle fatigue at room and elevated temperatures. Emphasis is given to such effects as environment, frequency and strain rate, metallurgical factors, wave shape and thermal cycling, and some attempt is made to sort out their relative importance. Applicability of low cycle fatigue information to notch geometries is discussed. Lastly considered is the significance of these several factors to the current state of life prediction as well as to future directions for development of this important topic.