A robust model for creep-fatigue life assessment

High temperature components subjected to long term cyclic operation will acquire life-limiting damage from both creep and fatigue. A new robust model for creep-fatigue life assessment is proposed with a minimal set of fitting constants, and without the need to separate creep and fatigue damage or life fractions. The model is based on the creep rupture behaviour of the material with a fatigue correction described by hold time (in tension) and total strain range at temperature. The model is shown to predict the observed creep-fatigue life of ferritic steel P91, austenitic steel 316FR, and Ni alloy A230 with a scatter band close to a factor of 2. (C) 2012 Elsevier B.V. All rights reserved.