Method for Evaluation of Remaining Life in High Temperature Component Based on Numerical Simulation of Small Crack Initiation and Growth in Creep-Fatigue

In order to achieve the objective of securing the reliability of high-temperature components, it is necessary to establish a method for predicting the remaining life of their materials subjected to severe creep-fatigue damage. It was reported by the authors that multiple small cracks initiated along grain boundaries on the specimen surface at the very early stage of life in creep-fatigue and their growth and coalescence formed the main crack which induced the failure. Moreover, the process of small crack initiation and growth showed random behavior due to microstructural inhomogeneity. A stochastic model was proposed and the failure process was numerically simulated by means of the Monte Carlo method. This paper provides a scheme of the small-crack-simulation-method for the evaluation of remaining life of the materials in high-temperature components, which is an integration of our previous studies and is summarized in a flow chart.