LIFE ESTIMATION METHOD BASED ON CREEP-FATIGUE INTERACTION.

A series of creep-fatigue interaction tests was conducted in order to evaluate a criterion for failure taking into account the detrimental effect caused by the time dependent process. From the test data on commonly used high temperature materials for gas turbine and diesel engine in air, hydrogen gas and corrosive ash, we proposed a life estimation method under the combined creep-fatigue loadings. This method based on linear cumulative creep damage expressed by the equivalent hold time is stress-dependent and independent of loading modes. We confirm by this method that the correlation between experimental data or available data in literatures and estimation is quite good for several types of loadings.