Low cycle fatigue life prediction for GH4133 at 550℃ based on power-exponent function

Abstract

The low cycle fatigue tests of GH4133 superalloy are carried out under total axial strain at 550℃. The relationships of cyclic stress-strain and strain-life are analyzed. The low cycle fatigue test data of GH4133 superalloy are processed by Manson-Coffin method. When experimental data is processed, the relationship between plastic strain and failure reverse number presents nonlinear in the double logarithmic coordinates. Therefore, there must be some prediction error by Manson-Coffin method. In order to solve the problem, a new method based on power-exponent function is developed. The results of life prediction are given by using new method at the same time. The results showed that two methods chosen were able to give a reasonable life prediction result for GH4133 superalloy. Prediction accuracy within ± 1.5 times scatter band. In order to verify the applicability of power-exponent function model, the investigation gives the model performances contrast results of several materials. The results of life prediction showed new method gave better results with the smaller scatter band and standard deviation than Manson-Coffin method.The life prediction capability of new methods proves more effective and accurate than Manson-Coffin method.