A study of high temperature low cycle fatigue life prediction for two superalloys

The high temperature low cycle fatigue tests of dz22 superalloy and k403 superalloy are carried out under strain controlled. the low cycle fatigue test data of dz22 superalloy at 850°c and k403 superalloy at 750°c are processed by coffin-manson method. when experimental data is processed,negative or small plastic strain values often appear and the results of life prediction fail to meet the needs of the designer. in order to solve the problem,a new method based on stress fatigue and coffin-manson method is developed,the results of life prediction are given by using new method at the same time. the results showed that new method is more accurate than the coffin- manson method. the life prediction capability of two methods for dz22 superalloy proves more effective than k403 superalloy.