Dual-criterion diagram methods for designing and assessing the life and strength of high-temperature rotating components

A method for establishing a dual-criterion diagram for designing and assessing the life and strength of a high-temperature rotating component comprising a material, the method comprising the following steps:

• S1, conducting high-temperature fatigue and creep tests using the high-temperature rotating component material, wherein the high-temperature fatigue test is conducted using an electromagnetic resonance high-frequency testing machine including a heating device and operated in a stress control mode within a frequency range of 50-250 Hz (inclusive) and the high-temperature creep test is conducted using a lever type mechanical creep testing machine including a heating device and operated in a stress control mode;
• S2, obtaining fatigue strengths of the material for a given life from fatigue data generated by the high-temperature fatigue test at stress ratios of R=−1 and R=0, wherein a data scattering factor is taken into account by giving a safety factor when the fatigue data are converted into design data;
• S3, obtaining creep rupture strength data of the high-temperature rotating component material for a given life from results of the creep test;
• S4, plotting a fatigue portion of the dual-criterion diagram for designing and assessing the life and strength of the high-temperature rotating components from the fatigue data of the high-temperature rotating component material obtained in step S2, so as to obtain a straight line with an abscissa axis representing the mean stress and an ordinate axis representing the stress amplitude;
• and
• S5, plotting a creep portion of the dual-criterion diagram for designing and assessing the life and strength of the high-temperature rotating component from the creep rupture strength data of the high-temperature rotating component material obtained in step S3, wherein the creep portion is a cutoff line of the straight line in step S4, and a straight line perpendicular to the abscissa axis representing mean stress.