A new constitutive model within the framework of Chaboche model was
developed by improving the nonlinear isotropic hardening law and
kinematic hardening law with cyclic characteristic parameters. Strain
controlled creep-fatigue experiment of P92 steel with various strain
amplitudes and holding time were conducted under 600℃.The feature of the
cycle softening and stress relaxation were studied under the
creep-fatigue condition. The result shows that the effect of strain
amplitude on cyclic softening and stress relaxation behavior is
negligible, however the holding time has a greater impact on both.
According to the experimental data, the constitutive model of P92 under
creep-fatigue interaction was deduced, and the reliability of the model
was also verified, in which the cycle characteristics of P92 steel under
creep-fatigue was finely described.