Study on the Creep-Fatigue Interaction Behavior of 1Cr11Ni2W2MoV Steel.

In order to investigate the creep-fatigue interaction of 1Cr11Ni2W2MoV steel, strain-controlled low-cycle fatigue tests were performed at various strain ranges with fully reversible cycle of triangular waveform at 500°C. In addition, different hold times were introduced at the maximum tensile strain to investigate the impact of creep damage on fatigue life. Fracture surfaces and axial section were evaluated in terms of crack growth behavior and propagation path. The creep-fatigue life decreased with increasing hold time. It was observed that cyclic softening effect intensified with tensile holding. Crack initiation and growth behavior changed in relation to hold time that exceeded 60 s at a strain range of 1.2 %, which led to premature failure. Under the present test conditions, a good description of fatigue life was provided by the model based on inelastic strain energy density. [ABSTRACT FROM AUTHOR]