Abstract: High temperature low-cycle fatigue test with hold time ranging from 10 s to 60 s are performed on 30Cr1Mo1V under a fully reversed axial total strain control mode at 540 ℃and 565 ℃. The strain amplitudes are 0.6% ~1.2%, the waveforms are symmetrical trapezium. The relaxation phenomena and the strain-life laws are investigated. Several commonly used fatigue-creep life prediction methods are chosen to analyze the experimental data. The scatter band factor and standard deviation are used to test validity of these life prediction methods. The results show that the ratios of the first and the third stage are increasing whereas the ratio of the second stage is decreasing with the increasing strain. The relaxation ratios are almost the same during tensile hold time and compress hold time with stress for reference. The linear damage summation method and the strain range partitioning method have higher precision, whereas the strain energy partitioning method and the modified frequency Manson-Coffin method are weaker in life-prediction. In addition, life prediction formula of this material are presented of these life-prediction modes.

Key words: 30Cr1Mo1V steel, Creep, Fatigue, Low-cycle fatigue, Strain-controlled