Low-Cycle Fatigue of a Nickel Superalloy at Various Loading Frequencies

The influence of the deformation frequency in a low-cycle region (f = 1–3 Hz, N ≤ 10⁵ cycles) on the fatigue life characteristics of a nickel superalloy has been studied. Tests are performed under strain-controlled loading conditions at temperatures of 25 and 700°C. The influence of the deformation frequency on the fatigue life is found to be most significant at an elevated temperature. The main difference in the character of fracture consists in a flatter fracture surface relief and a longer fatigue crack front at an increased loading frequency.