Fatigue deformation accompanying dynamic strain aging in a pearlitic eutectoid steel

The effect of dynamic strain aging on the cyclic stress response and the fatigue life in a pearlitic eutectoid steel was studied. The temperature ranges at which dynamic strain aging takes place during strain-controlled fatigue deformation and monotonic tensile deformation were also examined. Marked cyclic hardening due to dynamic strain aging took place at temperatures between 473 and 573 K, whereas cyclic softening occurred at room temperature. At 523 K and at a strain rate of 3.3 × 10−3 s−1, the cyclic hardening was the most prominent and the fatigue life was shorter than that at room temperature by a factor of more than 2. At the given strain rate, dynamic strain aging during fatigue deformation occurred at lower temperatures in comparison with that during tensile deformation.