Temperature effect on the low-cycle fatigue behavior of type 316L stainless steel: Cyclic non-stabilization and an invariable fatigue parameter

The temperature effect on the cyclic non-stabilization of cold-worked 316L stainless steel during low-cycle fatigue deformation was investigated. The material underwent additional cyclic hardening at room temperature and in the temperature range of 250–600 °C; the hardening at room temperature came from plasticity-induced martensite transformation and the hardening in the temperature range of 250–600 °C was attributed to dynamic strain aging. These hardening mechanisms competed with the cyclic softening induced by dynamic recovery, which is generally predominant in cold-worked materials, and this led to the cyclic non-stabilization of the material. Three fatigue parameters: the stress amplitude, plastic strain amplitude and plastic strain energy density, were evaluated to find an invariable fatigue parameter. The results revealed that the plastic strain energy density was stabilized at the early stage of fatigue life and nearly invariant through the entire life.