Deformation mechanism and cyclic stress response of Zircaloy-4 alloy cladding tube during low cycle fatigue at room temperature

This work systematically investigated the deformation mechanism and cyclic stress response behavior of Zircaloy-4 alloy cladding tube at room temperature. Low cyclic fatigue tests revealed that cyclic softening and hardening strongly depend on the applied strain amplitude. Besides, prismatic < a > slip was the primary cyclic deformation mode when the value of plastic strain amplitude less than that of elastic strain amplitude, otherwise prismatic < a > slip and {1012} <1011 > twinning dominated the deformation. Due to the combination effect of grain rotation, dislocation accumulation and twinning, cyclic softening, saturation and hardening behaviors were presented in Zircaloy-4 alloy.