Abstract: Based on the time-dependent strain cyclic characteristics and fatigue behaviors of SS304 stainless steel under multi-axial cyclic loading at 700℃, and in the frame of unified visoco-plastic cyclic constitutive model and continuum damage mechanics theory, the damage-coupled multi-axial time-dependent constitutive model and fatigue failure model were proposed. In the model, the evolution equation of damage was introduced in and the time-dependent effects, e.g. holding time, loading rate, were taken into account. The model was applied to the simulation of whole-life cyclic deformation behaviors and prediction of LCF life for SS304 stainless steel in multi-axial time-dependent low cycle fatigue tests. It is shown that the simulated results agree well with experimental ones.

Key words: SS304 stainless steel, Constitutive model, Low cycle fatigue, Failure model, Damage-coupled, High temperature