On the Influences of Pre-deformation on Fatigue Behavior of SS۳۱۶ Stainless Steel

In this study, the influences of pre-deformation onfatigue behavior were investigated experimentally underuniaxial cyclic loading for SS۳۱۶ stainless steel at roomtemperature. Regarding to pre-deformation, thespecimens were conducted to uniaxial cyclic stressingwith non-zero mean stress and applied stress larger thanyield stress. Therefore, the pre-deformation would be inform of cyclic accumulation of inelastic strain or theterm “ratcheting”. Finally, the same specimens wereconducted to fatigue test in order to investigate theeffects of various pre-deformation on fatigue behavior ofthe specimens. The amount of accumulated inelasticstrain and the pre-deformation loading have significanteffects on the subsequent fatigue behavior of SS۳۱۶stainless steel. The cyclic pre-deformation caused anincrease in the subsequent fatigue life in comparisonwith the test without pre-deformation (pure fatigue). Thisbehavior is due to overloading phenomenon which takesplace in two stages tests and certain loading conditions.Regardless of the accumulated ratcheting strain, thefatigue life increased with increasing pre-deformationstress amplitude and stress ratio and decreases withincreasing the pre-deformation mean stress.

کلیدواژه ها:

Pre-deformation ، Fatigue ، SS۳۱۶stainless steel ، Uniaxial cyclic loading.