Effect of the tension hold time on Low Cycle Fatigue behavior of AISI 304L stainless steel at 600℃ was investigated in Ar atmosphere under the axial strain control at a strain rate of $6×10^{-4}S^{-1}$. Under the triangular continuous cycling, fracture was occured by the transgranular propagation of fatigue crack initiated at the specimen surface.
In the fatigue test with 5 min. hold time at the peak tensile strain, fatigue crack propagated by transgranular mode only and the grain boundary creep cavities was not observed more over, critical fatigue life was as same as that of continuous cycle.
Critical fatigue life was decreased and cavities at the grain boundary surfaces was observed under the fatigue test with 10 min. hold time.
This phenomena was supposed to be attributed to the amount and distribution of grain boundary carbides and inclusions of AISI 304L stainless steel which acts as the nucleation sites of cavities.
As a results of the SEM observation of the fractured surfaces of specimens and the critical fatigue life calculated from the fatigue crack growth rate. It was believed that the critical fatigue life is that associated with phase I type growth proposed by Wareing.
