Temperature-Dependent SRS Behavior of 316L and Its Constitutive Model

The strain rate sensitivity (SRS) and temperature sensitivity (TS) of 316L austenitic stainless steel were investigated by constant strain rate test (CSRT) and strain rate jump test (SRJT) under four temperatures (293, 373, 473 and 573 K) and four strain rates (5 x 10(-4)/s, 1 x 10(-3)/s, 5 x 10(-3)/s and 1 x 10(-2)/s). The results show that temperature sensitivity (TS) indexes at different strain rates are coincidence to be negative, related to temperature softening. On the contrary, SRS indexes change from positive to negative with the increase in temperature associated with dynamic strain aging (DSA). Moreover, based on the comparison between CSRT and SRJT, SRS and TS indexes obtained by two methods agree well. It proves that the SRJT can describe the SRS and TS phenomenon of 316L efficiently. Furthermore, the effects of temperature and strain rate on fracture mechanism were discussed. At last, an improved Johnson-Cook model was proposed to consider the temperature-dependent SRS behavior of 316L.