Abstract
In this paper, tensile behavior and low cycle fatigue behavior of 316L stainless steel were investigated. This material is currently favored structural material for several high temperature components such as the liquid metal cooled fast breeder reactor (LMFBR). Research was performed at 550℃, 600℃ and 650℃ since working temperature of 316L stainless steel in a real field is from 400℃ to 650℃. From tensile tests performed by strain control with 1×10^<-3> /s, 1×10^<-4> /s and 1×10<-5> /s strain rates at each temperature, negative strain rate response (that is, strain hardening decreases as strain rate increases) and negative temperature response were observed. Strain rate effect was relatively small compared with temperature effect. LCF tests with constant total strain amplitude were performed by strain control with a high temperature extensometer at RT, 550℃, 600℃, 650℃ and total strain amplitudes of 0.3%〜0.8% were used and test strain rates were 1×10<-2> /s, 1×10<-3> /s and 1×10<-4> /s. A new energy based LCF life prediction model which can explain the effects of temperature, strain amplitude and strain rate on fatigue life was proposed and its validity was verified by analyzing the test results and comparing with currently used models.
