Mechanism of crack propagation in low cycle fatigue of type 316L stainless steel within the temperature range 20–300 °C

Abstract

Strain-controlled low cycle fatigue tests on type 316L austenitic stainless steel using uniaxial specimens have been conducted in the temperature range 20–300 °C. A fixed strain rate of 1 × 10 −3 s −1 and a total strain range varying between 0.4 and 1% were employed. A major finding is that there is a trough in the total fatigue life vs. temperature curve at high strain ranges and at temperatures in the region of 50 °C, caused by cyclic cold creep. In this paper, we examine the microstructural characteristics of the region below the fracture surface during low cycle fatigue and propose a model which semiquantitatively explains the anomalous low cycle fatigue behaviour at 50 °C.