Creep-Fatigue Properties of 316LC Thin-Walled Tubular Specimens Under the Conditions of Push-Pull Loading and Cyclic Pure Torsion

Abstract

Fully reversed creep-fatigue tests were conducted on 316LC austenitic stainless steel thin-walled tubular specimens at 1023K in air. Strain waveforms adopted were so called PP, CP and CC type ones. Thin-walled tubular specimens were tested under two kinds of loading conditions, that is, cyclic axial push-pull loading and cyclic torsion. Outer diameter, wall thickness and gage length of the tubular specimen are 22mm, 1mm and 25mm, respectively. As the results, the effect of stress state on the partitioned inelastic strainrange versus life relations was determined based on the tubular specimen data under both cyclic axial push-pull loading and cyclic torsion. It is shown that the effect of stress state on Δε_<cp>-N<cp> and Δε_<cc>-N_<cc> relations as well as on Δε_<pp>-N_<pp> relation can be quantified by using the multiaxiality factor.