Compressive Flow Stress-strain Behavior of Duplex Stainless Steels

Abstract

The compressive flow stress-strain behavior of duplex stainless steels composed of austenite and ferrite with various volume fractions is studied by static upsetting tests to the extent of large strain in the temperature range of cold working, from 30 to 350°C. The flow stress of duplex stainless steels deformed to large strain at the temperature less than 200°C are higher than that estimated by the law of mixture. This difference is due to prior deformation of the softer austenite phase and its rapid work-hardenig in this temperature range. It is confirmed by a numerical analysis making use of rigid-plastic finite element method ( FEM). As a result of present investigation, the flow stress model of duplex stainless steels is proposed and compared with the experimental data.