Accurate Modelling of Flow Stress of AISI1025 at Room Temperature and Its Application to Precision Forging Simulation

Abstract

This paper evaluates and criticizes the Swift model of expressing strain hardening behaviours of metals at room temperature using an experimental tensile test and its FE prediction. A concept of reference flow stress curve composed of two ranges of strain divided by the true strain at the necking point is proposed, which predicts tensile test exactly from the standpoint of engineering and is thus employed to evaluate the Swift model. It has been shown that it has a weak point in describing the flow stress of typical strain hardening material with emphasis on necking. An improved Swift model is applied to obtain accurate flow stress of a commercial steel AISI1025 and it is employed to simulate a sequence of cold forging processes by precision complete analysis for process and die optimal design in terms of die life, which should be conducted under an accurate analysis model. ? 2021, The Minerals, Metals & Materials Society.