A constitutive model for the uniaxial tensile plastic behavior of metals based on the instantaneous strain-hardening exponent

Abstract

The present work develops a new constitutive equation model for strain-hardening behavior of metallic materials (named herein as the Gonoring model) based on the definition of the instantaneous strain-hardening exponent. This new proposal was applied to experimental uniaxial tensile data of a lean duplex stainless steel alloy UNS s32304 (LDSS 2304) in the as-received (AR) condition and on identical heat-treated specimens at four different temperatures. This choice was justified because this is a steel that presents two phases (ferrite and austenite), which makes it a more universal example from the point of view of applying a new constitutive equation model. These heat treatments induced sigmoidal strain-hardening behavior at uniaxial tensile in this alloy. The Gonoring proposal was able to predict the strain-hardening behavior of both the sigmoidal and parabolic-shaped strain-hardening curve of a lean duplex stainless steel alloy 2304.

Keywords

• Constitutive equation
• Strain hardening behavior
• Instantaneous strain hardening exponent
• Duplex stainless steel
• Heat treatments