Tensile properties and flow behavior analysis of modified 9Cr-1Mo steel clad tube material

The tensile properties and flow behavior of modified 9Cr-1Mo steel clad tube have been investigated in the framework of various constitutive equations for a wide range of temperatures (300-923 K) and strain rates (3 x 10(-3) s(-1),3 x 10(-4) s(-1) and 3 x 10(-5) s-1). The tensile flow behavior of modified 9Cr-1Mo steel clad tube was most accurately described by Voce equation. The variation of instantaneous work hardening rate (theta = d sigma/d epsilon) and sigma theta with stress (sigma) indicated two stage behavior characterized by rapid decrease at low stresses (transient stage) followed by a gradual decrease in high stresses (Stage III). The variation of work hardening parameters and work hardening rate in terms of theta vs. sigma and sigma theta vs. sigma with temperature exhibited three distinct regimes. Rapid decrease in flow stress and work hardening parameters and rapid shift of theta vs. sigma and sigma theta vs. sigma towards low stresses with increase in temperature indicated dynamic recovery at high temperatures. Tensile properties of the material have been best predicted from Voce equation. (C) 2014 Elsevier B.V. All rights reserved.