Flow behavior and deformation of Nb micro-alloyed steel during strip hot rolling

¹ School of Materials and Metallurgy, Northeastern University, Shenyang 110819, P.R. China
e-mail: hugkj-545@163.com
² National Engineering and Research Center for Continuous Casting Technology, Center Iron and Steel Institute, Beijing 100081, P.R. China

Received: 21 April 2015
Accepted: 14 September 2015

Abstract

In this paper, the material parameters of the Johnson Cook material model were determined and analyzed. Then, the flow curves were obtained by thermal simulation machine during the hot compression deformation process. The experimental data over a wide range of temperatures (1173 K–1373 K), strain (0.1–0.5) and strain rates (0.001–10 s^-1) were employed to evaluate the material constants of Johnson Cook constitutive models. The flow stress predicted by the Johnson Cook equation was the same as the experimental result. Afterward, the new verification testing and 3D finite element compression model was established, which showed the reliability of the constitutive equation. The finite element simulation results show that the calculated deformed shape and the compressive stress-strain curves of the specimens were consistent with the experiment. The effectiveness and feasibility of the constitutive equations in the finite element calculations were proved. The equation supplied a flow stress model for rolling simulation calculation. Then, the 3-pass vertical-horizontal hot rolling model was established by Abaqus/Explicit. The simulation results agree with the measured values of the hot strip rolling.