Visco-plastic constitutive models of steel at high temperature

Two constitutive elasto-visco-plastic models are adopted to simulate the be havior of plain carbon steel at high temperature, specifically at the auste nitic range (950-1300 degrees C), being particularly appropriate for the nu merical simulation of casting and hot-working processes. The response in ha rdening, creep and non-uniform loading conditions is analyzed and compared with experimental data. An efficient numerical integration scheme is propos ed and its accuracy is evaluated using iso-error maps. The consistent isoth ermal tangent matrix is computed and the final models are implemented into an FEM code. Several tests are performed to evaluate the accuracy and robus tness of the integration scheme. Finally an application concerning the anal ysis of the thermal stresses produced at the early stage of a steel continu ous casting process is shown. (C) 2000 Elsevier Science S.A. All rights res erved.