EURODYMAT 2006 - 8th International Conference on Mehanical and Physical Behaviour of Materials under Dynamic Loading
J. Cirne, R. Dormeval, et al.
J. Phys. IV France 134 (2006) 75-80
DOI: 10.1051/jp4:2006134013

Experimental investigations and modelling of strain rate and temperature effects on the flow behaviour of 1045 steel

L.W. Meyer¹, T. Halle¹, N. Herzig¹, L. Krüger² and S.V. Razorenov<sup>3

1</sup>  Chemnitz University of Technology, Materials and Impact Engineering, 09107 Chemnitz, Germany
²  Technische Universität Bergakademie Freiberg, Institut für Werkstofftechnik, Gustav-Zeuner-Straße 5, 09599 Freiberg, Germany
³  High Energy Density Research Center, IVTAN, Izhorskaya 13/19, Moscow 127412, Russia

Published online: 26 July 2006

Abstract
If structures have to be designed to sustain low and high loading rates, the appropriate constitutive equations are essential for the accurate modelling of the structural response. However, a lack of the required data is observed very often, especially, if a very wide range of strain rates has to be covered. Therefore, the flow behaviour of the steel 1045 (C45E) was investigated with defined chemical composition and microstructure in a very wide range of strain rates between 10^-4 and 10⁵ 1/s and different temperatures. The rate-dependent thermomechanical behaviour was determined using low strain rate (10^-4 to 10⁰ 1/s) servo-hydraulic compression testing, high strain rate (~10² 1/s and 10³ 1/s) compression drop weight testing and split Hopkinson pressure bar testing, and for very high strain rates (10⁵ 1/s) the plate-impact test. Additionally, strain rate jump tests at relatively low strain rates and different temperatures were performed to determine the activation volume at constant temperature and deformation. The measured flow stresses as well as the strain and strain rate hardening behaviour as a function of strain rate and test temperature are discussed in terms of the microstructural deformation processes. The theory of thermally activated flow is applied and compared to the widely used models like the Johnson-Cook model and a dislocation drag model. The occurrence of possible dislocation drag effects is discussed in conjunction with the measured data. Our results show, that the strain rate dependence of the flow stress of 1045 steel can be described completely by the theory of thermal activation up to strain rates of 10⁵ 1/s.

© EDP Sciences 2006