Assessment of simple flow-stress relationships using literature data for a range of steels

Abstract

A variety of materials are processed using hot deformation, and simulation of these processes needs information on the flow stress as influenced by theprocess parameters. An explicit representation is ideal, for use with the ever growing application of the finite-element analysis, for simulation. A vast amount of experimental flow-stress data is now available in the literature for a range of steels including plain-carbon steels, low-alloy steels, HSLA steels and stainless steels tested in either compression, tension or torsion using solid, tubular or reduced-gauge-length specimens. In the hot-deformation range, the flow curves typically exhibit dynamic recovery, dynamic recrystallization or a combination of both, depending on the processing conditions of strain rate and temperature. In this paper, flow-stress data for several materials have been analysed and it has been found that they can be adequately represented using a hyperbolic-sine relationship. The flow-stress relationships that were tested included strain in an explicit way, and proved to be very successfullfor all of the materials considered, irrespective of the material, the test conditions and the basic flow response.