Met. Mater. Int., Vol. 19, No. 5 (2013), pp. 1005~1019
doi: 10.1007/s12540-013-5013-3
Mechanical Modeling of Macroscopic Behavior for Anisotropic
and Heterogeneous Metal Alloys
O. Chahaoui
1,2
, M. L. Fares
2,
*
, D. Piot
3
, and F. Montheillet
3
1
Laghrour Abbes University, Sciences and Technology Institute, 40000, Khenchela, Algeria
2
Badji-Mokhtar University, Mechanics of Materials and Plant Maintenance Laboratory (LR3MI),
P.O. Box 12, 42000, Annaba, Algeria
3
Centre SMS, CNRS UMR 5307, Ecole Nationale Superieure des Mines,
158 Cours Fauriel, 42023, Saint Etienne, France
(received date: 27 December 2012 / accepted date: 28 January 2013)
The present investigative work was focused on modeling the effect of through-thickness texture gradients
on the global mechanical behavior of a rolled ferritic stainless steel sheet. The material was experimentally
characterized according to the needs of the analysis. First, a homogeneous rolled sheet was analytically described,
based on Hill's formalism of generalized materials. Then, a heterogeneous sheet was analyzed through two ana-
lytic approaches. The predictive capability of the resulting approaches was also proven in relation to the choice of
the pseudo-anisotropic coefficients selected from fictitious materials. Finally, the application of a simple method,
called continuum mechanics of textured polycrystals, taking into account crystallographic considerations, was
adopted. As a result, this method was found to be an effective way to model the mechanical behavior of an aniso-
tropic and heterogeneous sheet, replicating the evolution of experimental yield stress and plastic strain ratio either
in terms of evolution or in those of level values. An attempt to estimate the impact of low-texture gradi-
ents on the heterogeneity of any industrial metal sheet is also made.
Key words: hot working, plasticity, texture, rolling, tensile test
1. INTRODUCTION
Ferritic stainless sheets steels (FSS) are usually produced
by hot and cold rolling processes, followed by annealing treat-
ment. Thermal factors (e.g. temperature gradients across the
sheet resulting from the hot rolling) and boundary conditions
(e.g. friction between rollers and the metal sheet during cold
rolling) act together to cause significant deformation hetero-
geneities in sheet thickness. These processes form texture
gradients that have the ability to affect the formability and
drawability of the metal sheet, in this instance the final
mechanical properties [1]. It is well established that if these
texture gradients are not fully eliminated or modified by the
subsequent annealing treatment, the final product will be
prone to defects, such as thinning, earring and ridging [2-5].
Appropriate control of these defects lies in the optimization of
the material formability through two possible alternatives.
The first is to conduct specific and complex experimental
investigations by monitoring the process conditions that
cause disruptions in the production cycle, which are costly for
manufacturers. A second option is to perform apposite mod-
eling and simulation procedures that can be promising sub-
stitutes to provide qualitative and quantitative outcomes,
thus contributing to a better prediction of the mechanical
sheet behavior at a lower cost. For this purpose, several alter-
native and versatile numerical/analytical models have been
proposed (see [6] and the references therein). Most of them,
essentially based on Hill's yield criterion [7,8], include either
phenomenological or physical considerations, and are intended
to describe in a more or less comprehensive way, the stress-
strain response of the anisotropic rolled sheet on both micro-
scopic and macroscopic scales. In many examined cases,
Taylor assumptions (homogenization technique), wherein it
is assumed that grains experience the same strain as the
imposed macroscopic one, are adopted to achieve the micro-
to-macro transition [9]. Corresponding findings were mostly
focused on numerical considerations (e.g. finite-element models
[10]), and only a limited number of them were related to
physical considerations, such as crystallographic texture.
This paper is a complement of an earlier work [11] and
describes the main stages of modeling, via analytical approaches,
the effect of through-thickness texture gradients on the global
mechanical behavior of a rolled and annealed FSS industrial sheet.
*Corresponding author: fares.lamine@univ-annaba.org
©KIM and Springer, Published 10 September 2013