The deformation textures of B.C.C. polycrystals (uniaxial tension, rolling) and the Lankford coefficient are predicted using the Taylor model and a nonhomogeneous model. The mixed glide conditions {110}〈111〉 + {112}〈111〉 are imposed using the yield polyhedron proposed by Orlans-Jolietet al. [1988]. The nonhomogeneous model is based on the Arminjon model [1987]; however, Arminjon used the pencil glide condition. An original calculation is proposed to simulate with a high precision deformation textures (orientation distribution functions O.D.F. F′(g)), without using the harmonic method, which leads to truncation errors. No restrictions are imposed on the eventual symmetry of the initial O.D.F. F(g). Using experimental and calculated textures of low carbon steels, it is shown that the homogeneous Taylor model gives good results for low deformations (uniaxial tension), whereas the nonhomogeneous model improves the Taylor model for high deformations (rolling).
This contribution complete a previous one (1) in that the specific problems of the elastoplastic behaviour of body-centered polycrystals are analyzed. The experimental results (yield stress, Lankford′s ratio, textures, …) are compared with those of self-consistent and Taylor modelling codes. A particular attention is put on the influence of the selection of glide systems in the framework of crystallographic or non-crystallographic assumptions.