Prediction of Deformation Behavior of Steel Sheets Based on Crystallographic Texture

Stress-strain curves under various multiaxial stress states and yield loci of steel sheets were calculated using measured texture data and a crystallographical theory. A textured polycrystalline sheet is simplified to be an aggregate of many single crystals with various orientations. A Crystallite Orientation Distribution Function (CODF) which was calculated from measured texture data was used as a volume fraction of a certain oriented crystal. Considering restricted glide on slip systems as a deformation mode of a single crystal, a strain tensor in each crystal subjected to various multiaxial stress states was calculated. In order to calculate a strain tensor for a textured polycrystalline sheet, the calculated strain for each single crystal was weighted by the CODF and averaged over all orientations. The calculated results are compared with experimental ones for two low carbon steel sheets. The behavior of strain-hardening and a planar anisotropy of the calculated stress-strain relation are in good agreement with the experiment. The calculated yield locus can also represent a general shape of the measured one.