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The work-hardening of three common automotive low carbon steel sheets is described in terms of two different types of microstructure based models. The first model employed is the classical Kocks-Mecking model. On the other hand, the second model incorporates the effect of the density evolution of non-redundant dislocations, also known as Geometrically Necessary Dislocations (GND), into the Kocks-Mecking hardening law. Each of both models was coupled to a Taylor-type crystal plasticity framework in order to follow the dislocation density evolution over all slip systems. One of the microstructural parameters employed on the calibration of the second model is the density of GND, parameter which was experimentally acquired from crystal orientation maps by EBSD (Electron Backscatter Diffraction) on the tensile samples.

The mechanical anisotropy of low carbon steel sheets, usually characterized by the Lankford parameter, is strongly correlated to the crystallographic texture and its evolution during deformation. In this study, a homogenization model based on crystal plasticity was employed to simulate the evolution of the Lankford parameter during tensile deformation of three different steel alloys commonly used in the automotive industry. The crystallographic texture, together with other material parameters, is used as an input for the model, whereas the calibration procedure is only carried out on the experimental tensile test data of the samples aligned along the rolling direction of the sheet. The validation of the model is then performed on the experimental data of tensile samples oriented along 45° and 90° with respect to the rolling direction of the sheet.