EBSD in a soft steel Characterisation of transgranular crack propagation by

This study is concerned with crack propagation in a soft steel sheet during drawing. The drawability is considered in relation with the structural anisotropy. Most existing studies on crack propagation are based on the global mechanical properties. However, microstructural inhomogeneity can lead to micro-crack formation. Micro-texture can affect crack propagation and stops in soft steel during drawing. The EBSD technique is used to show that the adjustment of the grain orientation from the initial recrystallization component {111} towards the deformation orientation {111} incites a trans-granular crack inside a {111} grain in a globally ductile material. Industrial metals always undergo various external stresses during fabrication and under service conditions. When they possess a heterogeneous microstructure, the usual mechanical properties do not allow accurately determining the risks of cracking that often occurs throughout manufacturing and service. In the plastic deformation studies, the microstructure is a basic factor of predicting the mechanical material behaviour. The presence of microstructural inhomogeneities will certainly affect the agreement between predictions based on homogeneous deformation and the experimental often required in safety analysis to consider that a crack might be initiated and lead to its propagation. It is important to know whether or not the material will be able to stop the crack before it goes through the entire structure, during its response to the external stresses. To answer this question, it is essential localization is a result of both the external solicitation (loading, piece geometry) and the microstructure properties. It is this duality that makes the success of the micro-macro approaches which are based on changes of dimension scales. Therefore, such approaches allow a more comprehensive study, closer to the material behaviour during use. The global behaviour of industrial metals is essentially controlled by the local micro-stress concentrations. Strain localization that appears may locally lead to a strong decrease of the ductility and therefore to a material rupture. The EBSD technique (Electron Back Scattering Diffraction) allows the correlation between the microstructure characteristics and the distribution of plastic deformation and stresses EBSD is presently used predominantly in nearly all metallurgy research approaches and has become a common technique used in the characterization of polycrystalline materials the method has become increasingly useful in the analysis of grain size and distribution, grain boundary disorientations and texture analysis of materials. The EBSD technique makes it possible to