The microstructure, crystallography, and mechanical response of a commercial super-austenitic stainless steel, AL-6XN, has been investigated. Three-dimensional (3D) reconstructions, generated by combining serial sectioning techniques with Electron Backscatter Diffraction (EBSD), are used for characterization of the microstructure and crystallography of the material, and as input for 3D Image-Based Finite Element Models (IB-FEM). Using these techniques, the distributions of crystallographic 3D grain boundary normals have been quantified, and are shown to provide critical new information not previously attainable from the commonly used morphological descriptors. Image-based finite element simulations, with the 3D microstructure and crystallography as input, were performed to determine the critical microstructural features at which failure is likely to initiate.