Deformation and Damage Evolution of the Microstructure around Ti-Particles in IF Steel during Tensile Deformation

Abstract

The microstructure evolution in the deformation zone around second phase particles of IF steel sheets subjected to tensile deformation has been investigated in order to correlate it to the damage at microstructural scale. The experimental set-up consisted of a series of interrupted tensile tests which were carried out at different tensile deformations up to fracture. The microstructure of the deformed samples was investigated by EBSD analysis in which the EBSD scans were focused on the areas containing Ti (C, N) particles of cubical shape. It was found that at tensile strains below 25%, the ferrite matrix exhibited the evolution of slip bands inside specific grains depending on their crystallographic orientation although no special strain localization around the particles was observed. After 35% of tensile strain, the strain concentrates around the particles and particle-matrix decohesion was observed. The lattice rotations of the matrix surrounding the particles as well as the selective deformation of the grains are analyzed and discussed.

Viscoplastic regularization of local damage models: revisited

“…This pathological mesh dependent phenomenon is purely numerical and does not have any physical significance. In reality, damage consists of voids [17,30] and/or cracks [28]. Therefore, physically, damage can not continue to grow at a local material point.…”