The effect of a deformation banding criterion on simulated b.c.c. rolling textures

Deformation Banding ( DB ) in cold rolled mild steel has been experimentally established by microstructure investigation and mis-orientation analysis using EBSP. Clearly this deformation banding mode must be included in modelling the deformation texture, and this has been attempted. The cause of deformation banding in all DB models is the reduction of the total work for plastic deformation through a relaxation of the deformation constraints. In the first DB model, all grains are assumed to band from the first deformation step. Such an unrealistic assumption has been eliminated in the new model by the introduction of a banding criterion which states that deformation will occur only if the energy for normal slip involved in the DB model is less than that for the RC model. The computer grains firstly deform according to conventional RC model before the DB criterion is satisfied and then deform according to DB model after the criterion is met at a specific step. If the ratio of critical resolved shear stresses for {110} and {112} slip planes is set at unity, the model overpopulates {111} component, but when the ratio is set at 0.85:1.0, the resulting ODF is closer to the measured textures.