Recovery of tensile properties of AA5182 after cold rolling

An experimental AA5182 sheet was cold rolled 80%, and tensile specimens removed with orientations 0, 45 and 90 degrees to the rolling direction. Room temperature monotonic tensile tests were performed on the specimens in different recovered states obtained by isothermal annealing at 230 degrees C from 0.1 to 10h. The tests were instrumented to measure instantaneous plastic strain ratio, and unloaded just after incipient necking, but before failure if possible. With annealing the flow curves are characterized by lower strains to the onset of jerky flow, the reappearance of yield point elongation, decrease in work hardening, and increasing ductility. The recovery in substructure was described using a constitutive parameter proportional to the mean slip distance.