The Influence of Initial Microstructure on the Recrystallization Behaviour of Cold-Rolled AA3003

Abstract

Due to an excellent combination of strength, formability, corrosion resistance and material cost, extruded Al-Mn alloys (e. g. AA3003) are widely used in heat exchanger applications for automotive and off road applications. Grain size control is essential, as it affects important properties such as corrosion resistance, strength and formability. The present work describes experimental observations on the microstructure resulting from different homogenization practices of AA3003 which modify the dispersoid distribution and the initial grain size. This work considers deformation by cold rolling to reductions of 10-80 pct followed by annealing at the temperature range of 350 to 600 degrees C. Preliminary results show that there is a critical temperature below which concurrent precipitation of Mn-bearing dispersoids retards recovery and static recrystallization giving rise to different recrystallized grain sizes. The effect of initial grain size was observed to be significant when there were almost no dispersoids with cold reductions of 10-20 pct.