Optimizing Cold Compression Deformation to Remove Residual Stresses in Die Forged Disc of Al-Mg-Si Alloy

Abstract

Quenching residual stresses in Al-Mg-Si alloy forged disc were balanced via cold deformation compression method. In this experiment firstly, the forged disc of Φ210x52 mm was prepared from extruded stock material of Φ160x90 mm through close die forging technique. Next, the forged discs were quenched in water and cold compressed immediately. Finally, the discs were artificial aged to finish in T652 temper. Close die forging and cold compression deformation was performed on a 1200 Ton hydraulic forging press. The amount of cold compression deformation was varied from 2.0 to 5.0% to gauge the optimum level of cold compression for the removal of quenching residual stresses. The residual stresses were measured in terms of dimensional stability of the machined component. Results showed that the 3.8% cold compression deformation was the optimized value for the work piece geometry under investigation. Further, the effect of cold (room temperature) and hot water (~60°C) quenching on the residual stresses was also studied and compared with that of cold compression method.