Keywords : Residual stress
Experimental and Simulation Study the Effect of Different Reduction Ratios in Cold Rolling Process on the Residual Stresses of AL 2024 Alloy
Engineering and Technology Journal,
2015, Volume 33, Issue 5, Pages 1049-1064
Cold forming processes are the common processes in sheet metal forming, especially in the final stages of production processes. In this work, cold rolling process was selected to study the effect of different reduction ratios on the residual stresses state in aluminum alloy (2024). Sheets of aluminum alloy (2024-T3) were prepared with dimensions (400 X 80 X 3.15 mm).The annealing process was conducted for these sheets to get the temper condition (2024-O). The cold rolling process was performed with different reduction ratios (10%, 20%, 30%, 40%, 50%, 60%) by a rolling machine composed of two rolls having (50 mm) diameter each.The residual stresses were measured using X-ray diffraction technique (XRD) in two directions (rolling direction RD, and transverse direction TD).The results of X-ray diffraction showed the presence of residual stresses at the surface of rolled specimens, and these were compressive stresses in the two tested directions (RD, and TD) at 10% reduction ratio. When the reduction ratio exceeded 10%, these stresses transformed to tensile stresses for specimens tested in rolling direction, while these stresses remained compressive type for all reduction ratios in transverse direction.Computer simulation was carried out using finite element method (FEM) by (ANSYS-LSDYNA 12.1) software to investigate the residual stresses behavior of AA 2024. The numerical results showed a good agreement with the experimental resultsespecially for samples tested in the rolling direction.