The Effects of Cold Rolling and Stabilization Treatment on the Improvement of Microstructure, Mechanical Properties, and Corrosion Behavior of AA5083 Sheet

In this study, the effect of time and heating rate was investigated on stabilization of AA5083 aluminum sheets with a thickness of 2.5 mm using cold rolling and heat treatment. For this purpose, the initial plate with a thickness of 10 mm was subjected to homogenization treatment at 520 degrees C for 12 h and the microstructure and mechanical properties were studied. Then, the plate was rolled to a thickness of 4 mm, and recrystallization annealing was performed between each stage of rolling at 330 degrees C for 30 min. Finally, during the H34 thermo-mechanical treatment, 35% reduction was performed in thickness, and stabilization treatments were applied at 220 degrees C for 15 min, 1, and 4 h in an electrical resistance and an infrared furnace. It was observed that by using appropriate heating rate and stabilizing time, in addition to improving the mechanical properties and achieving fine-grained structure, the corrosion resistance of the alloy is also suitable. The yield and tensile strength were increased in the final sample by 91 and 27%, respectively. Microstructure was studied using optical and scanning electron microscopy. It revealed fine-grained structure after the process. The grain size was reduced by 37 and 27% for the stabilized samples compared to as-received sample in the infrared and resistance furnaces, respectively. Potentiodynamic polarization and electrochemical impedance spectroscopy tests showed that the sample stabilized at higher heating rate had the best corrosion resistance. The corrosion current density was reduced by 92% compared to the base alloy.