Effects of stabilization treatment on the precipitation behavior of β phase and stress corrosion for AA5383-H15 alloys

This article mainly focuses on stabilization treatments that influence stress corrosion resistance of an AA5383-H15 alloy after undergoing sensitization treatment at 100 °C/168 h. The results show that without stabilization of the sensitized AA5383-H15 alloy, the β precipitates are distributed continuously like a mesh at grain boundary, and this is the main cause of intergranular corrosion failure. However, applying 3 different stabilization treatments (220 °C/3 h, 250 °C/3 h, and 280 °C/3 h) to the AA5383-H15 alloy shows a dramatic decrease in the β phase precipitation routes along the grain boundaries after the sensitization treatment, and thus an effective improvement in the corrosion resistance performance of AA5383-H15 alloys. Of all the stabilization treatments, the application of 250 °C/3 h stabilization treatment is found to be most effective. Applying 250 °C/3 h stabilization treatment facilitated partial recrystallization of the matrix, leading to suppress the continuous precipitation of the β phase along the grain boundaries during sensitization but instead precipitate in discontinuous mesh-like distribution, which can decrease its sensitivity to stress corrosion.