Effects of annealing temperature on stress corrosion susceptibility of AA5083-H15 alloys

Effects of annealing temperature on stress corrosion susceptibility of AA5083-H15 alloys were studied by annealing specimens at 150, 200, 250, 300, and 350 °C before sensitization. Nitric acid mass loss testing and slow strain rate testing were conducted to investigate intergranular corrosion (IGC) and stress corrosion cracking (SCC). Results indicate that H15 alloy was less susceptible to IGC, but this alloy had the highest susceptibility to IGC and SCC after sensitization. Due to the continuous precipitation of β phase, the sensitized 150 and 200 °C alloys were highly susceptible to IGC and SCC. The 250 °C alloy was less susceptible to IGC because of the absence of the precipitation of β phase. After sensitization, this alloy was also less susceptible to IGC and SCC on account of the discontinuous precipitation of β phase. The sensitized 300 and 350 °C alloys were susceptible to IGC but less susceptible to SCC because of their lower strength and higher elongation.