The influence of room temperature storage on intergranular corrosion susceptibility of AA6082 Al-Mg-Si alloy

• Room temperature storage results in Mg segregation and β’ phase precipitation at HAGB in AA6082-T4 alloy. • Room temperature storage of the alloy results in an increased susceptibility to IGC. • The naturally aged T4 alloy shows IGC susceptibility higher than that in T6 condition. • IGC occurs preferentially at high angle grain boundaries in the alloy in both T4 and T6 conditions. The influence of room temperature (RT) storage on the microstructure and intergranular corrosion (IGC) behaviour of AA6082-T4 alloy is investigated by the combination of electron microscopy, electrochemical measurement and immersion testing. After 10 months storage at RT, precipitation of β ’ phase and segregation of Mg had occurred at high angle grain boundaries (HAGBs) in the alloy that was in T4 condition, leading to an increased IGC susceptibility, which is even higher than that for the alloy in T6 condition.