1.1 This International Standard specifies the methods of integranular corrosion testing for solution heat-treatable aluminium alloys without protective coatings. The sensitivity of solution heat-treatable aluminium alloys to intergranular corrosion is a function of the alloy chemical composition, method of manufacturing, solution heat treatment, quench treatment and artificial precipitation hardening (ageing) treatment. In the naturally aged condition, the sensitivity of solution heat-treatable aluminium alloys to intergranular corrosion is a function primarily of the rate of cooling during quenching over a critical temperature range. 1.2 This International Standard is applicable to cast and wrought heat-treatable aluminium alloys in the form of castings, forgings, plates, sheets, extrusions and semi-finished or finished parts, in order to carry out comparative assessment of alloys of different grades and thickness depending on their chemical composition and other factors, and also to check the thermal processing quality of the tested materials. The test results provide information to determine the intergranular corrosion resistance and thermal processing quality of the tested materials. 1.3 The test results cannot be regarded as absolute, because they are not applicable to all environments that can be met in service. They are best used in a relative manner, to compare the intergranular corrosion resistance of various heats of solution heat-treatable aluminium alloys.