MODELING OF THE HEAT AFFECTED ZONE OF ALUMINUM ARC WELDS.

An arc welding heat transfer model, based on finite differencing techniques, was used in conjunction with kinetic relationships developed to represent precipitation during welding of 6009. These kinetic relationships were based on the additive characteristic of the precipitation reaction. The extent of the reaction, through loss in hardness, was then determined for the various thermal profiles in the heat affected zone. These produced hardness profiles that varied depending on the welding heat input. Welding experiments were conducted to compare measured heat affected zone hardness profiles to those predicted under identical conditions.