Welding deformation controlling of aluminum-alloy thin plate by two-direction pre-stress method

The two-direction pre-stress method was proposed to control welding deformation as well as hot cracking, and it was applied to 2024Al aluminum alloys. The new method can decrease the tendency of hot cracking caused by the conventional single pre-tension during welding, especially at the starting position of the weld. In tests, the contribution supplied by transverse pre-stress for controlling welding deflection deformation was found, except for preventing cracking. The maximum residual stress was calculated by finite element simulation method under the condition of welding without pre-stress and welding with two-direction pre-stress. The results showed that the deflection deformation of weldments gradually decreased with the increasing of pre-stress value. For given pre-stress value of 0, 0.5σs, 0.7σs in longitudinal direction and 0.7σs (longitudinal) + 0.15σs (transverse), the maximum deflections were 13 mm, 9 mm, 5 mm, 1.5 mm, respectively.