The effect of oscillating capping TIG welding on residual stresses of 2219-T8 butt joint

Oscillating capping TIG welding (OCW) was proved valid to increase joint properties of the 2219-T8 aluminium alloy. Its effects on the welding residual stresses (WRS) should also be clarified. In this study, the residual stresses of the 2219-T8 plate butt welding of capping welding (CW) + OCW and CW technologies were investigated by simulation and experiment. The results showed that OCW reduced the peak value of the tensile longitudinal residual stress (LRS) in the joints. And its mechanism was discussed. Differences in bead geometry, heat input and number of welding passes of OCW affected LRS. Among them, wide bead geometry resulted in lower residual plastic strain, thus decreasing LRS peak value in a great manner.