Abstract: A new method named welding with trailing rotating extrusion (WTRE) is proposed to control residual stresses and distortion of thin-plate weldments. Its mechanism of controlling welding deformation is based on reducing the longitudinal residual tensile stresses in and around the weld by means of extending shortened metal after welding with a columned extrusion head, which is pressed and rotated against the surface of workpiece behind the welding arc. WTRE equipment is simple and easy to implement antomation and friendly to environment with low working noise. Experimental results show that this technology can reduce residual stresses and distortion of thin-plate weldments significantly. With appropriate technological parameters, WTRE can decrease the maximum longitudinal deflection of 2A12T4 aluminum alloy weldments, whose thickness are 2 mm, to below 4% of conventional value.

Key words: Distortion, Thin plate, Welding stress, Welding with trailing rotating extrusion