EFFECT OF PRELIMINARY DEFORMING AND ELECTRODYNAMIC TREATMENT ON STRESSED STATE OF CIRCUMFERENTIAL WELDED JOINTS OF AMg6 ALLOY

摘要

At the present time the methods of control of welded and technological stresses based on preliminary deforming of elements being welded and also electrodynamic treatment (EDT) of welds using pulsed current become ever more developed. The aim of the work is the investigation of influence of preliminary unclamping of edges being welded and EDT on control of stressed state of circumferential welded joints specimens of aluminium alloy AMg6, made using automatic welding in argon. Control of stressed state of specimens was performed using method of electron speckle-interferometry with use of a specialized rigging. The preliminary unclamping of edges was performed using original device for force loading. The values of preliminary tensile stresses reached the yield strength of AMg6 alloy. The EDT was conducted at the surface of deposited metal in the direction "from middle to edges" at a charged voltage of capacitive storage up to 450 V. As a result of carried out investigations it was established that preliminary unclamping and EDT allow significant decreasing of level of residual stresses in circumferential welded joints.