Mathematical Approach to the Stress-Strain State of AMg61 Alloy Weld Joints during their Electrodynamic Treatment on Fusion Welding

Mathematical simulation of stress states arising in butt weld joints of AMg61 aluminum alloy plates (δ = 2, 4, and 8 mm) induced by electrodynamic treatment (EDT) at different temperatures was performed. The vertical velocity V₀ of the indenter electrode (EDT tool), determined by the energy characteristics of EDT equipment, was taken to be V₀ = 5 m/s. The T values were set to represent the EDT conditions after welding (20°C) and during fusion welding (150 and 300°C). The three-dimensional problem was solved by the finite element method using an ANSYS software package. The conditions for the stresses arising in the EDT plates after and during welding were defined by the mechanical characteristics of an AMg61 alloy at 20, 150, and 300°C, which were described by the kinematically-hardened material model. The computational results for kinetics and residual stress states in weld joints are presented. EDT at 150°C (during welding) was established to be more effective than that at 20°C (after weld cooling). EDT of weld joints (δ = 2–4 mm) was found to result in residual compression stresses across the whole width of the plate, with their values being close to the yield strength of an AMg61 alloy. EDT of weld joints (δ = 8 mm) generates residual compression stresses on the outer plate surface and the tensile ones on its back surface. Thus, for optimum residual stress states of weld joints with δ = 2–4 mm, one-sided EDT (at given V₀) is sufficient, while for δ = 8 mm, two-sided EDT would be required.