Numerical simulation and experimental analysis of weld forming for electromagnetic pulse welding with aluminum to steel

To clarify the formation process of the weld seam in aluminum/steel electromagnetic pulse welding, the Ansys Maxwell finite element method was adopted to simulate the collision process of the 6061-aluminum alloy cladding plate and the 304 stainless steel plate by loading an external circuit. The Vickers hardness, EBSD and XRD tests were also conducted. The results show that the simulation results of the electromagnetic force distribution law, the rebound process of the aluminum plate and the weld seam morphology are consistent with the experimental data. The induced current density determines the contour characteristics of the weld seam, which is mainly concentrated on the lower surface of the aluminum plate above the middle beam of the coil, with a normal distribution, the maximum value being 17.7 × 10⁹ A/m², presenting a symmetrical rectangular loop feature. There is a strong magnetic field aggregation effect at the lap joint and the boundary of the aluminum plate. The electromagnetic force density is the highest at the position directly opposite the aluminum plate on the middle beam, reaching 27.3 × 10¹⁰ N/m³, causing the steel plate to rebound instantaneously and the welding not to be achieved. Under the effect of magnetic field aggregation, the microstructure at the stainless steel weld changes from FCC to BCC.Moreover, within the range of the electromagnetic force density formed at the weld, the greater the electromagnetic force density, the greater the transformation amount, and the more obvious the hardness strengthening. The research results provide data references for reducing the rebound area, increasing the weld seam area and improving the joint strength.