Numerical investigation of magnetic pulse welding of D9 steel tube to SS316LN end plug using Lagrangian finite element and smoothed particle hydrodynamics (SPH) and its experimental validation

Magnetic pulse welding (MPW) offers a promising alternative to traditional fusion welding techniques for joining dissimilar materials like D9 steel and SS316LN. This study employs a combined finite element Lagrangian and smoothed particle hydrodynamics (SPH) approach to numerically investigate and optimise the MPW of a D9 steel tube to an SS 316LN end plug. The simulation methodology captured the electromagnetic field, structural deformation, and weld morphology with high fidelity. Results demonstrated close agreement between simulated deformation patterns and experimental observations. SPH simulations successfully reproduced metal jet emission, waviness formation, and key field variables, providing valuable insights into the underlying physics and predicting weldability window. Discharge voltage of 17 kV and 18 kV and taper angle of 8 degrees is observed to be best suited as per simulation as well as experiment considering waviness formation as the weldability criteria. X-ray tomography further corroborated the uniformity of the welded region in the working zone. This research underscores the effectiveness of combined numerical and experimental approaches in advancing the understanding and optimisation of MPW processes for dissimilar material joining applications.