Optimization of Process Parameters in Electro-Magnetic Welding of D9 Tube to SS316 L (N) Plug

In electro-magnetic welding (EMW) process, optimization of process parameters is very important aspect. Optimization process leads to generation of mechanically and metallurgically sound interface weld without overstressing tool coil and electromagnetic welding equipment. This work investigates the effect of four important process parameters (Magnetic field in coil ID, Frequency of current pulse, Taper angle of SS316 L (N) plug and Stand-off distance between D9 tube and SS316 L (N) plug) on weld quality and their optimization. Multiple experiments were conducted to arrive at optimized value of above mentioned process parameters which generated heat effected zone free, mechanically and metallurgically qualified interface weld of reasonable length. The welded interface revealed a wavy morphology of 35 - 40 μm as maximum crest height and lowest helium leak rate of 4 × 10？10 m？bar？L/s. Experimental results have proved that 27 T magnetic field is needed in coil ID to produce optimum weld quality at interface. Experimental data has proved that at higher frequency, similar quality of electro-magnetic welding can be obtained at lower bank energy. Experimental results have also proved that taper angle of 8？ produces weld interface at lowest possible magnetic field in coil ID. It is also proved experimentally that 0.5 mm stand-off distance produces better weld length as compared to no stand-off distance and 1.0 mm stand-off distance.