Effect of coil length and relative position on electromagnetic tube bulging

A loose coupling method is adopted to study electromagnetic tube bulging, and effect of processing parameters on electromagnetic tube bulging is analyzed. The results show that critical relative length increases with the increasing of coil length, when coil approaches infinite length, critical length approximates 1. With the rise of relative position, radial magnetic pressure acting on the top end of tube increases, when relative position is equal or greater than 30 mm, radial magnetic pressure of tube top end remains unvaried. Relative position of 30–50 mm is optimal position for electromagnetic tube flanging.