Magnetic pressure in electromagnetic tube forming with echelon coil

The effects of geometrical characteristics of echelon coil on the magnetic pressure distribution and their contribution to the final shape of parts were focused and investigated through experiments and numerical simulation using FEM software ANSYS.The results show that the geometrical characteristics of echelon coil play a key role in controlling the magnetic pressure acting on the tube．They show a hump·like distribution near the interface between bigger diameter region and transition region of echelon coil,and affect the final shape of tubular parts then.With the reduction of relative diameter,the magnetic pressure in smaller diameter region decreases and its distribution gradient in transition region increases.With the augment of relative length,the magnetic pressure increases in bigger diameter region,while it almost remains constant in smaller diameter region,and the gradient in transition region enhances sharply.The distribution of magnetic pressure in the axial direction of tube agrees well with the profile of specimen.