Abstract: As for the outer-square and inter-circle structure of poloidal field(PF) conductor，the necking process is studied using four rollers by the ABAQUS software. The forming principle for necking deformation，the metal flowing rules and the force situation are analyzed. The four times forming process is designed and the material of conductor is 316L stainless steel whose stress-strain curve is obtained by tensile test. The simulation results show that the distribution of stress and strain in the necking process is uneven and the maximum stress occurred at the back of contact position and the strain is concentrated in the four corner parts which are in accordance with the law of least resistance. The cross-sectional dimension of the deformed conductor is measured in the analysis software and the dimension is within the specified range. The experiment is done on the self-designed molding machine and there are five different cross-sections whose size are measured and averaged. The results are similar with the simulation results which meet the requirement of the conductor size and verify the feasibility of the forming process.

Key words: Molding machine, Necking process, Numerical simulation, Poloidal field(PF) conductor