ITER PF导体缩径成形工艺研究

针对超导极向场(Poloidal field, PF)超导导体外方内圆的结构特点，以ABAQUS软件分析为手段，采用四辊轮缩径成形工艺对导体缩径成形进行研究。对缩径成形原理、变形区金属的流动规律和横截面受力情况进行理论分析，设计四道次成形工序，并通过拉伸试验获得导体材料316L不锈钢的应力应变曲线。数值模拟结果表明导体缩径过程中应力应变分布不均匀，最大应力出现在接触位置后端，应变集中在四个圆角部位，符合金属流动最小阻力定律。在分析软件中测量变形后导体的截面尺寸，在规定的使用范围之内。在自主设计的成形机上进行试验，取5个不同截面测量尺寸并取平均值，所得结果与模拟结果相近，符合导体尺寸要求，验证了该成形方案的可行性。

Research on the Necking Process of ITER PF Conductor

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.