中文摘要：

由于铁的磁化特性，对于铁包套的MgB2线材来说，线材的截面形状和铁包套的厚度都会影响到MgB2超导芯的磁场，进而影响到MgB2线材的载流能力。文中将建立几种典型的单芯及多芯MgB2线材模型，并利用有限元方法（finite element method，FEM）分析铁包套对这些模型中超导芯的最大磁场Bmax和临界电流密度Jc，经过对这几种典型结构的载流能力进行比较，可以得到一些有益于改善铁包套MgB2线材的载流能力的合理性建议。

英文摘要：

Because of the ferromagnetism of the Fe sheath, the shape of the MgB2 wires and the thickness of the Fe sheath affect the magnetic field in superconducting cores, and accordingly affect the current carrying capability of MgB2 wires. In this paper, the models of mono-- and multi--filament MgB2 wires were built. The effects of Fe--magnetization on Bmax and Jc of these models have been analyzed with finite element method. The current carrying capability of RW, FT, and 7RW has been compared considering the effect of magnetic shield. The results can give some suggestions on the structures of Mg2/Fe wires to improve the current carrying capability.