国外很早就用铈加入铁水中,以改变铸铁中石墨形状,并首次成功地得到球墨铸铁。因为石墨呈片状时易使材料内部产生缺陷,性能较差并容易断裂,由片状转化成球状就大大改善力学性能,而稀土加入铸铁中可起到纯化,变性和合金化的作用。我国在60年代初就将稀土用于球墨铸铁生产,并研制成功稀土柴油机曲轴等重要器件。铸铁中石墨形状介于片状和球状之间的称为蠕墨铸铁。球铁和蠕铁目前广泛应用于机械 Very early abroad, cerium was added to the molten iron to change the graphite shape in the cast iron and for the first time successfully obtained ductile iron. Because graphite flakes prone to make the material within the defect, poor performance and easy to break from the sheet into a ball to greatly improve the mechanical properties, and rare earth into the cast iron can play the role of purification, degeneration and alloying. In the early 1960s, China used rare earth for ductile iron production and successfully developed key components such as crankshafts of rare earth diesel engines. Cast iron in the shape of graphite between the flake and spherical called vermicular graphite iron. Ductile iron and iron are currently widely used in machinery