西德Buderus冶金厂等单位从事汽缸盖铸铁的研究。自1970年以来制造汽缸盖的蠕虫状石墨铸铁材料得到发展,目前已用于成批生产。蠕虫状石墨铸铁(以下简称蠕铁)弥补了片状石墨铸铁和球铁的缺陷,在标准灰铸铁中,石墨以蠕虫状出现。制造蠕铁可以在熔炼时加Mn,Ti处理,或加稀土合金处理。在某些情况下,可使用Ce改变凝固过程,使它的缩孔小于球铁。 West Germany Buderus Metallurgical Plant and other units engaged in the research of cylinder head cast iron. The worm-shaped graphite cast iron material that makes the cylinder head since 1970 has been developed and is currently used in mass production. Worm-like graphite cast iron (hereinafter referred to as vermicular iron) makes up for the flake of flaky graphite cast iron and ductile iron, which appears as worm-like in standard gray cast iron. Manufacture of vermicular iron can be added in the melting of Mn, Ti treatment, or rare earth alloy treatment. In some cases, Ce can be used to change the solidification process so that its shrinkage is smaller than that of ductile iron.