硫是成型铸钢件中最有害的夹杂,它不仅使钢铸件产生热脆性和热裂,而且剧烈降低钢的机械性能和其他质量指标。只有当硫化合成 MnS 或其他硫化物(Al_2S_3、ZrS_2、CaS)而作为结晶核心或不以易熔化合物及薄膜分布于晶界上时,才有可能在含硫较高时获得没有裂纹的铸件。按化学计算法,锰的最低含量应为硫的1.71倍。实际上, Sulfur is the most detrimental inclusion in forming steels, which not only creates hot brittleness and thermal cracking in steel castings, but also severely reduces the mechanical properties and other quality specifications of the steel. It is only possible to obtain a crack-free casting at high sulfur contents only if sulfides are used to synthesize MnS or other sulfides (Al 2 S 3, ZrS 2, CaS) as crystalline nuclei or not on the grain boundaries with fusible compounds and films. According to the stoichiometric method, the minimum content of manganese should be 1.71 times that of sulfur. In fact,