选用近期实验所测较为准确的稀土-氧、稀土-硫、稀土-氧-硫体系的热力学数据建立了纯铁液中的[Ce]-[O]-[S]空间沉淀图。应用热力学理论计算了铁液中氧硫活度与生成的稀土夹杂物间的定量关系。确定了铁水初始氧硫活度与生成稀土夹杂物类型的关系,并验证了理论计算结果。 The precipitation of [Ce] - [O] - [S] in pure molten iron was established by thermodynamic data of rare earth-oxygen, rare earth-sulfur and rare earth-oxygen- The thermodynamic theory was used to calculate the quantitative relationship between the activity of sulfur and sulfur in the molten iron and the generated rare earth inclusions. The relationship between the initial oxysulfide activity and the types of rare earth inclusions was established, and the theoretical calculation results were verified.