【摘要】 利用OM、SEM和XRD研究了不同制备工艺的氧硫复合孕育剂对球墨铸铁显微组织和性能的影响。结果表明:机械混合工艺制备的孕育剂由Si相、Fe_0.42Si_2.67、FeSi₂、LaSi₂和FeS相组成,各元素分布较为均匀,未出现大量氧、硫元素聚集;而烧结工艺制备的孕育剂物相组成中出现了LaSi相,并有明显的氧、硫元素的聚集。使用不同制备工艺的氧硫复合孕育剂制备的球墨铸铁抗拉强度和布氏硬度均高于使用硅钡钙孕育剂制备的试样。并且机械混合工艺制备孕育剂处理的球墨铸铁的抗拉强度和布氏硬度均最高,分别为533 MPa和HBW 168.7。主要原因是机械混合工艺制备孕育剂处理球墨铸铁的石墨球数量最高和圆整度最优,从而有效增强球墨铸铁抵抗塑性变形的能力。更多还原

【Abstract】 The effect of oxygen-sulfur compound inoculant fabricated by different preparation processes on the microstructure and properties of ductile iron was studied by using OM, SEM and XRD. The results show that the inoculant prepared by the mechanical mixing process is composed of the Si phase, Fe_0.42 Si_2.67, FeSi₂, LaSi₂ and FeS phase, the distribution of each element is relatively uniform, and there is no phenomenon of a large amount of oxygen and sulfur elements aggregation; however, the phase constituents in the inoculant prepared by the sintering process appear a new LaSi phase, and there is obvious aggregation of oxygen and sulfur elements. The tensile strength and Brinell hardness of the ductile irons treated by oxygen-sulfur compound inoculant under different preparation processes are better than those treated by silicon-barium-calcium inoculant. And the tensile strength and Brinell hardness of the ductile cast iron treated with the inoculant prepared by the mechanical mixing process are the highest, which are 533 MPa and HBW 168.7, respectively. The main reason is that the ductile iron treated with the mechanical mixing process has the highest number and the best roundness of graphite spheres, which effectively enhances the ability of the ductile iron to resist plastic deformation.更多还原