原料配比对球墨铸铁珠光体片层间距及硬度的影响

Effects of Raw Material Proportioning on Pearlitic Lamellar Spacing and Hardness of Ductile Iron

采用不同配比的生铁和废钢,硅铁及电极石墨作为增碳剂,在相同铸造工艺下,制备化学成分基本相同的球墨铸铁,并对试样的显微组织和硬度进行了分析。结果表明,原料配比对球墨铸铁中珠光体的形态、片层间距的大小以及球铁的硬度存在显著的影响。随着原料中生铁所占比例的降低,球铁基体中珠光体的片层间距逐渐减小,球铁的硬度逐渐升高。特别是全部使用废钢生产时,球铁硬度较大幅度地提高。

With the same casting technique,the ductile irons with the same chemical composition were made by the different mixture ratio of pig iron,scrap steel,ferrosilicon and electrode graphite.The microstructures of the specimens were analyzed,and the hardness values of them were tested.The results show that the raw material proportioning has obvious effects on pearlitic pattern,pearlitic lamellar spacing,and hardness of ductile iron.The pearlitic lamellar spacing of the matrix decreases,and the hardness of the ductile iron increases with the pig iron proportion decreasing.Especially when ductile iron is made of full scrap steel,the hardness increases by a large margin.