硫对灰铸铁组织和性能的影响

Effect of Sulphur on Structure and Properties of Gray Iron

在电炉熔炼条件下,采取往铁液中加入FeS增硫的方法,研究和探讨了硫对灰铸铁组织和性能的影响。试验结果表明:硫从0 020%上升到0 061%,灰铸铁强度可提高50MPa以上,硬度值可提高20个HB,灰铸铁白口倾向减小,A型石墨增多,断面均匀性得到改善,进一步提高硫到0 101%时,上述指标值变化不大。此外,用电子探针对灰铸铁组织进行的微区分析发现,石墨内部有大量的Si、Ba、S和Mn等元素的富集,据此可以认为,上述元素的硫化物在灰铸铁凝固过程中起着石墨形核的基底作用。

The effects of sulphur on the structure and properties of gray iron were studied by adding FeS into melted iron to increase the sulphur content under the condition of induction melting in this paper. The experimental results show that the method may increase the tensile strength by 50 Mpa and the hardness by 20 HB of gray cast iron, decrease the chilling tendency, improve the graphite morphology, reduce the wall thickness sensitivity and raise the content of A graphite morphlogy by increasing the sulphur content up to 0.023%～0.061%. But the structure and properties of gray iron weren't varied very much by increasing the sulphur content up to 0.061%～0..101%. By using the electronic scanning probe, it was observed that Si, S, Mn, and Ba etc. concentrate in graphite. It can be considered that the sulphids of these elements play a positive role of graphite nucleation substrates in the solidification of gray iron.