喷吹法蠕化处理蠕墨铸铁的组织及性能研究

Microstructure and Properties of Vermicular Graphite Cast Iron Treated by Injection Process

研究了喷吹法处理蠕墨铸铁的组织及性能,以及该工艺条件下壁厚与蠕化率的关系。以惰性气体为载体,将颗粒状镁球和稀土合金喷吹到铁液中,实现铁液蠕化。研究发现,用纯镁粒配以少量稀土合金处理铁液时可以获得好的蠕化效果,可以大幅降低稀土类蠕化剂的加入量,降低生产成本,铸件蠕化率与铸件壁厚有关,随着壁厚增加,蠕化率呈增大趋势。试验结果表明,喷吹法处理蠕铁,蠕化稳定性较好,蠕虫状石墨形态好,石墨分布均匀,蠕化率较高,力学性能良好。

The microstructure and properties ofvermicular cast iron treated by injection process were studied respectively, and the relationship between the thickness and percentage ofvermiculation was also investigated. The granular magnesium and small amount of rare earth alloys were injected into the molten iron to obtain the vermicular graphite. The experiment shows that good verrnicular effect can be achieved by injecting pure granular magnesium and small amount of rare earth alloys; the addition of rare earth alloys can be greatly reduced and the cost can be reduced. The vermicular graphite rate is related to the casting thickness, with the increase of wall thickness, the vermicular graphite rate shows an increase trend. It has been proved that the vermicular cast iron treated by injection process is relatively stable with better vermicular graphite morphology and uniform distribution of graphite, and higher the vermicular graphite rate was obtained, the castings presented good mechanical properties.