Si/C和冷却速度对中铬铸铁铸态组织性能的影响

Influences of Si/C and Cooling Speed on the Structure and Properties of Medium-chromium Cast Iron As-cast

研究了Si/C和冷却速度对中铬铸铁铸态组织和性能的影响规律。试验表明 :在一定限度内提高Si/C能改变碳化物的类型和分布 ,使冲击韧性大幅提高 ;增加冷速使组织明显细化 ,特别是使奥氏体的一次、二次枝晶臂间距显著减小 。

The influences of Si/C ratio and cooling speed on the as cast structure and properties of medium chromium cast iron were investigated. The experimental results indicate that by increasing Si/C ratio within a certain limitation the morphology and distribution of carbides can be changed and its impact toughness can be improved remarkably. By increasing the cooling speed, the structure of casting can be refined obviously; especially the primary and secondary dendrite arm spacing of austenite can be decreased evidently, so that integrative mechanical properties are improved.