半固态过共晶高铬铸铁浆料在离心力作用下的凝固组织

Solidification Microstructure of Hypereutectic High Chromium Cast Iron Semi-solid Slurry in Centrifugal Casting

对于倾斜冷却体法制备的半固态过共晶高铬铸铁浆料,采用离心铸造法将其制备成环形铸件,并观察和分析该铸件组织。结果表明,首先在半固态组织中初生碳化物出现偏析现象,且存在明显的偏析分界线,分界线位于距离环形铸件径向外侧面约6mm处。其次,在本试验条件下,离心力的作用只能部分消除半固态过共晶高铬铸铁组织中的缩松倾向,而且在组织中也存在缩松出现的分界线,即小于距环形铸件径向外侧面约6mm的径向区域内无缩松产生,大于距环形铸件径向外侧面约6mm的径向区域产生缩松。

The microstructure of annular parts in centrifugal casting has been observed, in which hypereutectic high chromium cast iron semi-solid slurry prepared by slope cooling body method is used. The results indicate that not only segregation phenomenon of primary carbide in the semi-solid structure but also sharp dividing line of the segregation, where the dividing line locates at the distance of about 6 mm from the radial outer face of the annular parts, can be observed. At the given experimental condition, the shrinkage porosity tendency in the structure can only be partially eliminated by centrifugal forces. The dividing line of shrinkage porosity appearance in the microstructure also locates at the distance of about 6mm from the radial outer of the annular one, that is, as the distance from the radial outer of the annular one is less than 6mm, there are no shrinkage porosities in the radial area, contrarily, there are shrinkage porosities.