减少大型球墨铸铁气缸盖缩松缺陷探讨

Discussion on Reduction of Dispersed Shrinkage in Large Ductile Iron Cylinder Head

某大型球铁气缸盖在生产过程中缩松缺陷问题突出,尤其在气门导管孔和斜油孔部位,严重影响铸件成品率。借助MAGMA模拟分析软件,确定了缺陷产生的原因并对冒口、冷铁、浇注温度和合金液碳当量等进行了工艺优化。经生产验证,缩松缺陷问题显著改善,废品率大大降低。

Dispersed shrinkage defects were obviously generated in a large ductile iron cylinder head in the process of production, especially at the positions of valve guide holes and oblique oil holes, which seriously affected the yield of castings. In the paper, by using the MAGMA simulation software, the causes of the defects were analyzed and the technical process was optimized including risers, chills, pouting temperature and carbon equivalent of the ductile iron. Through verification by production, it was found that the problem of dispersed shrinkage defects in the large ductile iron cylinder head was solved effectively and the rejection rate of the castings was reduced greatly.