球墨铸铁件冒口补缩失败原因分析——球墨铸铁缩松、缩孔问题探讨(二)

Analysis of Reasons Causing Riser/Feeder Feeding Failure in Nodular Iron Castings Production--An Approach to Shrinkage Problems of Nodular Cast Iron (Ⅱ)

除铸型刚度和铁液冶金质量外,球铁件冒口补缩失败的原因主要是:①采用冷冒口和明冒口;②冒口设置位置不当;③冒口直径或/和高度偏小;④内浇道不能在浇注结束时及时凝固;⑤铸件存在与冒口补缩通道不相通的孤立热节;⑥薄、小件补缩通道窄小,冒口补缩不进等。

In addition to mould rigidity and metallurgical quality of molten iron, the main reasons causing riser/feeder feeding failure in nodular iron castings production are:(a)open and cold metal flowing-off risers were used; (b)feeder location not proper; (c)feeder too small or/and too low; (d)ingates couldn't freeze up instantly after pouring stopped; (e)there're isolated hot spots in the casting which weren't connected with feeding channel of the feeder ;(f)fceding channel of small and thin section castings too nar-row for feeding liquid to enter into castings;and so on.