球墨铸铁件的补缩

Feeding for Ductile Iron Castings

结合铸造生产实践，总结了几种行之有效的球墨铸铁件补缩方法，分析了一种有效冷冒口的作用机制，指出树脂砂芯在金属液的热作用下产生的大量气体进入冒口，对其中的金属液进行了物理搅拌，并与其发生放热化学反应，推迟了冒口颈及冒口本体的凝固进程；当厚大热节存在于铸件最高处时，冷铁和冒口并用是既经济又有效的工艺方法。

Combined with the production practice of casting, several effective feeding methods for ductile iron castings were summarized. The mechanism of action for an effective cold riser was analyzed. It＇s pointed out that the resin sand cores under the thermal effects of molten iron generate a lot of gas to enter the riser, in which the liquid metal is agitated by gas to occurre exothermic reactions. The solidification process of metal both in riser and its neck are put off. While a thick hot spot on the top of a casting, using both a proper riser and some chills is an economical and effective technological process.