我厂自1980年以来,对大断面的铸铁件(包括灰铁和球铁),实行了无冒口铸造。四年多来取得了理想的效果:铁水收得率达95％,且铸件内部组织致密。现将情况介绍如下,供参考。一、原理铁水注满型腔后,随着温度的下降,在凝固过程中,其体积变化,不仅仅随着冷却而发生收缩,同时由于石墨析出等原因体积也会膨胀,其体积变化的一般规律如图1所示。图中a为液态 I plant since 1980, the large section of the cast iron pieces (including gray iron and ductile iron), the implementation of a non-riser casting. In the past four years, the ideal effect has been achieved: the yield of hot metal reaches 95% and the internal structure of the casting is dense. The situation is as follows, for reference. First, the principle After the molten iron filled cavity, with the temperature drop in the solidification process, the volume change, not only with the cooling and shrinkage occurred at the same time due to graphite precipitation and other reasons the volume will be expanded, the volume changes in general The law shown in Figure 1. A is liquid