为了提高铸件质量,我们对铸铁件废品进行了全面的统计分析,反映出下述情况: 废品中以叶轮零件的废品居首位,而叶轮废品又以气孔、夹渣为主要缺陷。叶轮铸件壁较薄,一般为2～6毫米。其凝固速度快,凝固时气体和熔渣不易上浮排出,另一方面,外部的气体也不易侵入铸件。气孔的形状大多呈析出型和反应型两类。因此,叶轮铸件的废品与铁水本身质 In order to improve the quality of castings, we carried out a comprehensive statistical analysis of cast iron scrap, reflecting the following conditions: the wastes of impeller parts are the top among the wastes, and the impeller holes and slag inclusions are the main defects. Impeller casting wall is thin, usually 2 to 6 mm. The solidification speed, solidified gas and slag is not easy to float out, on the other hand, the external gas is not easy to invade the casting. Most of the stomata are precipitated and reactive. Therefore, the castings of impeller and the quality of molten iron itself