因型表层受热膨胀而造成的铸件缺陷(以下简称膨胀缺陷),在湿型铸造的生产条件下,极为常见,比较严重的,铸件表面上凸起一片不平整的金属,像牛皮癣一样,将它剔开,就会发现这层金属下面夹着一片型砂。这种缺陷,通常大家都称之为“夹砂”,如图1 a所示,也有人叫它做结疤、起夹 Due to thermal expansion of the surface caused by casting defects (hereinafter referred to as swelling defects), in the wet casting conditions of production, is extremely common, more serious, casting a bump on the surface of an uneven metal, like psoriasis, it will be Check out, you will find this layer of metal sandwiched between a sand. This defect, usually we all call it “sand”, as shown in Figure 1a, it was also called scabs,