一、指甲盖状缺陷的产生图1为我厂采用金属型浇注的气缸盖铸件,其材质是ZQAL9-2,铸件耍求经机加工后,在气压为225kgf/cm2状态下,保压5 min不得泄漏。在设计铸造工艺时,金属型按图示方向水平分型,立注底浇。但从浇出的第一批数十个铸件冷却后发现,所有铸件在A处均产生了如指甲盖般的夹层缺陷,有的用凿子轻轻一凿就能掉下,其厚度为3mm左右,铸件因此而报废。 First, the nail-shaped defects produced Figure 1 for our factory using metal casting cylinder head castings, the material is ZQAL9-2, castings require machining, at a pressure of 225kgf / cm2 state, holding pressure 5min Do not leak. In the design of casting process, the level of the metal type according to the direction of the sub-type, legislation Note pouring at the end. However, pouring out the first batch of dozens of castings after cooling found that all the castings produced fingernail-like mezzanine defects at A, some with a chisel can be a chisel can fall, the thickness of about 3mm , Castings scrapped accordingly.