用熔模铸造批量生产的球铁缸体件 (QT4 0 10 )经机械加工后 ,缸体端部表面 (见图 1)出现了大量的孔径为0 .5～ 2mm ,(也有大到 3～ 4mm)的皮下气孔 ,大部分呈球状或雨滴状。经分析 ,认为有以下原因。图 1　缸体皮下气孔处(1)铸造工艺方面 ,端面浇注位置朝上 (图 2 ) ,造成气孔 A large number of holes with a diameter of 0.5-2 mm appear on the end surface of the cylinder body (see Fig. 1) after machining with a cast iron cylinder block (QT4 0 10) 4mm) subcutaneous stomata, mostly spherical or raindrop-shaped. After analysis, that there are the following reasons. Figure 1 cylinder subcutaneous air holes (1) casting process, the end pouring position up (Figure 2), resulting in pores