金属型铸造高压壳体铸件中气孔的形成分析

Analysis of Gas Holes Formation in High Pressure Shells Under Metal-mould Casting

通过实验研究了金属型铸造高压壳体铸件中气孔的形成原因。通过检测发现,铸件的表面和内部都存在气孔。分析表明,铸件的表面气孔是由于涂料的发气造成的;内部气孔是由于铝液的含气量过高造成的。气孔形态表现为析出性气孔和侵入性气孔。因此,要加强铝液的除气和净化工艺,以消除铸件中的气孔。

The reason for forming gas holes in high pressure shells was experimentally studied under metal-mould casting.The results show that there are gas holes in the surface and the casting;the surface holes are caused by forming gas in coatings,and the deep-seated blowholes are due to excessive gas content of liquid-Al.The morphology of gas holes has two forms： precipitating gas holes and irruptive gas holes.Consequently,the degassing and purification process for liquid-Al should be improved in order to eliminate gas holes.