Investment casting to avoid porosity of prevention 

1.In the precision casting conditions allow, the complex structure of casting the top. Set the vent.2. When designing gating system, to fully consider the shell exhaust demand. 

3.The shell roasting temperature, time to reasonable, heat preservation time is enough. 

4.When the dewaxing wax material should be completely ruled out. 

5. The appropriate to reduce the ladle mouth to flood basin distance, casting speed wants even, to ensure smooth full of cavity of molten steel, as little as possible involvement in the molten steel in the air, so that in the cavity and the molten steel gas energy discharge smoothly.