How to prevent cavities in iron castings

Surface of iron castings may sometimes develop pinhole-sized cavities, which significantly reduce their intended effectiveness, indicating the presence of gas hole defects in the iron castings. There are many reasons for the occurrence of gas hole defects, and correspondingly, many preventive measures. The main reasons for bubble formation in iron castings are as follows:

first, the venting of the mould does not achieve the desired effect. 

Second, the molten liquid has not undergone degassing treatment, and the temperature during melting is excessively high. 

Third, the mould temperature is too high, causing insufficient solidification time and low strength of the metal. Fourth, there are too many release agents, affecting the iron casting process. 

Fifth, the design of the internal pouring gate is poor, leading to unsmooth pouring of the molten material. 

There are many methods to prevent gas hole defects in iron castings, and I will share them one by one.

Firstly, during the production of iron castings, the filling degree of the molten metal should be improved, and the flow rate of the molten liquid should be decreased initially; also, remember to lower the mould temperature. The degassing treatment of the molten liquid should be properly handled, and adjustments can be made to the process to achieve the optimal effect. For various defect issues arising during the production of iron castings, the technical department should take corresponding preventive measures based on the specific characteristics of the defects.