What to do if there are pores in flange castings

The process improvement measures taken when there are pores in flange castings are as follows:
Reduce the amount of gas generated by the cold core box sand core
Ensure the tensile strength of the sand core by adjusting the ratio of the resin components of the cold core box sand core Under the premise, adjust the proportion of components to reduce the amount of gas generation.
, Reduce the gas generation volume of the sand mold
Because the upper columnar core and the inner cavity oil passage core are made of coated sand. On the premise of ensuring the basic strength that meets the requirements for sand core circulation and use, it is appropriate to develop low gas generation coated sand with a gas generation volume of about 100%.
. Change the sand coating method
The sand coating method is changed from the overall spraying of water-based paint to the method of overall spraying of water-based paint and partial manual brushing of alcohol-based paint. When painting by hand, apply alcohol-based paint and use fire immediately after applying the paint