What are the pores in stainless steel precision casting that need to be avoided?

Stainless steel precision casting is a casting process with little or no cutting. It is an excellent process technology in the foundry industry and has a wide range of applications. What are the pores in stainless steel precision casting that need to be avoided?
The avoidance of pores in stainless steel precision casting is specifically introduced as follows:
1. Poor air permeability of the coating or insufficient negative pressure, poor air permeability of the filling sand, and inability to discharge the gas and residues in the cavity in time.
2. The pouring speed is too slow, failing to fill the sprue cup, exposing the sprue, entraining air, sucking in the slag, forming a carrying hole and a slag hole.
3. The gasification and differentiation of the foam model generates a lot of gas and residues that cannot be discharged from the mold in time, and the foam and paint layer are filled with dry sand and the dry sand is not dry.
4. Due to the unreasonable planning of the pouring system, the filling speed of the molten metal is greater than the foam gasification concession and the gas discharge speed, forming the filling front, entrap the gasification residue in the metal liquid and vaporize again to form the smoke-black differentiation pores on the inner wall .
5. The joint between the sprue cup and the sprue and the pouring system is not well sealed, especially the joint seal between the sprue and the sprue cup.
6. The particle size of the molding sand is too fine, the dust content is high, the air permeability is poor, and the internal blockage of the negative pressure pipeline constitutes the distortion of the negative pressure.
7. Poor deoxidation of molten steel, unclean slag removal in the furnace base, furnace and ladle, too short calming time, poor slag retention during the pouring process, and unreasonable pouring technology to form slag holes.
8. The pouring temperature is low, and the molten metal at the front of the filling can not fully gasify the foam, and the remaining material will not have time to float to the riser and condense in the casting to form pores.
Stainless steel precision casting pores need to be avoided in the above aspects. Friends who need stainless steel precision casting can contact us.