What must be prevented in stainless steel precision casting blowholes?

Stainless steel precision casting is a forging process with little or no drilling. It is an excellent production process in the foundry industry and is widely used. What must be prevented in stainless steel precision casting blowholes?

The actual prevention of pores in stainless steel precision casting is described in detail as follows:

1. The air permeability of architectural coatings is poor, the negative pressure may not be enough, and the air permeability of the filled sand is poor, so the vapor and residues in the die cannot be discharged immediately.

2. The pouring rate of the stainless steel casting gate is very slow, and it cannot fill the plastic inlet cup, the sprue is exposed, the gas is involved, and the slag is sucked in. The carbon steel series-water glass is composed of air holes and slag holes.

3. The solid model of foam plastic is gasified and split into many vapors and residues that cannot be immediately discharged for casting. It is not good for foam plastic and architectural coating layers to be filled with dry sand.

4. Due to the unscientific overall planning of the casting management system, the filling rate of the metal material liquid exceeds the gasification compromise of the foamed plastic and the gas discharge rate, and the formation of the filling Z front will break the ball of the gasification residue in the liquid metal material again. Formed into soot-black split stomata in the lumen.

5. The sealing of the joint between the sprue cup and the sprue and its pouring management system is not good, especially the joint of the sprue and the glue inlet cup is not well sealed.

6. The particle size distribution of the sand is too fine, the dust composition is high, the air permeability is poor, and the internal blockage of the negative pressure pipeline causes the negative pressure to lose frames.

7. The deammonia of molten steel is not good, the slag discharge in the stove, the furnace and the bag is not clean, the time is too short, the slag blocking is not in place during the whole pouring process, and the pouring technology of the valve fittings snail pump is unscientific to form the slag hole.

8. The pouring temperature is low, and the metal material liquid at the front of the filling mold cannot fully vaporize the foam plastic, and the remaining chemical substances cannot catch up with the flotation to the riser and solidify in the casting to form pores.