The impact of casting properties on the slag pot

During the solidification and shrinkage of the slag pot, it is subjected to the resistance of the mold, the greater the resistance, the slag pot is easy to break, so the collapsibility of the mold plays an important role in the formation of hot crack of the slag pot. The collapsibility of the mold is good, the resistance of the slag pot is less, and the possibility of forming hot crack is also small. The collapsibility of wet type is better than that of dry type, and the slag pot cast by solid-wet type is not easy to form hot crack. The effect of mold collapsibility on hot cracking is not only related to the size of collapsibility, but also to the time of collapsibility. If the molding sand is heated and the compressive strength of the core increases, and if the strength of the core reaches a large value, which coincides with the time when the solidification of the slag pot is about to end, there is a great possibility of hot cracking. Therefore, the collapsibility of the mold can prevent the slag pot from hot cracking.

The influence of casting conditions. The influence of casting process on the hot cracking of slag pot is various, and it should be selected according to the wall thickness of slag pot.

The thin-walled slag pot requires high temperature and fast pouring to make the solidification rate slow and uniform so as to reduce the tendency of hot cracking. On the other hand, too high pouring temperature of thick-walled slag pot will increase the shrinkage volume, slow down the cooling rate, coarsening the primary crystal, form segregation and sticking sand, and thus promote the formation of hot cracking. Therefore, when the conditions permit, it is appropriate to pour slowly at low temperature.

The influence of casting system on hot cracking can not be ignored. Generally, the temperature near the pouring riser is high, the cooling is slow, and cracks are easy to occur. Therefore, a reasonable gating system is designed and the correct pouring process is determined. Reducing the hindrance of the pouring riser to the shrinkage of the slag pot can prevent the slag pot from hot cracking.

The influence of slag pot structure. Whether the structure of the slag pot is reasonable or not has a great influence on the hot crack of the slag pot. In the design of the slag pot, the sudden change of wall thickness should be avoided as far as possible. Proper fillets should be made at the corner of the slag pot. Avoid wall or rib crosses. Reduce hot nodes and prevent stress concentration.