Bucket teeth are the main wearing parts of open pit buckets. The weight of the casting is 130kg, the material is ZGMnl3, and the size is 944mm*300mm*150mm. Such castings are usually produced by traditional sand casting process. EPC has many technical and economic advantages.
(1) Coreless, the core making process and related equipment can be omitted.
(2) There is no parting surface, no gap between the cores, and no flash and burrs in the casting.
(3) Without considering the negative parting and negative core, the dimensional accuracy of the casting can be improved by reducing or even canceling the draft slope.
(4) The foam mold is easy to bond and assemble.
(5) Good working environment and low production cost.
In order to give full play to the advantages of EPC and improve the yield of the process, bucket teeth can be cast by group casting. Bottom-drawn negative pressure sand boxes are used, 10 are placed in a box, the bucket teeth are pointed down, the sand boxes are parallel to each other, and 5 are placed on both sides of the runner. A closed pouring system is adopted without air bubbles.
When pouring, the direct runner is poured in an orderly manner, which is smooth and fast, so that the molten steel is always filled with the sprue cup until the pouring is over. In this way, the EPS in the direct flow channel is quickly vaporized and filled with steel in a short time, which can effectively prevent the negative pressure from sucking the gas into the mold cavity, and at the same time establish a certain static pressure in the mold cavity. cavity. The gating system makes it difficult for the steel to be involved in gas and residue during the filling process, which can effectively avoid defects such as pores and residue, and at the same time prevent waste castings caused by partial collapse.
The castings obtained by EPC are in good shape and fully meet the requirements of geometric dimensions; the surface quality of castings is good, without burrs, shrinkage cavities, pores, and risers; the workload of cleaning and cutting is reduced by 50%; compared with traditional sand casting, the yield of castings is increased by 40% %above.