Precautions for Low Pressure Casting

The low-pressure casting process has been passed down for a long time, but there are also many shortcomings. The following issues should be paid attention to in order to prevent low-pressure casting from being under-injected and cold-separated:

1. The shape of the casting should be as streamlined as possible to avoid sharp edges and sharp changes in connection with other structural shapes to facilitate the flow of metal liquid. The thickness of the casting should be appropriate and not too thin, especially when the contour of the casting is large. If it is too thin, a large horizontal surface should be avoided, because it makes the metal liquid rise slowly when the casting is poured, the surface in contact with air is large, and it is easy to oxidize. At the same time, due to the rapid heat dissipation of the metal mold, the metal liquid quickly loses fluidity. Causes defects such as insufficient pouring, cold insulation, slag inclusion, etc.

2. It is also related to the position of the casting surface. The casting surface that has a tendency to detach from the surface of the metal mold when the casting is cooling and shrinking can be designed with a smaller slope, and the surface of the casting that tends to be pressed on the metal mold when the casting shrinks. Larger slopes should be given. Casting slopes for stainless steel castings of various alloys;

3. In order to prevent the casting from shrinking, shrinking, porosity and crack defects, the wall thickness should be uniform, sharp and right-angled structures should be avoided, sawdust in the molding sand, coke in the core, and hollow Core and oil sand core, etc. to improve the concession and permeability of sand or core.

Because of the shrinkage of stainless steel precision casting, the shrinkage of stainless steel castings greatly exceeds that of cast iron. In order to prevent shrinkage and shrinkage defects in castings, most of the measures used in the casting process are feeders, cold iron and subsidies to achieve sequential solidification. Low-pressure cast stainless steel has higher mechanical properties than cast iron. Stainless steel precision casting is suitable for casting of various types and alloys.