What factors will affect the surface finish of investment casting?

1. Raw materials, such as molding sand, can be divided into circular square and triangle. The worst one is triangle. The gap is very large (if it is resin sand molding, it will continue to increase the amount of epoxy resin, of course, it will also increase the gas generation at the same time. If the exhaust pipe is bad, it will be easy to produce air holes). It is annular sand. If it is pulverized coal fine sand, the preparation of sand (sand strength and environmental humidity) will also have a great impact on the external shape. If it is carbon dioxide hardened sand, it mainly depends on architectural coatings

2. Materials. If the composition of EPC manufacturing parts is unbalanced, such as low manganese, it is easy to loose, and the surface material is thick

3. Casting system software, if the casting system software is not scientific, it is also easy to cause loose castings, and very seriously, there will be a phenomenon that castings can not be poured into EPC processing, or even can not be made into complete castings.

4. Slagging. If the slag in the molten iron is not cleaned or the slag is not covered during casting, so that the slag runs into the die, there must be slag holes

5. Human factors. Because of carelessness, the sand was not cleaned or fell into the box when the box was closed. The molding design is that the sand is not solid, or the sand preparation is not scientific, and the compressive strength of the sand is insufficient. Sand holes may occur in the castings of EPC manufacturers

6. If the sulfur and phosphorus exceed the standard, the casting will crack. This is a matter that must be considered before production or specific guidance for production, so as to ensure the quality of the casting.

The reasons mentioned above are only a small part of them. Because forging production is various, it is difficult to understand the anomalies, and difficulties encountered before production often occur. Sometimes a problem can not be found for a long time.