How to prevent casting grade chromite sand from sticking to sand
1. Chromite sand is not easily wetted by high-temperature molten steel. The liquid steel has high transparency and is not easy to penetrate into the sand and form mechanical sand. Chromite sand has good resistance to alkaline slag and does not react with iron oxide, so it can also avoid the defects of chemical sand sticking.
2. The thermal conductivity and heat storage coefficient of chromite sand is large (several times larger than silica sand), so the cooling rate is fast, so that the metal on the surface of the casting is cooled quickly, and the surface temperature of the casting is low. At the same time that the melting point is generated in the next step of the molten metal casting process, the material solidifies rapidly as the metal cools rapidly.
Due to the much accelerated cooling rate, an amorphous glass phase is formed between the mold shell and the casting. This glass phase easily falls off from the surface of the casting. Therefore, it is easy to assemble the castings after sand cleaning. The surface finish of the casting after cleaning is high, which avoids sand sticking to the surface.
3. which strengthens the sequential flow of the catalyst metal and improves the production rate. Eliminates the formation of shrinkage cavities and porosity. The quenching process refines the crystal particles of the metal, improves the mechanical properties of the metal, and thereby improves the overall quality of the casting.