Sand sticking of steel castings is an old problem. At present, the commonly used anti sticking sand materials include chromite sand, zircon sand, magnesia and olive sand. The former two are expensive, while the latter two have limitations. In the current situation of fierce market competition, in addition to casting quality, casting price is one of the most important factors, and reducing casting cost has always been the purpose of enterprises. Therefore, it is still the goal of foundry workers to find an effective and low-cost anti sticking sand material. This article mainly introduces the composition and properties of fused ceramic sand and its application in high manganese casting core sand. Through comparison, it can achieve the same anti sticking effect as chromite sand, but it has an advantage in reducing the cost, so it can replace chromite sand in the use of high manganese steel casting core sand.
Why High Manganese Steel Parts Need New Materials
Crawler shoes and bucket teeth are made of high manganese steel. Silica sand was used as the core sand material of high manganese steel castings before, but because silica sand is an acid refractory, its composition is mainly SiO2, however, high manganese steel contains more MnO2, which belongs to alkaline oxide. It is easy to cause sand sticking in production, which not only takes time to clean up, but also affects the critical cooling rate of heat treatment, and ultimately affects the austenitizing degree of castings. Carbide remains at the grain boundary, which becomes the root cause of cracks. Based on the above problems, we choose chromite ore to replace silica sand. Chromite sand is an alkaline refractory material with high refractoriness and thermal conductivity several times larger than silica sand. It has a good effect of resisting alkaline slag, so it can effectively prevent sand sticking defects of castings. But it is expensive and needs to be imported from abroad. Therefore, it is of great significance to find new materials to replace chromite ore in reducing costs.
Introduction to Fused Ceramic Sand
Fused ceramic sand is a kind of artificial molding sand, which is made of high-quality calcined bauxite. It has excellent performance and is a neutral material, which can be applied to various casting alloys and various casting processes. Fused ceramic sand has high temperature resistance, good thermal stability, not easy to break, and good regeneration.
With these properties, there is possibility and necessity to take a trial and use ceramic sand on high manganese steel parts.