First, let's first understand what sand is. Sand is divided into mechanical sand and chemical sand. Chemical sand is a part of the container or a layer of metal oxide adhered to the whole surface. The hardness is high. Only grinding wheel can grind it. go with. Generally, the surface sanding of the packaging barrel is caused by the oxidation of molten steel. The traditional casting coating only acts as a barrier between the container and the mold to achieve the purpose of anti-sticking sand, but sometimes it is also stuck in the container part or large area. This is because the high-temperature liquid metal is oxidized to form a metal oxide, which produces ferrous silicate, so the fluidity is very good. Even if the surface of the casting has a solidified shell, the newly formed ferrous silicate is still liquid, and it is easy to penetrate into the paint. Sand-type pores.
How to solve this problem?
1. In response to this phenomenon, we must ensure that the wall thickness of the container is uniform when producing the packaging drum, and the radius of the fillet can be appropriately increased to minimize the hot pitch circle and the cold iron is used.
2. Correctly select the original sand particle size, the surface sand and the adhesive have a higher degree of refractoriness, or increase the quality of the molten metal, and appropriately reduce the pouring temperature and pouring speed.https://www.fhpails.com/