Metal casting is a process of melting metal into a liquid that meets certain requirements and pouring it into a mold. After cooling, solidification and cleaning, castings with predetermined shapes, sizes and properties are obtained. Because the billet is almost formed, the purpose of no processing or a small amount of processing is achieved, and the cost and time are reduced to some extent. Casting is one of the basic processes of modern machinery manufacturing industry.

The modeling methods of metal casting types are customarily divided into: ① ordinary sand casting, including wet sand mold, dry sand mold and chemically hardened sand mold. ② Special casting, according to the molding materials, can be divided into special casting with natural ore as the main molding material (such as investment casting, clay casting, shell casting in casting workshop, negative pressure casting, full mold casting, ceramic mold casting, etc. ) and special casting with metal as the main mold material (such as metal mold casting, pressure casting, continuous casting, low pressure casting, centrifugal casting, etc. ). The metal casting process usually includes: ① Preparing molds (containers for making solid castings from liquid metal), which can be divided into sand molds, metal molds, ceramic molds, clay molds, graphite molds, etc. According to the times of use, it can be divided into disposable mold, semi-permanent mold and permanent mold, and the quality of mold making is the main factor affecting the quality of castings. (2) Melting and pouring of casting metals, casting metals (casting alloys) mainly include cast iron, cast steel and casting nonferrous alloys; (3) Casting processing and inspection. Casting treatment includes removing foreign bodies from the core and the surface of the casting, cutting off the riser, shoveling off burrs, overlapping seams and other protrusions, as well as heat treatment, shaping, rust prevention and rough machining.