The process of melting the metal into a liquid that meets certain requirements and pouring it into the casting mold, and obtaining castings (parts or blanks) with predetermined shape, size and performance after cooling and solidification and cleaning treatment. The basic technology of modern machinery manufacturing industry. The blank cost of casting production is low, and it can show its economy for parts with complex shapes, especially those with complex cavities. At the same time, it has wide adaptability and good comprehensive mechanical properties. However, the materials required for casting production (such as metal, wood, fuel, molding materials, etc.) and equipment (such as metallurgical furnaces, sand mixers, molding machines, core making machines, sand knocking machines, shot blasting machines, etc.) are more, and will produce dust, harmful gases and noise and pollute the environment.

Casting is one of the earliest metal hot working processes mastered by humans, which has a history of about 6,000 years. Bronze frog castings appeared in Mesopotamia in 3200 BC. Between the 13th and 10th centuries BC, China has entered the heyday of bronze castings, and the process has reached a very high level, such as the 875 kg Simu Wu square tripod of the Shang Dynasty, the Zeng Hou Yi plate of the Warring States and the light mirror of the Western Han Dynasty are representative products of ancient casting. The early casting was greatly influenced by pottery, and the castings were mostly tools or utensils for agricultural production, religion, life and other aspects, and the artistic color was strong. In 513 BC, China cast the world's earliest recorded cast iron - Jin State cast Tripod (about 270 kg). Around the 8th century, Europe began to produce cast iron. After the industrial Revolution in the 18th century, castings entered a new period of service for large industries. Into the 20th century, the development of casting speed is very fast, has developed ductile iron, malleable iron, ultra-low carbon stainless steel and aluminum copper, aluminum silicon, aluminum magnesium alloy, titanium base, nickel base alloy and other casting metal materials, and invented a new process for gray cast iron inoculation treatment. After the 1950s, there were new processes such as wet sand high-pressure modeling, chemical hardening sand modeling and core making, negative pressure modeling, and other special casting and shot blasting.

There are many kinds of casting, according to the modeling method is customarily divided into: ① ordinary sand casting, including wet sand, dry sand and chemical hardening sand 3 categories. ② Special casting, according to the modeling materials can be divided into natural mineral sand as the main modeling materials of special casting (such as investment casting, mud casting, casting workshop shell casting, negative pressure casting, solid casting, ceramic casting, etc.) and metal as the main casting materials of special casting (such as metal casting, pressure casting, continuous casting, low pressure casting, centrifugal casting, etc.) two categories. Casting process usually includes: ① casting (make liquid metal into solid casting container) preparation, casting according to the material used can be divided into sand, metal, ceramic, mud, graphite, etc., according to the number of use can be divided into disposable type, semi-permanent type and permanent type, the quality of casting preparation is the main factor affecting the quality of castings; 2 Casting metal melting and casting, casting metal (casting alloy) mainly cast iron, cast steel and cast nonferrous alloys; (3) Casting treatment and inspection, casting treatment includes removal of core and casting surface foreign bodies, cutting out the pouring gate, shovel grinding burrs and seams and other protrusions, as well as heat treatment, shaping, anti-rust treatment and roughing.