Casting is a kind of hot working technology for metal, and it has about 6,000 years' history. Foundries are mainly tools that mainly used in agricultural production, daily life and religion. Fork toe also has a long history. There are some differences between casting and forging.
 
Definition
Casting is to make the shapeless metal liquid into solid with certain shape. Forging is to change the shape of the solid.
 
Processing method
Casting is to pour metal liquid into mold cavity, and after solidification the liquid will form the required shape. While forging is to put the heating metal to the mold cavity, and then give some stress to force the metal to the desired shape.
 
Classification
Casting has many classifications. According to moulding technics, casting can be divided into gravity casting (including sand casting and die casting) and pressure casting (including low pressure casting and high pressure casting). According to different modeling methods, casting can be divided into sand casting process and special casting process. While sand casting process includes green sand mold, dry sand mold and chemical hardening sand mold. As for different Forging parts supplier, special casting process can also be divided into special casting process that uses natural minerals as modeling materials (including investment casting, clay mold casting, negative pressure casting, full-mold casting and ceramic mold casting) and special casting process that uses metal as main modeling materials (including permanent mold casting, pressure casting, continuous casting, low pressure casting and centrifugal casting). According to the movement pattern, forging can be mainly divided into open die forging and die forging. While die forging can also be divided into closed-die forging and no-flash die forging. According to the deformation temperature, forging can be divided into hot forging, warm forging and cold forging.
 
Raw material
Investment casting plant for casting includes gray pig iron, spheroidal graphite cast iron, malleable cast-iron, carbon steel, alloy steel, bronze, aluminium alloy, stainless steel and so on. Brittleness material can not be used in forging, while forging needs plastic material. These raw materials for forging include medium and low carbon steel, alloy steel, copper, copper alloy, aluminium alloy, magnesium alloy, titanium alloy, stainless steel and so on.
 
Technological process
Casting process has three parts: the preparation of casting metal (take aluminum sand casting for example, you should prepare aluminium alloy beforehand), the preparation of casting mould and post treatment of sand casting parts. Forging technology is more complex. Take hot die forging for example, the process includes gropping of forging billet, heating forging billet, roll forging, metal forging, trimming, punching, correction, intermediate survey, check sizes and surface, heat treatment, cleaning, restriking, checking. So, casting is fully fashioned, while forging forming need several times.
 
Defect
Melted liquid metals need to fully fill the mold cavity at first, and then cool down, so in the casting process, air hole can easily occur. Forging is done under the high temperature, so forging can refining grain.