1. Gravity casting: sand casting, hard molding. The molten metal is poured into the cavity by the gravity of the metal itself.
2. Pressure casting: low pressure casting, high pressure casting. The molten metal is instantaneously pressed into the casting cavity by an additional pressure.
Casting process usually includes
1 mold (to make liquid metal into a container for solid casting) preparation, the mold can be divided into sand type, metal type, ceramic type, mud type, graphite type according to the materials used, and can be divided into disposable type and semi-permanent type according to the number of times of use. And permanent type, the pros and cons of casting preparation are the main factors affecting the quality of castings;
2 melting and casting of cast metal, casting metal (casting alloy) mainly has various types of cast iron, cast steel and cast non-ferrous metals and alloys;
3 casting treatment and inspection, casting treatment includes removal of core and casting surface foreign matter, refining riser, burr and burr and other projections and heat treatment, shaping, anti-rust treatment and roughing.
The casting process can be divided into three basic parts, namely casting metal preparation, mold preparation and casting processing. Cast metal refers to the metal material used for casting castings in casting production. It is an alloy composed mainly of a metal element and added with other metal or non-metal elements. It is customarily called cast alloy, mainly cast iron. Cast steel and cast non-ferrous alloys.
Metal smelting is not only a simple melting process, but also a smelting process that allows the metal to be poured into the mold to meet the expected requirements in terms of temperature, chemical composition and purity. For this reason, various inspection tests for the purpose of controlling quality are carried out during the smelting process, and the liquid metal can be allowed to be poured after reaching various specified indexes. Sometimes, in order to achieve higher requirements, the molten metal is treated outside the furnace after being discharged, such as desulfurization, vacuum degassing, refining outside the furnace, gestation or deterioration treatment. Commonly used equipment for melting metal is cupola, electric arc furnace, induction furnace, electric resistance furnace, reverberatory furnace and the like.