1. Gravity casting: sand casting, hard casting. The molten metal is poured into the cavity by gravity of the metal itself.
2. Pressure casting: low pressure casting, high pressure casting. The molten metal is instantaneously pressed into the casting cavity with an additional pressure.
① the mold (the liquid metal into a solid castings of the container) to prepare, according to the use of materials can be divided into sand, metal type, ceramic type, mud type, graphite type, according to the number of times can be divided into one- And the permanent type, the merits of the preparation of the mold is the main factor affecting the quality of castings;
② casting metal melting and casting, casting metal (casting alloy) are mainly cast iron, cast steel and cast nonferrous metals and alloys;
③ Casting treatment and inspection, casting processing, including removal of core and casting surface foreign body, remove the riser, shovel burr and lichen and other protrusions and heat treatment, plastic surgery, rust treatment and rough processing.
Casting process can be divided into three basic parts, namely, casting metal preparation, casting preparation and casting treatment. Casting metal refers to the casting production for the casting of metal materials, it is a metal element as the main component, and add other metal or non-metallic elements and the composition of the alloy, commonly known as casting alloy, mainly cast iron, Cast steel and cast nonferrous alloys.
Metal melting is not just a simple melting, but also includes the smelting process, so that the metal into the mold, in terms of temperature, chemical composition and purity are in line with the expected requirements. To this end, in the smelting process to control the quality of the purpose of the various inspection tests, liquid metal to meet the required indicators to allow casting. Sometimes, in order to achieve higher requirements, the metal liquid after the baked but also by the furnace treatment, such as desulfurization, vacuum degassing, furnace refining, inoculation or deterioration treatment. Smelting metal commonly used equipment cupola, electric arc furnace, induction furnace, resistance furnace, reverberatory furnace and so on.
1, can produce complex shape parts, especially the complex cavity of the rough;
2, wide adaptability, industrial commonly used metal materials can be cast, a few grams to several hundred tons;
3, a wide range of raw materials, low prices, such as scrap, scrap, chips, etc.;
4, the shape and shape of the casting is very close to the parts, reducing the amount of cutting, are no cutting;
5, widely used, agricultural machinery 40% to 70%, 70% to 80% of the machine weight are cast.
1, mechanical properties such as forgings, such as tissue thick, defects and more;
2, sand casting, single, small batch production, the labor intensity of workers;
3, casting quality is not stable, more processes, influential factors are complex, easy to produce many defects.
Casting defects on the quality of castings have an important impact, therefore, for the choice of casting alloy and casting methods to lay the foundation, starting from the quality of castings, combined with the formation of major defects in the formation and prevention.