Historical development and introduction of metal casting


1 The melting point of cast steel is high, and the comp […]

1 The melting point of cast steel is high, and the composition control (such as deoxidation, etc.) is complicated. It is not until 1740 that the method of steelmaking is started, and the development process begins.
2 Cast aluminum In 1886, invented molten salt electrolysis aluminum. By the beginning of the 20th century, the foundry industry for aluminum and its alloys had developed rapidly and ranked first in the casting of non-ferrous metals. The proportion of traditional copper alloy castings has gradually decreased.
Metal casting methods have been developed to meet various needs, and it is possible to economically produce castings of complex shapes and sizes.
The casting properties of metal include: 1 fluidity, the ability of liquid metal to fill the mold; 2 shrinkage tendency, large shrinkage from liquid to solid volume, easy to produce shrinkage and other defects, and large linear shrinkage, affecting the final dimensional accuracy of the casting; 3 hot cracking tendency, some metals and alloys are prone to cracks and segregation tendencies during the casting process.

The metal casting type modeling method is customarily divided into:
1 Ordinary sand casting, including wet sand type, dry sand type and chemical hardening sand type.
2 Special casting, according to the modeling material, can be divided into special castings with natural mineral sandstone as the main modeling material (such as investment casting, clay casting, casting workshop shell casting, negative pressure casting, solid casting, ceramic casting). Etc.) and special castings with metal as the main casting material (such as metal casting, pressure casting, continuous casting, low pressure casting, centrifugal casting, etc.).
Metal casting processes typically include:
1 Casting (contained liquid metal into a solid casting container), the casting can be divided into sand type, metal type, ceramic type, mud type, graphite type, etc. according to the materials used, which 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, cast metal (casting alloy) mainly cast iron, cast steel and cast non-ferrous alloy;
3 Casting treatment and inspection, casting treatment includes removal of foreign objects on the core and casting surface, removal of the riser, burrs and burrs, and heat treatment, shaping, anti-rust treatment and roughing.