1. The casting process usually includes: ①Preparation o […]
1. The casting process usually includes:
①Preparation of molds (containers that make liquid metal into solid castings). The molds can be divided into sand, metal, ceramic, clay, graphite, etc. according to the materials used; they can be divided into disposable and semi-permanent types according to the number of uses And permanent. The pros and cons of mold preparation are the main factors affecting the quality of castings;
②The melting and pouring of cast metal, cast metal (cast alloy) mainly includes cast iron, cast steel and cast non-ferrous alloy;
③ Casting processing and inspection. Casting processing includes removing foreign bodies on the core and surface of castings, removing pouring risers, shoveling burrs and draping seams and other protrusions, as well as heat treatment, shaping, anti-rust treatment and rough machining.
Forging die is a processing method that uses forging machinery to apply pressure to metal blanks to produce plastic deformation to obtain forgings with certain mechanical properties, certain shapes and sizes, and is one of the two major components of forging.
Through forging, the as-cast looseness and welding holes of the metal can be eliminated, and the mechanical properties of forgings are generally better than those of castings of the same material. For the important parts of machinery with high load and severe working conditions, forgings are mostly used in addition to simpler shapes that can be rolled, profiles or welded parts.
1. Forging is divided into forming methods
①Open forging (free forging)
Using impact force or pressure to deform the metal between the upper and lower iron (anvils) to obtain the required forgings, there are mainly manual forging and mechanical forging.
②Closed mode forging
The metal blank is compressed and deformed in the forging die cavity with a certain shape to obtain forgings, which can be divided into die forging, cold heading, rotary forging, and extrusion.
2. According to deformation temperature
Forging can be divided into hot forging (processing temperature higher than the recrystallization temperature of the blank metal), warm forging (below the recrystallization temperature) and cold forging (normal temperature).
Forging materials are mainly carbon steel and alloy steel with various compositions, followed by aluminum, magnesium, titanium, copper, etc. and their alloys. The original state of the material includes bars, ingots, metal powder and liquid metal. The ratio of the cross-sectional area of the metal before deformation to the cross-sectional area of the die after deformation is called the forging ratio. The correct selection of forging ratios has a lot to do with improving product quality and reducing costs.