2 Forging advantage is obvious, conform to the equipment for lightweight & high strength requirements
Forged iron is stronger, more ductile and more economical, propelling mankind into the Iron Age.
The strength and toughness of wrought iron are higher than that of bronze, so it is more suitable for the manufacture of cold weapons. The toughness and ductility of iron itself are higher than that of copper, and the strength of the material can be enhanced through repeated forging of iron blocks at high temperature. Under the same strength, the toughness of iron is much better than that of bronze. The cold weapons of the Bronze Age are mostly made into short swords with thrust type, while the cold weapons of the Iron Age became popular for chopping knives. In addition, forging technology requires high ductility and toughness of metal. As the main forging material, the discovery and large-scale use of iron also promoted the development of forging technology.
The relative abundance of iron in the earth's crust is higher than that of copper, which is more economical. When the abundance of iron in the crust is greater than tin and copper, the origin is relatively low. Due to the high cost of copper itself, bronze was mainly used for ceremonial vessels and weapons in the Bronze Age, and could not completely replace stone tools as the main production tool. Iron completely replaced stone tools as the main production tools because of its economy, which further promoted the development of forging technology.
Metal forming process classification: casting, plastic forming, machining, welding, powder metallurgy, metal injection molding, metal semi-solid forming, 3D printing and so on. Among them, casting and forging the longest history, the most widely used.
Compared with casting and machining, forging has advantages in the integrity of parts, texture streamline, flexibility of parts and so on.
Plastic forming optimizes metal properties by changing metal microstructure. After plastic deformation, metal materials not only change shape and size, but also change a series of internal structure and properties. The microstructure of metal materials will change significantly. In addition to a large number of slip bands and twin bands, the grain transfer will also change, that is, each grain will be elongated or flattened along the direction of deformation, and the internal structure of the metal will change, thus optimizing the properties of the metal.
Forging also provides structural integrity unmatched by other metalworking processes. The main raw materials for forging metal bars, ingot and so on. These raw materials in its smelting, casting and crystallization process, inevitably will produce porosity, shrinkage and dendritic crystal and other defects, therefore, the casting process is difficult to make up for the need to withstand impact or alternating stress working environment parts (such as transmission spindle, ring, connecting rod, rail wheel, etc.). Forging eliminates internal voids and cavitation that weaken metal parts. Forging provides excellent chemical uniformity by dispersing segregation of alloys or nonmetals. Predictable structural integrity reduces part inspection requirements, simplifies heat treatment and machining, and ensures optimal part performance under on-site load conditions.
The grain characteristics of forging determine the directional toughness of forging parts. By mechanically deforming the heated metal under strict conditions, forging refines the coarse grains and results in dense metal structures, leading to predictable grain sizes and flow characteristics. In practice, by pre-machining the forgings, the dendritic structure of the ingot can be improved and the hole gap can be eliminated, and the mechanical properties of the forgings can be improved. This quality translates into superior metallurgical and mechanical qualities and provides better directional toughness in the final part.
Forges have the best metal texture flow. Forging is under the action of pressurizing equipment and working (die) tools, the billet or cast ingot produce local or all plastic deformation, in order to obtain a certain geometric size, shape of the parts (or blank) and improve its organization and performance of the processing method. After forging, the metal material has good shape and size stability, uniform texture, reasonable fiber structure and the best comprehensive mechanical properties.