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Explanation of commonly used forging processes

In the field of metal processing, forging technology, as an important forming method, is widely used in various fields such as automotive, aerospace, machinery manufacturing, and weapon industry. It uses forging machinery to apply pressure to metal billets, causing them to undergo plastic deformation, thereby obtaining forgings with certain mechanical properties, shapes, and sizes. This article will provide an in-depth explanation of several commonly used forging processes, including free forging, die forging, ring rolling, and special forging, in order to provide reference for practitioners in related industries.

1. Free forging

Free forging is a machining method that uses impact force or pressure to cause deformation of metal between two upper and lower counterweights (anvil blocks). It mainly has two forms: manual forging and mechanical forging. Hand forging relies on the skills and experience of craftsmen and is suitable for the production of small batches and complex shaped forgings. Mechanical forging, on the other hand, utilizes forging equipment such as hammers and hydraulic presses to shape and process billets, making it suitable for mass production.

The advantage of free forging lies in its flexible process, which is suitable for the production of forgings of various shapes and sizes. Meanwhile, due to the three-dimensional compressive stress experienced by the metal during forging, its internal structure is optimized and its mechanical properties are improved. However, the production efficiency of free forging is relatively low and requires high skills from craftsmen.

2. Die forging

Forging is a process of placing a metal blank in a forging die chamber with a certain shape, and obtaining a forged piece by applying pressure to deform it under compression. According to the structure of the forging die and the different forging temperatures, forging can be divided into open forging, closed forging, hot forging, warm forging, and cold forging.

The advantages of forging are high production efficiency, precise forging dimensions, high surface smoothness, and high material utilization. In addition, forging can improve the internal structure of metals and enhance their mechanical properties. However, die forging has high requirements for molds, long design and manufacturing cycles, and high costs.

During the forging process, hot forging is one of the most commonly used methods. It is suitable for the production of large and complex shaped forgings. During hot forging, the metal billet is heated to a certain temperature and then forged to reduce deformation resistance and improve plasticity. Warm forging and cold forging are the future development directions of forging, which can improve the accuracy and surface quality of forgings to a certain extent, while reducing material waste.

Ring rolling is a process method for producing circular parts of different diameters using specialized equipment such as ring rolling machines. It is suitable for producing wheel shaped parts such as car wheels and train wheels. The ring rolling process has the advantages of high production efficiency, high material utilization rate, and precise forging size.

3. Rolling ring

Ring rolling is a process method for producing circular parts of different diameters using specialized equipment such as ring rolling machines. It is suitable for producing wheel shaped parts such as car wheels and train wheels. The ring rolling process has the advantages of high production efficiency, high material utilization rate, and precise forging size. During the ring rolling process, the metal billet is placed in the mold of the ring rolling machine. Through the rotation of the mold and the applied pressure, the metal undergoes continuous local plastic deformation, thereby achieving wall thickness reduction, diameter expansion, and cross-sectional profile forming. The rolling ring process requires high precision in mold design and manufacturing to ensure the dimensional and shape accuracy of forgings.

4. Special forging

Special forging includes processes such as roll forging, cross wedge rolling, radial forging, and liquid forging. These process methods are suitable for producing certain special shaped parts, such as steel balls, drive shafts, large gun barrels, etc.

4.1. Roll forging: 

Roll forging is a process of continuous local plastic deformation of metal billets using two or more rotating rolling rolls. It is suitable for producing slender rods and parts with complex cross-sectional shapes. Roll forging can significantly reduce the subsequent forming pressure and improve the utilization rate of materials.

4.2. Cross wedge rolling: 

Cross wedge rolling is a process method that uses wedge-shaped molds to horizontally roll metal billets. It is suitable for producing shaft parts and gears, etc. Cross wedge rolling can significantly improve production efficiency and reduce material consumption.

4.3. Radial forging: 

Radial forging is a process method that uses radial molds to perform local plastic deformation on metal billets. It is suitable for producing large forgings and thick walled pipes. Radial forging can improve the mechanical properties and dimensional accuracy of forgings.

4.4 Liquid forging: 

Liquid forging is a forming method that falls between die casting and die forging. It is suitable for producing complex thin-walled parts and parts with special properties. Liquid forging combines the advantages of casting and forging, and can significantly improve the mechanical properties and surface quality of forgings.

5. Application and Development of Forging Technology

Forging technology plays an important role in the mechanical manufacturing industry. It can not only provide blanks for mechanical parts, but also improve the internal structure of metals, enhance their mechanical and physical properties. Therefore, forging technology is widely used in industrial sectors such as metallurgy, mining, automobiles, tractors, harvesting machinery, petroleum, chemical, aviation, aerospace, weapons, etc.

With the advancement of technology and the development of manufacturing, forging processes are constantly innovating and improving. On the one hand, people improve forging efficiency and forging quality by improving forging equipment and process methods; On the other hand, people are also exploring new forging materials and forming technologies to meet the demands for forging performance and quality in different fields.

For example, in the aerospace field, in order to meet the requirements of extreme working environments such as high temperature, high pressure, and high speed, new forging materials such as high-temperature alloys and titanium alloys have been developed, and advanced forming technologies such as superplasticity forging and isothermal forging have been adopted. The application of these new materials and forming technologies not only improves the mechanical and heat resistance of forgings, but also reduces production costs and processing cycles.

In addition, with the development of computer technology and automation technology, forging processes have gradually achieved digitization, intelligence, and automation. Through computer simulation and optimization design, people can predict parameters such as deformation, temperature, and stress distribution during the forging process, thereby optimizing process parameters and mold design, and improving the quality and production efficiency of forgings. At the same time, the introduction of automation equipment has also reduced the labor intensity and safety risks of workers, and improved production efficiency and product quality.

6. Conclusion

Forging technology, as an important metal forming method, has a wide range of applications and important positions in the mechanical manufacturing industry. By continuously improving and perfecting forging equipment and process methods, people can produce high-quality and high-performance forgings that meet the requirements of different fields for part performance and quality. At the same time, with the continuous emergence of new materials and forming technologies, as well as the development of computer technology and automation technology, forging processes will also usher in broader development prospects.