Free forgings
When forging a free forging, the metal blank is placed between the upper and lower anvils, and then an impact force or pressure is applied to it to deform it. Its biggest feature is that the shape of the forging is mainly shaped by the forging worker's skills and is basically not limited by the die. This forging method is very flexible and can create a variety of forgings, whether they are strange in shape or large in size. Large parts such as large ship crankshafts and turbine main shafts are often made by free forging. Because these parts are large and complex in shape, free forging can better meet their special requirements. However, free forgings also have shortcomings. Its dimensional accuracy is not very high, and the surface is not as smooth as die forgings. This is because it mainly relies on manual operation, and it is difficult to control the size and surface quality as accurately as the die.
Die forgings
The manufacturing process of die forgings is to place the metal blank in a forging die with a specific shape, and then use a press and other equipment to apply pressure to deform the blank in the die, and finally obtain a forging with the same shape as the die. Die forging has many advantages, including high production efficiency, high dimensional accuracy of forgings, good surface quality, and the ability to forge parts with complex shapes. For example, parts such as connecting rods and gears of automobile engines are suitable for manufacturing by die forging because automobile production requires a large number of these parts and has high requirements for their dimensional accuracy and shape consistency. However, die forging also has disadvantages. It requires special molds, and the design, manufacturing and maintenance costs of molds are very high. Moreover, die forging is only suitable for mass production. If it is a single piece or small batch production, the cost is too high and it is not cost-effective.
Ring forgings
Ring forgings are annular workpieces made by forging technology. When it is manufactured, the radial and axial deformation operations of the ring blank are mainly performed, so that the desired ring size and performance can be obtained. Ring forgings generally have relatively high strength and toughness, and are often used in mechanical manufacturing, aerospace and other fields. For example, many parts such as the casing and bearing seat of aircraft engines are ring forgings. Because these parts have to withstand large centrifugal forces and complex mechanical loads when working, the high strength and toughness of ring forgings can meet these requirements. The manufacturing process of ring forgings is relatively complicated, and the deformation degree and direction of the blank need to be precisely controlled to ensure the dimensional accuracy and quality of the ring.
Special forgings
Special forgings are forgings made with special forging processes or special materials to meet some special performance requirements or application scenarios. These forgings may use new materials, such as high-temperature alloys, composite materials, etc.; they may also have very special shapes, such as complex internal cavities, thin-walled structures or asymmetric structures; or they must work in extreme environments, such as ultra-high temperatures, ultra-high pressures, and ultra-high strengths. For example, in the aerospace field, some forgings of rocket engines must withstand extremely high temperatures and pressures, and must be very light and reliable, which are special forgings. These special forgings are usually made of advanced high-temperature alloys, composite materials and other materials, combined with special forging processes such as isothermal forging and powder forging, so as to meet special performance requirements.