Forging dies are divided into cold forging dies and hot forging dies according to the deformation temperature of forgings. In addition, there should be a third category, that is, warm forging die; However, the working environment and characteristics of warm forging die are between hot forging and cold forging. Although they also have their own characteristics, they are more similar to hot forging die, and generally no other category is set. In order to explain the use, working environment and characteristics of various types of die and their influence on the production of die forging, cold forging and hot forging die can be further classified according to forging equipment, process methods, processes, die materials and manufacturing methods. This section takes hot forging die as an example to describe as follows:
1. Classification according to forging equipment
According to the type of forging equipment, hot forging die can be mainly divided into hammer (anvil hammer and hammer) forging die, press (mechanical press, screw press and hydraulic press, etc.) forging die, flat forging die and radial forging die.
According to the classification of forging equipment, it is relatively easy to distinguish the purpose, working environment, material type, structural form, size, fixation and positioning mode of the mold. For example, hammer forging die is generally integral, large size, fixed with dovetail and inspection Angle positioning; Press forging die is generally insert type, small size, by oblique wedge clamp fastening and guide column positioning; The forging die is usually a sector insert die.
2, according to the forging process method classification
According to the forging process method, hot forging die can be divided into crude forging die, ordinary forging die, precision forging die, semi-precision forging die, extrusion (punching) die, flat forging die, radial forging die, tire forging die and isothermal forging die, etc.
According to the classification of forging process method, it is easy to distinguish the use, precision, material type, structural characteristics and manufacturing methods of the die. For example, isothermal forging dies for titanium alloys and superalloys need to be manufactured by the precision casting method of superalloys, or even with high melting point metals (such as key alloys).
3, according to the forging process classification
According to the forging process, hot forging die can be mainly divided into blank die, pre-forging die, final forging die, cutting die and correction die, in addition to extruding (punching) die and tire die forging die.
According to the forging process classification can be relatively easy to distinguish the working environment of the die (temperature and stress state), process characteristics, die precision, material type and manufacturing method requirements.
4. Classification according to manufacturing method
According to the manufacturing method, hot forging die can be divided into casting die and forging die; Forging die can be divided into embossing (extrusion) die, cutting and EDM die and surfacing die according to its die chamber processing method. In addition, hot forging die can be divided into several categories according to the type of material.
As can be seen from the above classification of forging dies, different types of forging dies not only reflect the working environment, use, materials, manufacturing methods and characteristics of forging dies, but also reflect the close relationship between forging dies and forging production, which will be discussed in each chapter of this book.