Forging is a processing method that uses a forging machine to apply pressure to a metal blank to plastically deform it to obtain a forging with certain mechanical properties, certain shape and size, and is one of the two major components of forging (forging and stamping).

Through forging, defects such as as-cast looseness produced by the metal during the smelting process can be eliminated, and the microstructure can be optimized. At the same time, due to the preservation of the complete metal streamline, the mechanical properties of forgings are generally better than those of castings of the same material. For important parts with high load and severe working conditions in related machinery, forgings are mostly used in addition to rolling plates, profiles or welded parts with simple shapes.

According to the forming mechanism, forging can be divided into free forging, die forging, ring rolling and special forging.

Features of free forging:

Improve organizational structure and improve mechanical properties. Through forging, the internal coarse-grained structure of the metal is broken: defects such as pores, shrinkage holes, and cracks are pressed together to improve the compactness, and the metal fiber streamlines are reasonably distributed on the section of the forging, which improves the mechanical properties of the metal.

Low cost and reasonable economy. Forging equipment and tools have good versatility, and the production preparation cycle is short, which is convenient for product replacement.

The process is flexible and adaptable.

Forgings have low dimensional accuracy.

Free forging is mainly used in the production of single-piece small batches, forgings with less complex shapes and low dimensional accuracy requirements, as well as some large-scale forgings.

Free forging equipment:

Air hammer Simple structure, flexible operation, easy maintenance but small hammering force

Hydraulic machine, hydraulic machine is to plastically deform the billet under static pressure, work smoothly, with low noise, good working conditions, and generate large pressure, but the equipment is huge, the structure is complex, and the price is expensive.

Both types of equipment have no problem of overload damage, but if the tonnage of the equipment is selected too small, the forging will not be penetrated inside, and the productivity will be low. On the contrary, if the tonnage of the equipment is selected too large, it will waste manpower and financial resources.

The selection of forging equipment is mainly related to factors such as deformation area, forging material and deformation temperature.

It can be used for thickening, drawing, punching, reaming, bending, shifting, etc.

Determination of initial forging temperature: On the premise that heating defects such as overheating and overburning do not occur, the initial forging temperature should be increased as much as possible to make the metal have good forgeability. The initial forging temperature is generally controlled at 150-250 ℃ below the solidus line.

Die forging is divided into open die forging and closed die forging

Definition of die forging: The method of forging the heated billet in the die fixed on the die forging equipment is called die forging. Die forging is the main method of forging using special forging dies to obtain forgings of the desired shape and size.

The characteristics of die forging are: under the action of the forging press, the blank is forced to flow plastically in the forging die cavity, so as to obtain forgings with better quality than free forging.