What is the forging process?

Different forging methods have different processes, among which hot die forging process is the longest, and the general sequence is:

Forging blank blanking; Forging blank heating; Roll forging preparation blank; Die forging forming; Cutting edge; Punching; Correct; Intermediate inspection, inspection forgings size and surface defects; Heat treatment of forgings to eliminate forging stress and improve metal cutting performance; Cleaning, mainly to remove the surface oxide skin; Correct; Check, general forgings to go through the appearance and hardness inspection, important forgings after chemical composition analysis, mechanical properties, residual stress and other tests and non-destructive testing.

Forging is one of the two components of forging (forging and stamping), which uses forging machinery to exert pressure on metal blank and make it produce plastic deformation to obtain forgings with certain mechanical properties, shapes and sizes. Through forging, defects such as loose as cast can be eliminated in the process of metal smelting, and the microstructure can be optimized. At the same time, the mechanical properties of forgings are generally better than those of castings of the same materials because the complete metal streamline is preserved. Related machinery in high load, severe working conditions of the important parts, in addition to the shape of the simple available rolled plate, profile or welding parts, the use of forgings.

Forging classification

classification

1. Aircraft forging

2, diesel engine forging

3. Marine forging

4. Weapon forging

5, mine forging

6. Nuclear power forging

7. Petrochemical forgings

Forging class

As mentioned above, it can be divided into hot forging, warm forging and cold forging according to the forging temperature.

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

1. Free forging. It refers to a forging process that uses simple universal tools or directly exerts external forces on the blank between the upper and lower anvil iron of forging equipment to deform the blank and obtain the desired geometry and internal quality. The forgings produced by free forging method are called free forging. Free forging mainly produces forgings in small batches. Forging equipment such as forging hammer and hydraulic press is used to form and process blanks to obtain qualified forgings. The basic processes of free forging include upsetting, drawing, punching, cutting, bending, twisting, shifting and forging. Free forging adopts hot forging mode.

2. Die forging. Die forging is divided into open die forging and closed die forging. The metal blank is obtained by compression deformation in the forging die bore with a certain shape. Die forging is generally used to produce parts with small weight and large batch.

Die forging can be divided into hot die forging, warm forging and cold forging. Warm forging and cold forging are the future development direction of die forging and also represent the level of forging technology.

According to the material, die forging can also be divided into black metal die forging, non-ferrous metal die forging and powder product forming. As the name suggests, the materials are carbon steel and other ferrous metals, copper and aluminum and other non-ferrous metals and powder metallurgy materials.

Extrusion belongs to die forging, which can be divided into heavy metal extrusion and light metal extrusion.

Closed die forging and closed heading forging are two advanced processes of die forging. Because there is no flying edge, the utilization rate of materials is higher. It is possible to finish complex forgings with one or several processes. Since there is no flying edge, the forgings have less force area and less load required. However, it should be noted that the blank can not be completely restricted, so it is necessary to strictly control the volume of the blank, control the relative position of the forging die and measure the forging die, and try to reduce the wear of the forging die.

3. Roll the ring. Roller ring refers to the production of ring parts with different diameters by special equipment roller ring machine, which is also used to produce wheel shaped parts such as car hub and train wheels.

4. Special forging. Special forging includes roll forging, cross wedge rolling, radial forging, liquid die forging and other forging methods, which are more suitable for the production of some special shape parts.

For example, roll forging can be used as an effective preforming process to significantly reduce subsequent forming pressure; Cross wedge rolling can produce steel ball, transmission shaft and other parts; Radial forging can produce large - scale forgings such as gun barrel and step shaft.