Precision forging refers to the forming technology that only needs a small amount of processing or no processing to meet the dimensional accuracy requirements of parts after forging and forming. There are two main ways to achieve precision forging forming: finishing blank, that is, directly forging blank to meet the requirements of precision machining. Precision forging: The whole or some parts are directly processed by precision forging process, thereby reducing the amount of machine addition. At present, there are many precision forging processes used in production. According to the different forming temperature, it can be divided into hot precision forging, cold precision forging, warm precision forging, compound precision forging and so on.

1, Hot precision forging process

Hot precision forging refers to the precision forging process where forging is carried out above the recrystallization temperature. Because the deformation temperature is high, the deformation resistance of the material is low when forging, and the plasticity is good, so it is easy to form parts with complex geometric shapes.

Advantages: The molding effect is good, the high temperature state can be accurately controlled, and the forging can be easier. At the same time, the cost and energy consumption are relatively low.

Disadvantages: Because of heating, the process is more complicated, which is not conducive to energy saving, and the molding accuracy and surface quality are relatively low.

2, Cold precision forging process

Cold precision forging is a kind of precision forging forming technology which is forged at room temperature. Due to the room temperature forming, avoid the size error caused by thermal expansion and contraction, so the shape and size of the cold precision forging workpiece is easier to control, and the surface of the forging does not produce oxidation and burning, etc., with higher surface quality, so the forging accuracy of hot precision forging and warm precision forging is lower than that of cold precision forging.

Advantages: high molding accuracy, good surface quality, no heating, less deformation of materials, good uniformity, less waste of materials.

Disadvantages: requires greater force and cold forging die, high cost and energy consumption, at the same time, the processing speed is slow.

3, Warm precision forging process

Warm forging is a precision forging technique in which metal is heated to a suitable temperature below the recrystallization temperature. It has the advantages of hot forging and cold forging at the same time to avoid their defects, effectively reduce the load of equipment and mold, improve the plasticity and fluidity of the metal, without forging annealing.

Advantages: High molding accuracy and surface quality, at the same time, due to the low temperature of the material, the cost and energy consumption are relatively low.

Disadvantages: The molding speed is relatively low, because the need to use less pressure to form, sometimes the shape limit is relatively large.

4, Composite precision forging process

Composite forging process is a forging technology that combines cold, warm and hot forging processes to complete a workpiece forging. It can play the advantages of cold, warm and hot forging and avoid the disadvantages of cold, warm and hot forging. At the same time, the mechanical properties, dimensional accuracy and surface quality of the parts produced by the composite precision forging process are better than those produced by the single forging technology. At present, the common composite precision forging processes mainly include warm forging - cold finishing, hot forging - cold forging, warm extrusion - cold rolling, warm forging - cold extrusion, hot precision forging - cold rolling and so on.

Advantages: The desired properties and shapes can be achieved by rolling, stretching or shearing at different temperatures and strain rates.

Disadvantages: The cost is relatively high and may not be suitable for projects with smaller production volumes.