①Blank preparation. Chassis forgings have high requirements for blanks, requiring small quality tolerances, small section collapse angles, flat and perpendicular end faces to the billet axis, and no pockmarks, cracks, pits, large scratches or collisions on the billet surface; clean the surface (polishing, pickling, etc.) before forging the chassis forgings. The surface should be cleared of oil, slag, bruises, dents, etc. Aluminum die forging is often used sawing and turning cutting, of which the band saw is more commonly used.

　　② Heating billet. Chassis forgings should be used without oxidation and less oxidation heating method, the heating process should be reduced to the extent of scale.

　　③ fine forging process and press down. In the chassis forgings, crankshaft forging press and forging press or other different equipment can be used for joint die forging. After repeated die forging, finish forging is generally carried out 2~3 times after ordinary die forging, with accuracy up to 0.2~0.3mm and surface roughness value below Ra6.3. In order to achieve higher accuracy size, zui can be cold machined on finishing machine with accuracy 0.1mm and surface roughness value below Ra0.80.

　　④ Inter-process cleaning. Several processes of forging production are inspected and cleaned. Only when the surface defects of the blank are polished or cleaned, the next step of the finishing forging process can be carried out.

　　⑤ Lubrication. Lubrication can make the chassis forging deformation evenly and increase the fluidity of the metal. But lubrication too thin or too thick will bring adverse consequences, lubrication must be moderate.

       Chassis forgings

　　The processing characteristics of chassis forgings are as follows:

　　1. Large weight range. Chassis forgings range from a few grams to hundreds of tons

　　2. The quality of chassis forgings is higher than that of castings. The mechanical properties of forgings are better than castings and can withstand larger impact forces and other heavy loads. Therefore, forgings are used for all important and heavily stressed parts. For high-carbide steels, forgings are better than rolled products in quality. For example, high-speed steel rolled products are forged to meet the requirements of use. Especially HSS milling cutter forging.

　　3. Light weight. Under the premise of ensuring the design strength, chassis forgings are lighter than castings, reducing the weight of the machine itself, which is important for vehicles, aircraft, vehicles, and space and aviation equipment.

　　4. Save raw materials. For example, the crankshaft with static weight of 17kg for automobile, when forging with railway vehicle cutting, the chips account for 189% of the weight of the crankshaft, when forging with die, the chips only account for 30%, and the processing time is shortened by 1/6. chassis forgings can not only save more raw materials, but also save more processing time.

　　5. High productivity of chassis forgings. For example, forging radial thrust bearings with two hot die forging presses can replace 30 automatic cutting machines. When producing M24 nuts with upsetting automatic machine, the productivity of six-axis automatic lathe is 17.5 times.

　　6. The free forging of chassis forgings is highly flexible. Therefore, forging method is widely used in some repair shops to produce various accessories.