Forging process should be rationally designed

Forging technology In the Ming and Qing Dynasties, Jidong craftsmen forged hoes, knives, kitchen knives, stoves, copper and tin crafts and gold and silver jewellery. During the Qing Emperor Yongzheng period (1723--1735), the "Yangyang Scissors" made by the local earth iron and steel blade forged by the Yongrong forging workers were well-known inside and outside the province. In the 37th year of the Republic of China (1948), Fuding Tongshan opened a repair shop, forging and processing agricultural tools by hand forging, which was the beginning of the forging of small pieces of Jidong. In the late 1950s, forging processing was gradually transformed into machine parts manufacturing. In 1985, Gutian Machinery Factory built the first forging plywood hammer in Jidong, and introduced forging equipment such as 250kg plywood hammer and spring hammer to enhance the mechanization ability of forging. In the 1980s, stamping technology was widely used. In the late 1980s, Jidong Motor Factory adopted a double die and a “triple triple punch” process. The die was fixed and unloaded, and the unloading plate was fixed on the die to ensure accurate stamping position.

The function, structural characteristics and technical requirements of the friction pair material and its selected shaft parts. The blanks of the shaft parts and the common faults of the materials. The use of the transmission gears requires the standard structure and the development of the gear precision standards at home and abroad. And the current quality problem of quenching medium for quenching medium, 120HBMoS, CAE, 0.2%, reasonable design forging process At present, the general enterprise has no sound process laboratory, lacks process test conditions, and objectively requires the process plan to be correct. One success. Especially after entering the market economy, the person in charge of the enterprise required the forging technician to successfully design the forging process.

At present, the general enterprise does not have a sound process laboratory, lacks process test conditions, and objectively requires that the process plan must be correct and successful. Especially after entering the market economy, the person in charge of the enterprise requires that the forging technicians can only succeed and not to fail. This brings great difficulties to the process designers, requiring the craftsmen to have a higher level, but even with rich practice. Experienced craftsmen will inevitably feel troublesome, and once they make mistakes, they will cause large losses.

For a forged piece having an easily tearable portion when trimming, the height of the weak portion of the flash bridge can be intentionally reduced when designing the flash groove to reduce the thickness of the cut here when the fly edge is cut. For example, the S195 connecting rod is made of 45 steel. After forging, the cold-cut edge is used. Because of the small cross-sectional shape and thin material, the lap and the nearby ribs often tear when cutting the edge, and the scrap rate is high. If it is changed to the residual heat cutting after forging, the trimming quality can be improved, but the cutting edge is limited by the tempo of the die forging, and the efficiency is low. When designing the forging die, the height of the fly-side bridge is reduced, and the punching force of the flash edge is reduced, and the tearing of the trimming edge can be greatly reduced.

For the cold extrusion process, it is necessary to maximize the softening of the blank and reduce the frictional force during deformation, and strictly control the degree of deformation and the reasonable distribution of the degree of deformation of each process.

Generally, the softening annealing process of low carbon steel, carbon steel and low carbon alloy steel is: heating to 760 ° C for 4 h, cooling to 680 ° C for 3 h at a cooling rate of 20 ° C / h, and then cooling at a cooling rate of 20 ° C / h After 640 ° C, it was cooled to 350 ° C with the furnace. The hardness generally ranges from 125 to 155 HB.

Carbon steel with a carbon content of less than 0.2%, the hardness of the steel after annealing can be less than 120HB. The steel is softened and annealed and then rolled, pickled, phosphatized, saponified and then coated with lard to lubricate, which can reduce the deformation load and effectively reduce the fracture failure of the punch, the die ring and the joint body.

The cold extrusion method using multiple steps and small deformation can effectively reduce the unit pressing force of the mold, and the blank can be softened without treatment, so that the life of the mold can be prolonged. Some domestic manufacturers are tempted to squeeze the production for a while, reduce the extrusion process, although the sample (or product) can also be made, but the mold load is too large, prone to fracture failure. This kind of quick success is one of the main technical reasons why China's cold extrusion process has not boomed.

Using the forging die CAE software, it is possible to analyze the flow of the material, the frictional resistance and the filling of the material to help the designer to design the process effectively and reasonably.

The function, structural characteristics and technical requirements of the friction pair material and its selected shaft parts. The blanks of the shaft parts and the common faults of the materials. The use of the transmission gears requires the standard structure and the development of the gear precision standards at home and abroad. And the quality problem of quenching medium for the selection of quenching medium for gears.