Die forging is a kind of excellent processing method, welding crack. According to the model obtained an ideal form of products, but forging will product rebound and overvoltage problems, will affect the product dimension.
Analysis of the impact factors and control methods are:
1, mold factors
Forging die is the product of the shape and size of the high accuracy of the performance of the model after processing. Forging process is the method that all the data and information in the mold will be processed correctly. In the production, the product can not completely achieve the ideal mold shape. Whether it is blank forming forging process or sheet metal forming process is through the elastic deformation and plastic deformation of the material to be processed. The phenomenon of elastic rebound occurs in the process of deformation, but it can not control the phenomenon. Namely the product forming and can not completely reach the shape and size of the mold.
2, the formation process
Springback is processed materials in the pressure of the mold according to the shape of the mold forming, but in the upper and lower mold separation of the moment will be processed products will be more or less the original shape of the direction of the return of more or less. The same phenomenon occurs in the process of drawing and bending. Such as end portion for right angle of 90 degree bending punch and medial angle is 90 DEG bending die bending, bending angle of products is often not possible to reach 90 DEG angles will slightly open, may be 91 DEG or 92, which is rebound phenomenon. If the punch nose radius r doing than to the plate thickness to be small, it is possible to get bending angle is 90 DEG or products. This phenomenon is called the overvoltage phenomenon.
3, control method
At present, there are three ways to prevent rebound phenomenon and overpressure phenomenon in the process of production. One way is to press brake. Bending is the last, to the plate material thickness direction properly applied compressive force, this force can suppress springback phenomenon in bending punch and bending shape of the lower die. Method two is heated bending. The bending material is heated above the recrystallization temperature, and the extension of the material is increased, the hardness is reduced, and the rebound phenomenon can also be played. The three method is cold forming. The cooling liquid is injected into the mold, and the shape is fixed by the sharp cooling of the processed products in the mould. The method basically has no rebound and overpressure phenomenon, and the process of the trimming shape is omitted.