What are the reasons for springback of precision stamping parts in stamping process

What are the reasons for springback of precision stamping parts in stamping process
The reasons for springback in stamping process are: material function. Within the elastic limit of metal materials, the greater the deformation process and the higher the yield limit, the greater the elastic modulus of the material. In this way, in the process of material processing, the greater the elastic modulus of the material, the greater the springback of bending deformation, and the more serious the work hardening will be. If the elastic modulus of the material is smaller, it will be added The smaller the degree of springback, the stronger the ability to resist elastic deformation.
The larger the bending center angle is, the greater the springback accumulation value is, and the length of workpiece deformation will increase with the increase of bending center angle.
When the mold is designed, it is necessary to leave a gap of twice the material thickness in the relative working part to accommodate the workpiece in the gap. In order to achieve a better flow of materials, the local parts of the mold should be researched and matched after the mold processing. Especially for the bending die, the larger the gap between the working parts, the greater the springback will be. If the tolerance range of the sheet thickness error is larger, the springback will be larger, and the die gap can not be well determined.
The value of the bending radius is proportional to the springback value, so the greater the curvature of the stamping part, the more difficult it is to bend.
The possibility of springback is also different when the shape of stamping parts is different. When a complex bending stamping part is formed in a bending process, due to the mutual restraint of each part of the stamping part and the friction between the die and the material, the stress state of each part of the stamping part will be changed, and the springback amount will be changed.
The forming process of stamping parts is an important aspect to prevent springback value. If the same processing effect is to be achieved in the stamping process of the same batch of stamping parts, the bending force required for correcting bending is much larger than that for free bending. If the same bending force is used in the two methods, the final effect will be different. The larger the correction force is, the smaller the springback of the stamping part is, and the bending force will make the fibers inside and outside the deformation zone be elongated to achieve the forming effect. After the bending force is unloaded, the fiber on the inside and outside will be shortened, but the springback direction of the inner and outer sides is opposite, which makes the springback of the precision stamping parts to a certain extent relieved.