Metal stamping parts rebound factor and control method

From the experience of various metal stamping die development and manufacturing, it is known that the drawing die is not easy to handle, because the material will flow, and the problem of stamping and rebounding is sometimes very headache. There is no accurate and reliable rebound calculation. The formula is generally based on experience, for different materials, different R angles to compensate. So what are the factors that affect the rebound of metal stamping parts?
1. Mechanical properties of stamping materials
There are different strength metal stamping parts on the car. From ordinary board to high-strength board, different boards have different yield strength. The higher the yield strength of the board, the more likely it is to rebound, especially the DP series duplex high-strength steel.
2. Stamping part shape and complexity
The rebound of parts with different shapes is very different, and the parts with complex shapes generally increase the order shaping to prevent the rebound from being formed in the form, and some parts with special shapes are more likely to rebound, such as U-shaped parts. In the analysis of the forming process, the rebound compensation must be considered.
3. Stamping material thickness
During the forming process, the thickness of the sheet has a great influence on the bending performance. As the thickness of the sheet increases, the rebound phenomenon will gradually decrease. This is because as the thickness of the sheet increases, the amount of plastic deformation material increases, and the elastic recovery The deformation also increases, so the rebound becomes smaller.
With the continuous improvement of the material strength level of thick Sheet metal parts, the problem of the dimensional accuracy of the parts caused by the rebound becomes more and more serious. The mold design and the later process debugging require an understanding of the nature and size of the part rebound, so as to take Corresponding countermeasures and remedies.
4. Die drawbead
Mold drawbeads are widely used in today's process, and the position of the draw is reasonable, which can effectively change the flow direction of the material and effectively distribute the feed resistance on the press surface, thereby improving the formability of the material and being prone to rebound. The drawing of the ribs on the parts will make the parts more fully formed and the stress distribution more uniform, so that the rebound is reduced.
5. Blanking force of the stripping plate of the mold part
The blanking force forming process of the die stripping plate is an important process measure. By continuously optimizing the blanking force, the material flow direction can be adjusted to improve the internal stress distribution of the material. The increase of the blanking force can make the part drawing more fully, especially the side wall of the part and the R angle position. If the forming is sufficient, the internal and external stress difference will be reduced, so that the rebound is reduced.

How to control the rebound of metal stamping parts?
The best time to reduce or eliminate stamping rebound is during product design and mold development. With the early CAE rebound analysis, the rebound amount is accurately predicted, the product design and process are optimized, and the product shape, process and compensation are used to reduce the rebound. In the metal mold debugging stage, the mold must be tested in strict accordance with the guidance of process analysis. Compared with the ordinary SE analysis, the analysis and correction work of rebound increases by 30% to 50%, but the mold debugging cycle can be greatly shortened.

Rebound is closely related to the drawing process. Under different drawing conditions (tonnage, stroke and feed amount, etc.), although there is no forming problem in the stamping parts, the rebound after trimming will be more obvious, and the rebound analysis and drawing forming analysis will be used. The same software, but the key is how to set the analysis parameters and evaluate the rebound results effectively.

DESHENGRUI Machinery is a professional CNC manufacturing and Sheet metal fabrication company, including CNC machining services, CNC Turning service, CNC milling services, CNC drilling services, laser cutting services, stamping services, Die casting service, iron casting service and Steel Forging service.

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