The factors affecting stamping springback are:

Stamping material properties

There are automobile stamping parts with different strengths on the car. From ordinary plates to high-strength plates, different plates have different yield strengths. The higher the yield strength of the plates, the more prone to rebound. For example, S500MC, DP780 and other high strength steel plates with good cold forming performance.

2. Stamping material thickness

During the forming process of metal stamping, the thickness of the sheet material has a great influence on the bending performance. As the thickness of the sheet material increases, the rebound phenomenon will gradually decrease. This is because as the thickness of the sheet material increases, the materials involved in plastic deformation increase. Furthermore, the elastic recovery deformation also increases, and therefore the springback becomes smaller.

3. Shape of stamped part

The springback of parts with different shapes is very different. Generally, parts with complex shapes will be added with a sequence of reshaping to prevent springback when they are not formed in place, and some parts with special shapes are more prone to springback, such as U-shaped parts. In the analysis of the forming process, the springback compensation of the stamping die must be considered. At present, customers in Europe and the United States generally require that springback compensation should be handled well in the stamping die process design stage, and the springback should be within the product tolerance requirements.

4. Blank holder force of blank holder of automobile mold

The blanking force stamping process is an important process measure. By continuously optimizing the blanking force, the material flow direction can be adjusted and the internal stress distribution of the material can be improved. Increasing the blank holding force can make the part more fully drawn, especially the side wall and the R angular position of the part. If the forming is sufficient, the difference between internal and external stress will be reduced, and the springback will be reduced.

5. Automotive die drawing ribs

Drawing bars are widely used in today's technology. Reasonably setting the drawing position can effectively change the material flow direction and effectively distribute the feeding resistance on the press surface, thereby improving the material formability. The setting of draw bars on the parts will make the parts more fully formed and the stress distribution more uniform, thereby reducing the rebound.

Based on the above factors, in order to save the time for adjusting the mold of the automobile and reduce the cost of subsequent modification, before the stamping process of the automobile mold is determined, it is generally necessary to use CAE simulation software to perform springback analysis, and to perform springback compensation and continuously modify. Autoform, Dynaform and JStamp.