The springback of metal stamping parts is a difficult problem to solve for automobile stamping parts, especially high-strength steel materials with a yield strength of 600Mpa or more. At present, there is no perfect method to cure the springback of stamping parts. We need to solve the springback problem of stamping parts Dig further. So what are the factors that affect the springback of automotive metal stamping parts?

Material Properties

There are stamping parts of different strengths on the car body, from ordinary plates to high-strength plates, different plates have different yield strengths, the higher the yield strength of the plates, the easier it is to rebound. For example, S500MC, DP780 are high-strength steel plates with good cold forming properties.

Material Thickness

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

Part Shape

The springback of parts with different shapes is very different. Parts with complex shapes will generally be reshaped to prevent springback if the forming is not in place, and some parts with special shapes are more prone to springback, such as U-shaped parts. Springback compensation must be considered when analyzing the forming process. At present, European and American customers generally require springback compensation to be handled well in the stamping die process design stage, so that springback should be within the range of product tolerance requirements.

Blindholder Force Of Parts

Blank-holding force The stamping forming process is an important technological measure. By continuously optimizing the blank-holding force, the flow direction of the material can be adjusted and the internal stress distribution of the material can be improved. The increase of the blank holder force can make the part draw more fully, especially the side wall and the R angle position of the part. If the forming is sufficient, the internal and external stress difference will be reduced, thereby reducing the springback.

Drawbead

Drawbeads are widely used in today’s technology. Reasonably setting the drawing position can effectively change the flow direction of the material and effectively distribute the feed resistance on the binder surface, thereby improving the formability of the material. Setting the drawbead on the part will make the part more fully formed, the stress distribution more uniform, and the springback reduced.

Based on the above factors, in order to save the mold adjustment time and reduce the cost of subsequent mold modification, before the stamping process of the automobile mold is determined, it is generally necessary to use CAE simulation software for springback analysis, springback compensation and continuous correction. Commonly used software is Autoform, Danaform and JStamp etc.