What Are The Requirements For Stamping Materials

What are the requirements for stamping materials?
The surface and internal properties of stamping sheets have a great impact on the quality of stamping products. The requirements for stamping materials are:
①Precise and uniform thickness
The stamping mold is precise and has a small gap. If the sheet thickness is too large, it will increase the deformation force and cause material jamming, and even cause the die to crack; if the sheet is too thin, it will affect the quality of the finished product, and even cracks will occur during deep drawing.
②Smooth surface, no spots, scars, scratches, surface cracks, etc.
All surface defects will remain on the surface of the finished workpiece. Crack defects may extend deep and wide during bending, deep drawing, forming, etc., resulting in waste.
③ Uniform yield strength, no obvious directionality
Anisotropy (see the appearance of yield in each direction in the process of deep drawing, flanging, bulging and other stamping processes. The plastic deformation of the sheet metal is inconsistent, which will cause uneven deformation, inaccurate forming and defective or scrap products.
④ High uniform elongation
In the tensile test, the elongation before the specimen begins to show the neck phenomenon is called uniform elongation. During deep drawing, the deformation of any area of ​​the sheet metal cannot exceed the uniform extension range of the material, otherwise uneven deformation will occur.
⑤ Low yield strength ratio
The ratio of the yield limit to the strength limit of the material is called the yield strength ratio. Low yield strength ratio The strength ratio can not only reduce the deformation resistance, but also reduce the tendency of wrinkling during deep drawing, reduce the amount of springback after bending, and improve the accuracy of bent parts.
⑥ Low work hardening
The work hardening after cold deformation will increase the deformation resistance of the material, making it difficult to continue to deform, so plates with a low hardening index are generally used. However, materials with a high hardening index have good plastic deformation stability (that is, the plastic deformation is more uniform), and localized cracking is not easy to occur.
In actual production, process tests similar to the stamping process are often used to test the stamping performance of the material, such as deep drawing performance tests, bulging performance tests, etc., to ensure the quality of the finished product and a high pass rate.