How to Improve the Precision of Precision Stamping and Stretching Parts? Not only should the precision of the stamping die be ensured, but also the use of reasonable die gaps, suitable raw materials, and good equipment. Pay attention to some details as well. Refer to the following detailed information.
Always maintain the cleanliness of the die surface. Before stretching precision stamping parts, the blanks should be wiped clean to prevent dust and other impurities from mixing into the surface or the material surface during the stamping process, which may damage the surface of the metal stamping parts and affect product quality.
2. Increase the hardness of the mold surface appropriately, inspect the mold surface regularly, and clean the waste metal left during the stamping and stretching process, as when the mold hardness is low, waste metal adheres to its surface, causing scratches on the stamping and stretching areas.
3. The rounded corners of molds should also be regularly polished, as the rough surface of the corners can scratch the product surface during stretching.
Expansion:
When producing precision stamping and stretching parts, it's common to encounter product defects such as wrinkling, tearing, and splitting. Due to the varying forces and deformation experienced by different parts during stretching, this can affect product quality and reduce processing efficiency. Let's take a look at these three common issues.
Wrinkles cause significant tangential compressive stress in the flange area during stretching, which exceeds the material's instability resistance. The flange material may bulge due to instability.
2. Stretching and cracking, uneven hardening of metallic materials: After stretching, the material undergoes plastic deformation, leading to cold working hardening. Due to varying degrees of deformation in different parts, the extent of cold working hardening also differs, with the mouth area experiencing greater hardening and the lower parts having less hardening. As the bottom is stretched closer, the cold working hardening is reduced due to smaller tangential compression deformation, resulting in a lower yield limit and strength of the material. Consequently, this area is prone to stretching cracks.
3. Tearing, Uneven Deformation: The thickness of the material varies and is uneven during the stretching process. After the drawing die is formed, the rough material of the workpiece is thicker at the outer edge and gradually thins inward. The material at the bottom, due to friction, becomes thinner, preventing the elongation and deformation of the material. Meanwhile, the bottom corner of the material is always subjected to the impact force and bending action of the punch corner during the stretching process, experiencing tensile stress throughout. This leads to thinning, with the greatest thinning occurring, and the side walls serve to transfer the punch's tensile force to the flange. When the radial tensile stress in the force transmission zone exceeds the material's limit, it will result in fracture.
