What are the defects and reasons for flanging process in stamping?

In stamping processing, flanging process is a common metal forming method, which is mainly used to produce thin-walled parts of various shapes. However, in the actual production process, the flanging process may produce some defects, which affect the quality and performance of the product. In this article, we will introduce these defects and their causes in detail.

Let's take a look at one of the most common defects that can be produced by the flanging process: wrinkling. Wrinkling refers to the phenomenon of uneven deformation of the material in the bending region during the flanging process, resulting in wrinkles on the surface. This phenomenon is mainly due to insufficient plasticity of the material to form the desired curved surface during the flanging process, or due to poorly designed flanging moulds, which result in the material being subjected to excessive squeezing forces during the bending process.

Another common defect that can occur in the flanging process is rupture. Rupture is the sudden breakage of a flanged part when it is subjected to a force, which is usually caused by insufficient tensile strength of the material or by excessive internal stresses generated during the flanging process. In addition, the risk of rupture may be increased if the surface quality of the material is poor, such as the presence of cracks or inclusions.

Edge cracking can also occur with the flanging process. Edge cracking is the appearance of small cracks or breaks on the edges of the part after flanging. This phenomenon is usually caused by poor shape design of the flanging mould or excessive shear stress during the flanging process.

The flanging process may also appear surface quality problems, such as scratches, indentations and oxidation. These problems are usually caused by insufficient surface roughness of the flanging mould, or improper operation during the flanging process.

How to avoid these defects?

Firstly, we need to choose materials with sufficient plasticity to ensure that the ideal surface can be formed during the flanging process. Secondly, we need to design a reasonable flanging mould to ensure that the material is subjected to the right amount of extrusion pressure during the bending process. In addition, we also need to control the shear stress during the flanging process to prevent edge cracking. Finally, we also need to pay attention to the operation process to ensure that the surface of the mould is clean, to avoid surface quality problems caused by improper operation.