What does work hardening in metal stamping mean? What effect does it have on the stamping performance of the material?

We often hear the term work hardening when we are stamping and processing deep-drawn parts. However, many novices in stamping are not able to understand work hardening in depth, which leads to various types of stamping and deep-drawn parts. The problem. In the process of plastic deformation of metal materials, as the degree of deformation increases, the deformation resistance increases, which makes the strength and hardness of the deformed material increase, while the plasticity and toughness decrease. This is work hardening. Work hardening is an important factor in forming deep-drawn parts. In the process of deep drawing, the sheet metal first produces plastic deformation in the area with low deformation resistance. Due to work hardening, the deformation resistance of the material in this area gradually increases, and the subsequent deformation is transferred to other places, so that deep drawn parts with uniform thickness can be obtained. It can be seen that the sheet material used for stamping and drawing should have a certain hardening ability, and the sheet with weak hardening ability should not be used for drawing. For sheet metal with relatively strong work hardening, the deformation can be made uniform in the same degree of deformation, which can reduce the local thinning of the blank and increase the limit deformation parameters. For the deep drawing of complex-shaped curved parts, the above-mentioned effect is more significant. The disadvantage of work hardening is that the production of work hardening reduces the plasticity of the material and hinders further stamping processing. For example, the punched sheet material will form a layer of surface hardening structure on the surface of the shear zone. This hardened layer is extremely unfavorable for the subsequent processes of the sheet material such as bending, deep drawing, flanging and other processes with large plastic deformation. It can cause cracks or breaks in the workpiece. In multi-pass deep drawing, the semi-finished part will be broken if it continues regardless of work hardening. In order to eliminate work hardening and continue the stamping process, an intermediate annealing process is required. This increases the production cost of stamping parts and prolongs the production cycle. Previous: What do the main technical parameters of the punch press mean?