Influence of Necking Process in Stamping

There are many processing procedures in the processing of stamping parts. This article introduces the necking process. Necking refers to a forming process that narrows the mouth of a pre drawn tubular blank or cylinder of a metal stamping part through a necking die. It is widely used. Next, let’s look at the influence of necking process on metal stamping parts.

During necking processing, the metal stamping material at the necking end slides into the female die under the pressure of the punch, the diameter decreases, the wall thickness and height increase, and when the wall thickness of the workpiece is not large, it can be approximately considered that the deformation area is in the plane stress state of tangential and radial compression, mainly tangential pressure. The radial compressive strain is the large strain of zui, while the thickness and length directions are elongation, and the deformation in the thickness direction is greater than that in the length direction.

Due to the effect of tangential compressive stress, the billet is prone to instability and wrinkling during necking; At the same time, the cylinder wall in the non deformation area is prone to instability and deformation due to bearing all necking pressure, so preventing instability is the main problem of necking process.