# What factors affect the rebound when the section bending machine is working?

## Forwords

Noun explanation: The better the plasticity of the metal material, the stronger the deformation stability, the larger the uniform elongation, the smaller the bending radius.

On the contrary, the plasticity is poor, the bending radius is large, and the material which is particularly brittle and fragile should be annealed or heated and bent before bending.

The bending process is a process of plastic deformation after the material is elastically deformed.

When plastically deformed, the outer layer is stretched, the inner layer is compressed, and the tension and compression cause stress and stress in the material, which causes a certain elastic deformation during the deformation of the material.

When the external force is lost, the material will be certain.

## Springback of section bending parts

The resilience of the profile bending part refers to the profile after plastic deformation，when the bent part leaves the mold,changes in shape and size occur.

The degree of springback is usually expressed by the difference between the actual bending angle of the workpiece and the bending angle of the mold after bending, that is, the size of the springback angle.

The factors affecting springback include the mechanical properties of the material, the relative bending radius, the shape of the workpiece, the mold gap, and the pressure during bending. Since there are many factors affecting springback, the theoretical analysis and calculation are complicated. Generally speaking, the larger the ratio of the inner fillet radius of the bending part to the plate thickness, the greater the springback.

#### So what factors affect the rebound when the profile bending machine is working:

1. The higher the yield strength of the material, the greater the rebound.

2. The ratio of the bending radius r to the material thickness t, the greater the value of r/t.

3. The larger the deformation area, the larger the rebound.

4. The friction between the surface of the material and the surface of the mold affects the stress state of each part of the billet. In most cases, the tensile stress in the bending deformation zone is increased, and the rebound is reduced.