Warmforming: novel concepts for efficient manufacturing in the automotive industry aiming at vehicle lightweighting
Project co-financed by European Economic Area Agreement (EEA Grants): Supported by a grant from Iceland, Liechtenstein and Norway.
The scope of this project consists on the development of a new steel forming process at temperatures that do not affect to the internal structure phase of the steel. Some of the advantages of the warmforming process could be the following ones:
- Possibility to manufacture more complex shapes in order to improve stiffness of the parts and reduce weight
- Use of protected sheets (zinc coating, oiling) to avoid scaling
- Heating the steel up to 600ºC without changing the phase if the material, thus improving the stamping feasibility
- Better forming tolerances due to reduced spring back
CONCLUSIONS OF THE PROJECT
This project has been mainly focused on complex phase hot rolled steels because they are more common materials for chassis manufacturing (CP800 and CP1000).
The optimum temperature for warmforming is 600ºC, bellow this value the elongation of the materials is lower than at room temperature. At
this temperature the internal structure phase of the steel does not change and the stamping feasibility is improved.
The aging effect that materials could suffer during warmforming process is an important factor to consider. It is not recommended to heat a material twice, because cracks could appear during its transformation.
The trials done with some materials such as CP800, have been more successful in cold stamping than in warmforming. The use of oil could avoid cracks during the semi hot stamping process of CP800.
Some cracks produced with CP1000 material in cold stamping could be avoided using warmforming process. However, repetitive warmforming operations could lead to seizing of the tooling.
The applicability of this new technology has been demonstrated on certain operations of the manufacturing process of a Lower Control Arm. The mechanical tests done on manufactured parts show an increase in strength and decrease in elongation after the warmforming process. Beneficiary:
AUTOTECH Engineering A.I.E. www.gestamp.com Location:
Parque Empresarial P2-A4,
Biscay (Spain) Contact:
Pedro Díaz Gaviria
Phone:+34 94 450 77 00