Damage in Sheet Metal Bending of Lightweight Profiles

Processes such as air and die bending or roll forming are used to produce bent parts from high-strength steel materials. The results of the first funding period show that damage in sheet metal forming of DP800 dual-phase steel depends to a large extent on the stress state during forming. The reduction of damage leads to an increase in the performance of bent parts in terms of absorbed impact energy, stiffness, and fatigue strength.

The overall objective of the current second funding period is to understand the interaction of damage mechanisms under hydrostatic and deviatoric stress path changes in DP800 and to control the damage. For this purpose, the process chain of profile production is considered, where a straight profile is produced by roll forming or by air bending and then curved by three roll push bending or rotary draw bending. In the area of hot sheet forming, the damage-critical influences during press hardening of 22MnB5 are also identified.