Lehrstuhl für Fertigungstechnologie, Universität Erlangen-Nürnberg

Laser Assisted Bending of High Strength Multi Phase Steels

Datum: 10.05.2005



  • Prof. Dr.-Ing. Dr.-Ing. E.h. mult. Dr.h.c. M. Geiger
  • Prof. Dr.-Ing. T. Schuöcker, TU Wien

The aim of this project is to extend the material caused forming limits by the bending process of high-strength steel sheets, which are difficult to form, by a local heating up of the sheet in the zone of the bending line. For that purpose the highstrength multi-phase steels, the complexphase steel CP-W800 and the martensitephase steel MS-W1200 should be bend laser assisted up to 180³ with a preferably small bending radius. The enlargement of the bending angle by the laser assistance can be achieved with both steel grades. By the martensite-phase steel the maximum bending angle can be increased by the laser assistance of more than 200%. The maximum bending angle at room temperature at the not irradiated sheet surface is α20°C=43° and at a temperature of 678°C at the not irradiated sheet surface the maximum bending angle is α678°C=133°. The reason for the increase of the maximum bending angle is the thermal activation of additional sliding systems and the structure change of the steel. The laser assistance makes it possible to increase the maximum bending angle of complex-phase steel of 85%. Bending the complex-phase steel at room temperature enables only a maximum bending angle of 72° without any crack. By the laser assisted bending at a temperature of 783°C at the not irradiated sheet surface a bending angle of 134° can be achieved.