Product Code: ICAL09_P134

Laser Beam Welding of Experimental Trip Steels
Authors:
Ambroise Vandewynckèle, AIMEN; Porrino Spain
Cesar Garcia, AIMEN; Porrino Spain
Daniel Moran, AIMEN; Porrino Spain
Alvaro Prada, AIMEN; Porrino Spain
Patricia Vazquez, AIMEN; Porrino Spain
Presented at ICALEO 2009

In the last few years, the use of Advanced High Strength Steels in the automotive sector has been increasing steadily for the manufacturing of structural and safety parts. Indeed these steels make possible an improvement of passengers safety maintaining a reasonable weight. Five years ago, it was predicted that TRIP steels would be one of the most popular family of AHSS. However nowadays its use is not so significant and generally high strength dual-phase steels or martensitic steels are preferred in spite of the very good forming property of TRIP steels. Probably one of the major reasons is the behaviour of TRIP welded parts, whatever the process. In order to understand better the manufacturing process of TRIP steels as well as their behaviour when forming and welding, the Spanish government is funding a project integrated by 4 members, each one leading a specific part of the study: ITMA is designing and manufacturing the steels, CEIT is selecting the best thermo mechanical cycles, CTM is evaluating the forming properties as manufactured and also of the welded joints, and AIMEN is studying the behaviour of experimental steels when welding. In this paper, the emphasis will be made on the results obtained up to date with the laser welding trials on experimental steels compared to commercial TRIP steels. Welding parameters, microstructure, hardness, strength and formability will be analysed. Some results obtained with resistance spot welding and GMAW will also be presented in order to enable a better understanding of the behaviour of the experimental TRIP steels.