Product Code: ICAL08_1403

Diode Laser Correction of Spring Back Effect in Forming Process of Galvanized Dual Phase Steels for Automotive Application
Authors:
Pablo Romero, Aimen Metallurgical Research Society. Laser Application Center.; Porrino (Pontevedra) Spain
Francisco Rodríguez , Aimen Metallurgical Research Society. Laser Application Center; Porri�O (Pontevedra) Spain
Jacobo Otero, Aimen; Porrino Spain
Joaquín Vázquez, Aimen; Porrino Spain
Gemma Prada, Seat Sa; Barcelona Spain
Idoya Pascual, Gestamp Automocion; Sant Esteve Sesrovires (Barcelona) Spain
Presented at ICALEO 2008

The stringent environmental, safety and economic regulations in automotive industry forced the development of Advanced High Strength Steels (AHSS), but their strongly improved mechanical properties come with some drawbacks in formability, inducing shape uncertainty after the forming process. This work contributes to the efforts in implementing in-shop solutions when forming AHSS, by using laser pre and post treatment. Local laser treatment was performed on galvanized Dual Phase Steel (DP600), in order to reduce the spring back in the production of the B-Pillar reinforcement by stamping. Two different diode laser treatments were studied, tested and compared. After setup and research of optimum parameters, trials were run in a short series of actual real parts from SEAT, and stamping was performed by GESTAMP. The first treatment strategy was performed by combining a specific diode laser scanning sequence on DP steel plates before the forming process, to get local softening without effect on the mechanical performance of the finished component. The second treatment strategy consists in the irradiation with direct diode laser beam applied on strategic radii locations of the formed components, while a clamping force is being applied in the direction of the desired geometrical correction. Dimensional measurements show the spring back reduction in both cases.