Advanced High-Strength Steels and Hydroforming Reduce Mass and Improve Dent Resistance of Light Weight Doors In UltraLight Steel Auto Closures Project 2001-01-3116
In May 2000, the UltraLight Steel Auto Closure (ULSAC) Consortium unveiled a lightweight frameless steel door design that achieves 42 percent weight savings over the average benchmarked (1997 model year vehicles) frameless door and 22 percent savings over the lightest benchmark, a framed door. ULSAC was commissioned by this international consortium of 31 sheet steel producers to assist their automotive customers with viable lightweighting steel solutions. The ULSAC design and engineering team, Porsche Engineering Services, Inc. (PES), Troy, Michigan USA, accomplished this significant weight savings by using high and ultra high strength steels, combined with technologies such as tailored blanks and hydroforming. The door outer panel of this first round of demonstration hardware is made of stamped 0.7 mm Bake Hardenable (BH) 260 sheet steel.
During the design and development of the ULSAC frameless door, the ULSAC Consortium evaluated further mass reduction, using sheet hydroforming for the door outer. Consequently, the ULSAC Validation Phase continued beyond May 2000 with sheet hydroforming process development for the door outer as a means to compile practical research documentation for this developmental process with mass reduction potential. Door structures were successfully manufactured with 0.6 mm Dual Phase (DP) 600 hydroformed steel outer panels achieving additional weight savings.