Hot stamping die design for vehicle door beams using ultra-high strength steel

The energy saving and safety is the eternal theme of development of automobile industry. Ultra-high strength steel automotive body structures of hot stamping have been widely used with these dual advantages that reducing vehicle weight while enhancing safety performance at the same time. The forming and quenching integration die was investigated in this paper with a vehicle door beam as an example, especially the whole die structure and hot stamping process were optimized through numerical simulation of die strength, cooling pipe arrangement and other related factors, and beam samples with tensile strength 1550Mpa, elongation rate 6.5% and shape accuracy of ±0.3mm were produced by this die. Moreover, the stiffness increased by 2.2 times than the original tube beam and 3.8 times of the intensity, which led to full score in C-NCAP Crash Test. By reducing the thickness cross section and the depth of drawing comparing with the original tubular beam, door beam weight could be reduced by 9.32%, which had effective energy-saving and emission-reduction effect.