Abstract: The hot stamping process of an anti-collision beam with ultra high strength was analyzed by simulation. The evolutions of the temperature, thickness, microstructure and mechanical properties of the blank in different stages of hot stamping were investigated. The influences of the process parameters, such as initial forming temperature, punch speed and blankholder force, were studied. Then these parameters were optimized and the results were verified by hot stamping tests. Results show that the blank thickness varies mainly in the stamping stage, while the microstructure and the mechanical properties change mainly in the quenching stages, a little springback occurs after the component is unloaded. The influence of the initial forming temperature on the thickness is obvious, and the formability is poor under low initial forming temperature condition. Both over high and over low punch speeds can cause over reduction of the blank thickness. The blankholder setting reduces the fluidity of the metal greatly, which may bring in cracking. For the beam investigated in this work, the optimum process parameters are initial forming temperature of 800 ℃, punch speed of 100 mm/s, and no blankholder setting.

Key words: materials synthesis and processing technology, ultra high strength steel, hot stamping, process optimization, numerical simulation