Winner of the Innovation of the Year Steelie Award 2021

Roll stamping is a manufacturing process used to produce automotive parts. Using this method, POSCO has developed the cold-formed automotive Door Impact Beam, leading to a 10% weight reduction and 20% cost savings. Furthermore, the 3.6kg per car of greenhouse gas emissions was reduced by eliminating the heating process and integrating parts.

The Door Impact Beam was developed by taking advantage of the flattening concept. Conventional door impact beams are commonly manufactured by using 1.5GPa post-heat-treated steel pipes. This method requires additional brackets that are welded onto the pipe and the door. While this pipe provides good crashworthiness, the manufacturing costs are exorbitant. POSCO developed the Door Impact Beam by using the combined processes of roll forming and roll stamping to mitigate these disadvantages.

The roll-forming process is followed by roll stamping, which creates the partially flattened region in an in-line process. This partially flattened area is cut and applied to the front and rear brackets. Finally, the pipe and brackets were removed; instead, they were integrated into the single beam component. In lieu of the 1.5GPa post heat-treated steel pipe with 2.0mm thickness and the 780MPa brackets with 1.4mm thickness, POSCO developed the open sectional and cold-formed door impact beam using 1.2GPa steel with 1.0mm thickness.