Expanding the forming limits of DP780 by adjusting ram slide motions on a mechanical servo press

Advanced high strength steels (AHSS) are increasingly being employed in the manufacturing of car body parts to counterbalance the weight gain from safety features, comfort features, and heavy batteries or hybrid powertrains. However, AHSS tighten the process window in deep drawing operations. For this reason, this paper extends the forming capability of the AHSS DP780 by adjusting the ram slide motion (RSM) of a mechanical eccentric press with a servo drive. To accurately analyze the impact of the RSM, a deep drawing tool for research purpose with a cross geometry is used. For each process setting, the maximum achievable drawing depth is determined and subsequently analyzed to identify the RSM parameters with highest and lowest impact. The results are critically discussed in terms of correlation and causality.