Shape-Controlled Stamping of High-Strength, Hot-Dip Galvanized Steel Sheet

The steel industry has been offering high-strength steel grades for decades to fulfil various customer demands. Our new approach is a high strength hot-dip galvanized steel aiming at a strength level of about 500 N/mm². This material combines high corrosion resistance and high-strength with an increased potential for further material gauge reduction and hence weight savings.

As an example, the designing, stamping and testing of a complicatedly shaped bumper bar are discussed. This features, specifically, the shape control technique used to overcome springback and sidewall curl effects. These springback effects are the result of an unbalanced bending and unbending process while the sheet metal passes over the draw radius. The appropriate balancing of the forming tools has contributed to an extremely robust stamping process, which is desensitised tremendously against the variation in yield strength.