Effect of Die Hardness and Lubrication on Stamping Performance of One-Side Electrogalvanized and Cold-Rolled Steel Sheet

The automotive industry's efforts to improve the appearance, performance, and corrosion resistance of cars has required the development of new steel products such as USS GALVA-ONE, one-side-electrogalvanized steel, for outer body panels. Stamping plants have discovered that coated steels such as USS GALVA-ONE require different die conditions to successfully make the complex parts formerly made from cold-rolled steels. USS GALVA-ONE, a unique product that is finding increased used in automobiles, appears to be somewhat more sensitive to lubrication and surface properties than cold-rolled steel. Laboratory draw-bead tests showed that a relationship exists between die hardness and lubrication when using USS GALVA-ONE one-side electrogalvanized steel sheet. The study indicated that significant improvements in press performance can be achieved by using hard and polished dies with proper lubrication. Laboratory test performance correlated closely with commercial stamping-plant performance.