The effect of die materials on the strain distribution in electro-galvanized sheet steel forming

The punch load and strain distribution of two deformed sheet steels, aluminum killed drawing quality steel (AKDQ Bare) and electro-galvanized drawing quality steel (AKDQ E.G.), are examined under the various process conditions including, die materials, punch speed, blank holding force, drawbead height and lubricant. The punch load and strain distribution ot Bare sheet steel forming is higher than that of E.G.sheet steel on the Kirkesite die set and are reversed on the GM 241 die set. The punch load and strain distribution on the Kirkesite die set is lower than those of the GM 241 die set. The changes of punch load and strain distribution ot the deformed cup for two sheet steels are affected by the frictional behavior of each sheet steel. It shows that the changes of frictional behavior having to be considered in the die design.