Abstract
The numerical simulation of deep drawing processes is state of the art. Beside flow curves and yield locus, friction coefficients for blank-die contact are the most important, but often not exactly known, input parameters. This paper deals with the topic to calculate friction coefficients from Siebel’s formula for calculation of ideal maximum drawing force. Different modifications for special cases e.g. displaced blankholder or big die clearances are taken into account. The modified Siebel formula is used to determine friction coefficients for elevated temperatures up to 600 °C and different dry lubes. The calculated values for the friction coefficients are compared to values identified in numerical simulation.