New Approach for Spring-Back Compensation in Die Design - Application on Industrial Parts in High Strength Steel

In the car industry, the carmakers are confronted more and more with the phenomenon of spring-back after stamping and especially with the use of new high strength steels (HSS and VHSS). Since several years, Renault and Arcelor work together on the formability and spring-back of VHSS and since two years, they were interested to establish a methodology in order to determine the good die shape which allows to compensate the spring-back after stamping. A methodology, named “Outifo” has been developed in order to obtain by simulation, from the initial CAD's of the part and his referential stamped die, a CAD of a die with a modified shape. This allows the real stamped part, after forming and spring-back, to recover as close as possible the geometry of the theoretical part defined by the designer.