The Roundness Profile Resulting from a New Adjustable Ironing Punch

The ongoing push for increased flexibility in high-volume metal forming tools often implies increased complexity in design and control, and new phenomena in the forming processes. In common industrial sheet metal forming operations, variations in raw material properties, such as thickness, strength, and anisotropy, makes achieving precise product geometry a challenging task. In this study, a dimensional analysis was performed on EN 1.4404 cups ironed with a novel adjustable ironing punch, as presented by Nielsen et al. [ 1]. Three cups with different strategies were ironed, revealing a difference in roundness profiles. Tool geometry imperfections were found to have no impact on the cup wall roundness. The R-value of the sheet material was measured in a uniaxial tensile test in three directions and the planar anisotropy gave rise to uneven thickening of the cup wall in deep drawing. This, combined with the reduced plastic deformation during the retraction of the novel ironing punch changes the roundness profile of the cup.