An experimental analysis of drawing characteristics of a dual-phase steel through a round drawbead

The sheet drawing characteristics of a dual-phase steel (DP600) through a round drawbead are determined experimentally using strip drawing tests. For this purpose, a drawbead simulator is designed and integrated with a standard tensile testing machine. Drawing tests are conducted with steel strips cut from 1 mm thickness blanks. The strip geometries, thickness strains, pulling forces and clamping forces are measured during drawing through a round drawbead of 5 mm bead and shoulder radius. The drawbead force parameters and thinning strains are determined from measurements. The experiments are repeated with conventional draw-quality sheets (DC06) of the same thickness for the purpose of establishing a benchmark database. A comparison of calculated drawing characteristics between two types of steels indicates the significant differences in terms of drawbead force parameters. In addition, analysis of experimental data demonstrated bead penetration, clamping force and material flow stress as the dominant factors on drawbead restraint force and blank thinning deformation for both materials. The results of experimental analyzes for both steel types can employed as model input curves for equivalent drawbead models in FE process simulations.