Study of deformation and fracture of high strength steel sheet during conventional and robust trimming by conducting partial trimming tests

An instrumented trimming press equipped with D2 grade steel die inserts sharp edges was used to conduct tests on DP980 sheets clearances of 10%, 20%, and 30% the sheet thickness. Trimming were conducted either or without a support pad placed under scrap piece force measured as function penetration distance upper die. The progression plastic deformation fracture processes that occurred in shear affected zone (SAZ) observed polished cross-sections by performing partial tests. During conventional 10% clearance, cracks propagated simultaneously from lower surfaces toward each other. However, when clearance increased 30%, main crack initiated surface resulting formation tensile-type burr. At test prevented bending piece, uniform damage distribution within SAZ. Thus, an improved sheared edge quality is achieved at larger clearances.