Abstract With the increased demand for application of sustainable materials and lightweight structures, sheet metal forming industry is forced to push existing limits. One area where this particular difficult when it comes assessing formability limit edges. For decades, ISO-16630 Hole Expansion Test (HET) has been standard expressing edge metals through Ratio (HER). However, in recent years, te...

Abstract The use of advanced high-strength steels (AHSS) is associated with increased springback and represents a great challenge for today’s press shops regard to the dimensional accuracy cold-formed sheet metal parts. Springback, its appearance characteristics are mainly dependent on stress state introduced by forming process part geometry before opening tools. With aim determining influence ...

Abstract Stretch flangeability tests are performed on cold rolled AHSS automotive steel grades for crack sensitivity evaluation. The ISO16630 procedure is used with different cutting edge conditions including clearance, tool wear, angle and hole expansion punch geometry. Among all influence parameters, the clearance considered to be most critical control. Low (<10%) high (>20%) clearances...