The effect of mechanical properties on hole flangeability of stainless steel sheets

This study investigates the effect of mechanical properties on hole flange ability of stainless steel sheets. Four different stainless steel sheets, SUS202, SUS304L, SUS316L, and SUS430, with a thickness of 3.0 mm, were evaluated. To estimate the hole flange ability, hole expansion ratio, punch load, flange height, and lip thickness were experimentally investigated. The degree of circumferential strain along the periphery of the expanded hole is important in determining the hole expansion ratio. For materials with higher work hardening exponent and anisotropy, there is an increased resistance in wall thickness reduction, which accelerates local strain concentration along the periphery of the expanded hole in the circumferential direction and lowers hole expansion ratio. The main factors controlling punch load, lip thickness, and height were evaluated through correlation analysis. The flange ability of stainless steel sheets is strongly dependent on both the work hardening exponent and the material anisotropy