Formability of stainles and low carbon steel sheets

Abstract

Formability of steel sheets in metal stamping operationsdepenqs primarily on forming limit strains and uniformity ofstrain distribution. The limit strains are sensitive to strainstate as shown by Forming Limit Diagrams (FLD) . The FLDs of stairless steel sheets were determined by performing simple tensile,notched tensile, Eric~sen, and hydraulic bulge tests. The FLDlevels and shapes differed for austenitic and ferritic stainlesssteel sheets. The FLD of low carbon steel sheet was determinedby a practical method, only by knowing the thickness andyield strength of sheet.The effects of strain hardening exponent, anisotropy ratio,thickness, and lubrication on the formability of stainless stee:were examined and the plastic instability of the sheets were determinedby the strain gradient method.As an industrial application of grid circle(FLD) analysis,an automobile wheel disc production was examined and critical·regions of the disc were determined.