Flange and web profile in stretch flanging - accuracy of formed product in axisymmetric stretch flanging of steel shet II

摘要

The effects of tool dimensions and blank dimensions on the accuracy of a formed product are investigated for the axisymmetric stretch flanging of a cold-rolled steel sheet. A residual bent region remains near the edge of the flange after forming. The outside of the flange except the residual bent region is cylindrical in shape and the outer diameter of the flange is only slightly smaller than that of a die, which is not related to tool dimensions or blank dimensions. The other side, the inner diameter of the flange is not uniform in the axial direction because of the nonuniformity of the thickness reduction. The flange height after forming can be predicted by a simple calculation, taking into consideration the thickness reduction of the flange and drawing of the web. Under the conditions of the present experiment, the warp of the web is generated by the springback of the die shoulder bending, thus it exhibits a concave cone.