Springback in Roll Forming Processes of High-Strength Steel Sheets

— Finite-Element Simulation of Roll Forming of Seam Welded Pipes (1st report) —

Abstract

To produce electric resistance welded pipes using high-strength steel sheets, it is very important to accurately predict the amount of springback in roll forming processes. In this study, the three-dimensional deformation behavior of sheets at a single bending stand consisting of vertical rolls with a circular profile is investigated in detail using the static-implicit finite element program Marc. The calculation results are in good agreement with the experimental results. The amount of springback in roll forming processes is much smaller than that predicted by the theoretical analysis of plane strain bending. It is found that the small springback is due to the reduction in bending moment caused by tensile deformation in the circumferential and longitudinal directions followed by compressive deformation in the circumferential direction in the later stage of roll forming processes.