In the roll forming of high-strength electric-resistance-welded pipes, the work hardening and springback of strips should be clarified. In this study, the effects of roll type, roll diameter and sheet strength on such operations in a single bending stand are examined by finite element analysis and experiment. Two kinds of roll are used. One (Type A) is a roll stand that pinches strips entirely in the circumferential direction by top and bottom rolls. The other (Type B) is a roll stand that pinches strips only at the edge part of the strips. The springback in Type A is smaller than that in Type B. However, in the case for Type B, overbending occurs owing to the hollow of the bottom roll, and the final circumferential curvature is almost the same as that in the case for Type A. The amount of work hardening in the case for Type A is larger than that in the case for Type B because of the transfer of the longitudinal top roll shape.
