Abstract
Conventional roll forming processes for electric-resistance-welded (ERW) pipes are outlined with respect to roll contours, stand arrangements and deformation strains during forming. The developmental history and features of a new process (VRF process) for forming ERW pipes by constraining the strip edges with undriven vertical rolls are described. The equipment characteristics, fundamental forming characteristics and forming load characteristics of the new process are compared with those of the conventional ER W pipe roll forming processes. Neutral line constant as pass line and uniform displacement distribution as forming distribution are found to be the optimum combination for the VRF process. The results of the present study show that this process can reduce edge stretch and forming energy, and is expected to save roll, equipment and energy costs when put to commercial use. The dimensional tolerances of pipe products manufactured in preliminary commercial production experiments are also described.
