Agile Tube Roll Forming, a New Process Architecture for Manufacturing of Longitudinally Welded Tubes

. Thick-walled longitudinally arc-welded tubes are indispensable in modern infrastructure owing to their exceptional load-bearing capacity and structural integrity. Nevertheless, their fabrication remains highly challenging, as the conventional forming forces demand the use of large-scale industrial presses. To address this limitation, this research introduces a novel process architecture that integrates agile tube roll forming process for tube manufacturing, thereby enabling the production of such tubes using significantly smaller and more flexible manufacturing systems. To this end, three tube support configurations—namely, support-less, dynamic roller support, and static support—were systematically investigated in this study on 7, 9, 11, and 15 mm thick 304 stainless steel. While the supportless condition represents the most economical option, the incorporation of dynamic or static support significantly improves geometric accuracy, yielding near-net cross-sections combined with reductions in tube ovality of approximately 75 and 79 %, respectively, compared to support-less configuration. Considering the straightness of the weld line as a quality indice, the dynamic support provides the highest quality. Using the static/dynamic support strategies, the deformation forces arise between 2 and 3 times compared to support-less strategy.