Submerged arc welded steel pipe forming methods include continuous torsion forming (HME), continuous roll forming (CFE), Uing-Oing Expanding (UOE), roll bending forming (RBE), and Jing-Cing-Oing Expanding (JCOE), but UOE, RBE, and JCOE are the most widely used.
First, the UOE forming method: The UOE steel pipe forming process is completed in three steps: pre-bending, U-shaped press forming, and O-shaped press forming, followed by cold expansion of the entire pipe to eliminate the stress generated during pipe manufacturing. This forming unit is large and expensive, and each forming piece requires multiple sets of internal and external welding machines, resulting in high production efficiency. Because it is a copy forming process, there are many forming devices; a specific forming mold is needed for each diameter of steel pipe, and these molds need to be changed when changing product specifications. The internal stress of the formed welded steel pipe is relatively large, and a diameter expansion machine is generally provided. UOE (Ultra-Oxide) pipe forming units have mature technology, high automation levels, and reliable products, but require huge investment in equipment and are suitable for large-volume production.
Secondly, the RBE (Reverse Beam) forming method: RBE forming involves rolling, bending, and diameter expansion. The production process is mature. Historically, RB (Reverse Beam) was mainly used to manufacture pressure vessels, structural steel, and water supply and drainage pipes with large outer diameters and short lengths. Because most companies cannot afford the huge investment in UOE pipe forming units, RBE pipe forming units, developed based on RB, have advantages such as lower investment, moderate batch sizes, and convenient product specification changes, thus experiencing rapid development. Welded steel pipes produced using this forming process are close to UOE steel pipes in terms of quality and performance, and therefore can replace UOE welded steel pipes in most cases. RBE pipe forming units use three-roll forming to achieve steel pipe forming. The process involves the three-roll forming machine rolling the steel plate into a steel pipe of a certain diameter, then bending its edges with forming rolls (or performing back-bending). Because it uses a three-roll continuous roll forming process, the stress distribution during steel pipe forming is relatively uniform. However, when changing product specifications, the mandrel needs to be replaced, and the lower roll needs to be adjusted appropriately. One set of mandrels in this forming equipment can handle several product specifications. The disadvantage is the small production scale; due to the influence of mandrel strength and rigidity, the wall thickness and diameter of the steel pipe are greatly limited.
Third, JCOE forming method: JCOE forming has three stages: first, the steel plate is pressed into a J-shape, then successively into a C-shape and an O-shape, where E represents diameter expansion. The JCOE forming pipe-making unit is developed based on the UOE forming process. It borrows the working principle of the U-shape and implements the UOE forming process, greatly reducing the tonnage of the forming machine and thus saving on equipment investment. The produced steel pipes are similar in appearance to UOE welded steel pipes, but the output is lower. This process is easy to automate, resulting in better product formation. JCOE forming equipment can be broadly divided into two types: bending forming and die forming. Bending forming is mainly used for forming thick and medium-thick plates. It has a small step size and low output. The forming process is as follows: First, the two edges of the steel plate are rolled into an arc shape according to the curvature radius of the welded steel pipe on a bending machine. Then, a forming machine presses one half of the steel plate into a C-shape through multiple step-by-step punching. Then, starting from the other side of the steel plate, the other side of the steel plate is also pressed into a C-shape through multiple step-by-step punching, so that the whole steel plate becomes an open O-shape.
Post time: Dec-16-2025