Forming Technology and Characteristics of Large-diameter LSAW pipe

The forming process methods of large-diameter LSAW steel pipes include: UOE forming method, JCOE forming method, CFE row roll forming method, RBE roll forming method and C forming method, etc., which are briefly introduced as follows.

1. UOE forming method: After planing or milling the wide and thick steel plate (welding the pilot arc plate before milling), pre-bend the edge on a pre-bending machine, press it into a U-shape on a U-shaped press, and then It is pressed into an O-shaped tube on an O-shaped press. After pre-welding, the tube is sent to several welding lines to weld the inner and outer grooves to form steel pipes. The steel pipe is expanded and sizing, and the dimensional accuracy is improved. After the welding seam passes various inspections, the inner and outer surfaces are coated with an anti-corrosion layer. UOE process equipment chooses steel plate milling machine, pre-bending machine, U-shaped press, O-shaped press, pre-welding machine, internal and external welding machine, pipe expanding machine, non-destructive testing equipment, hydraulic testing machine and steel pipe internal and external coating equipment Wait.
2. JCOE forming method: After the steel plate is pre-bent at the end by the pre-bending machine, half of the steel plate is gradually pressed from one side to the J shape, and then the half is gradually pressed from the side to the C shape, and then formed after the middle pressing The O-shaped open tube blank is welded by a steel pipe welding pre-welding machine, and then welded by an automatic submerged arc internal and external welding machine to become a steel pipe.
3. CFE row roll forming method: the row roll forming machine is composed of a pre-forming frame, a flat roll frame, an edge bending roll and a small row roll frame. Because many small rows of the same rolls are set, the steel plate is formed during the forming process. The trajectory of the edge is almost straight, avoiding the phenomenon of "edge stretching". CFE method has good forming quality, and its product quality is no different from UOF method. This method uses hot rolled strip steel coils as raw materials, which is different from other forming methods. It is mainly suitable for the production of large-scale, single-variety steel pipes, but it is difficult to produce high-strength thick-wall steel pipes and large-diameter steel pipes.
4. RBE roll forming method: roll forming is to roll a steel plate between three or four rolls several times. The welded pipe produced by this method is close to UOE welded pipe in terms of performance and reliability. RBE method The investment is small, the plant is built quickly, the output is moderate and the flexibility is large, and the market adaptability is strong. In recent years, this method has been applied in some developing countries. However, due to the lack of support in the middle of the upper roller of the forming method, due to its rigidity, the diameter of the formed steel pipe cannot be less than 508mm (20in), which reduces the market share. Many pipelines in my country have a diameter below 508mm.

5. C forming method: replace the U press and O press in the UOE production line with two C forming machines. The forming process is: the pre-bent steel plate is first formed into half of the steel plate on the first press, and then The other half of the steel plate is formed on another press to obtain an O-shaped round tube. The welded pipe produced by C forming method is of suitable size, moderate output, and the production line price is low.

Tips: Straight seam steel pipe is a steel pipe whose weld seam is parallel to the longitudinal direction of the steel pipe. Straight seam steel pipes can be divided into high-frequency straight seam steel pipes (ERW Pipe) and submerged arc welded straight seam steel pipes (LSAW) according to the production process. Straight seam welded pipe has simple production process, high production efficiency, low cost and rapid development.

Steel pipe industry practitioners at Permanent Steel Manufacturing Co.,Ltd, knowledge enthusiasts