The large-diameter straight seam submerged arc steel pipe is mainly responsible for the pipeline transportation of marine and land oil and gas, oil and natural gas, coal and mineral paddles, etc. It is especially suitable for the “West-East Gas Pipeline” project currently under construction in my country, and can also be used for export and import substitution.
International tube-making technology, process, and characteristics. The forming methods for producing large-diameter LSW steel pipes abroad include the UOE method, CFE row roll forming method, RBE roll forming method, JCOE forming method, C forming method, and PFP step-by-step bending. forming method, etc. A brief introduction is as follows:
1. The UOE method first presses the pre-bending steel plate into a U shape in the forming die of the U press, then presses it into an O shape in the forming die of the O press, and then welds it into a tube and then expands the diameter as a whole. The UOE method is the most advanced forming method in the world. So far, there are nearly 30 sets of such forming welded pipe units in the world. UOE method is famous for its high production efficiency and good product quality, but it is not expensive and has a large investment scale.
2. The row roll forming machine of the CFE method is composed of a pre-forming frame, a flat roll frame, an edge bending roller, and a small row roller frame. Because many identical small row rollers are set, the trajectory of the edge of the steel plate during the forming process is almost It is straight and avoids the phenomenon of “edge stretch”. The CFE method has good forming quality, and its product quality is indistinguishable from the UOF method. This method uses a hot rolled strip coil as raw material, 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-walled steel pipes and large-diameter steel pipes.
3. The RBE roll forming method rolls the steel plate between three rolls or four rolls many times. The welded pipe produced by this method is close to the UOE welded pipe in terms of performance and reliability. The RBE method has less investment, quick plant construction, moderate output, and greater flexibility, and is highly adaptable to the market. 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 roll formed by this forming method, the diameter of the formed steel pipe cannot be less than 508mm (20in) due to the limitation of its rigidity, which reduces the market share. Many pipes in my country have a diameter of less than 508mm.
4. JCOE forming method, first press the steel plate into a J shape on the hydraulic press, after pressing the sides on both sides, it is formed into a C shape by multiple stamping, and finally it is pressed into an O shape by semi-O shape upper die. The product quality of the JCOE method is close to that of the UOE welded pipe, and the price of the operation line is much lower than that of the UOE unit, but its production efficiency is low.
5. The C forming method uses two C forming machines to replace the U press and O press in the UOE unit. The forming process is: the pre-bending steel plate is first formed into half of the steel plate on the press machine, and then in another pressure. The other half of the steel plate is formed on the machine to obtain an O-shaped round tube. The welded pipe produced by the C forming method is of suitable size, has moderate output, and low production line price.
6. The PFP step-by-step bending forming method is to bend the pre-bent steel plate at the end of the press with smaller steps and more times, and finally form it into a round pipe by a steel pipe seam welding machine. The PFP method has a small tonnage of the press due to the small amount of pressing each time, so the investment is also small. This method can form welded pipes with different pipe diameters and different wall thicknesses. The processed diameter can be less than 406mm, and the quality of the produced welded pipes is higher. Well, the yield is moderate.
Post time: Nov-09-2022