The technical methods and characteristics of large-caliber steel pipe pipe making technology. The forming methods of large-caliber steel pipes produced abroad are: UOE method, CFE row roll forming method, RBE roll bending forming method, JCOE forming method, C forming method, PFP step-by-step bending forming method, etc.A brief introduction is as follows：
1. JCOE forming method, the steel plate is first pressed into a J-shape on a hydraulic press, and after the two ends are pressed, it is formed into a C-shape by multiple stamping, and the end is pressed into an O-shape by a semi-O-shaped upper mold.The product quality of the JCOE method is close to that of the UOE steel pipe, and the cost of the working line is much lower than that of the UOE unit, but its production power is low.
2. The C forming method uses two C forming machines to replace the U press and the O press in the UOE unit. The forming process is as follows: the pre-curved steel plate is first formed on the first press. Half of the steel plate is formed, and then the other half of the steel plate is formed on the other press, and then the O-shaped round tube is obtained.The steel pipe produced by the C forming method is suitable for the standard, the output is moderate, and the cost of the production line is low.
3. The PFP step-by-step bending forming method is to bend the steel plate pre-bent at the end in a smaller step size and more times on the press, and gradually bend the sheet material, and the end is formed into a round pipe by the steel pipe joint welding machine.Because the PFP method has a small amount of pressure each time, the tonnage of the press is not large, so the cost is also small. This method can form steel pipes of different pipe diameters and different wall thicknesses. The diameter processed can be less than 406mm, and the steel pipes produced are of good quality and moderate output.
4. The UOE method first presses the pre-curved steel plate into a U-shape in the forming mold of the U press, and then presses it into an O-shape in the forming mold of the O press and welds it into a pipe before expanding the diameter as a whole.The UOE method is one of the leading forming methods in the world today. So far, there are nearly 30 sets of such forming steel pipe units. The UOE method is known for its high production power and good product quality, but it is not expensive and has a large capital investment plan.
5. The row roller forming machine of the CFE method consists of a pre-forming rack, a flat roller rack, an edge bending roller and a small row roller rack. Due to the setting of many identical small row rollers, the trajectory of the edge of the steel plate in the forming process is almost straight, avoiding the appearance of “edge stretching”.The forming quality of the CFE method is good, and the product quality is no different from that of the UOF method.The material used in this method is a hot roller strip steel coil, which is different from other forming methods.It should be suitable for the production of large quantities and single varieties of steel pipes, but it is difficult to produce high-strength thick-walled steel pipes and large-caliber steel pipes.