As a matter of fact, large seam buried arc steel tube can also be used for export and substitution import. It mainly bears the conveying of Marine and land oil and gas, oil and natural gas, coal and mine OARS etc.
Germany's SMSMEER (formerly known as Mannesmann), Japan's NKK, Japan's O.T.K (Osaka Special Steel Pipe Factory), India's WELSPVN Pipe Company, Korea's Hyundai Heavy Industries and Shiya Company, all have their own unique pipe making technology, and are the elite of the international pipe making industry.
The international pipe manufacturing technology, process and characteristics, foreign production of large straight seam submerged arc welding pipe forming methods include: UOE method, CFE row roll forming method, RBE roll bending method, JCOE forming method, C forming method, PFP stepwise bending forming method, etc. A brief introduction is as follows:
1. In UOE method, the steel plate with pre-bent edge is first pressed into U-shape in the forming die of U press, and then pressed into O-shape in the forming die of O press and welded into a pipe, and then the overall diameter is expanded. UOE method is the forming method of current international progress, so far the world already has this kind of forming welding pipe set nearly 30 sets, UOE method is famous for high production efficiency and good product quality, but the equipment price is expensive, the investment scale is large.
2.CFE roller forming machine is composed of preforming frame, flat roll frame, edge bending roll and small roll frame. Because many of the same small roll is set up, the track of steel plate edge in the forming process 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. The raw material of this method is hot roll steel coil, which is different from other forming methods. It is mainly suitable for the production of large quantities and single varieties of steel pipe, but it is difficult to produce high strength thick wall steel pipe and large diameter steel pipe.
3.RBE roll bending forming method rolls the steel plate between three or four rolls for many times. The welded pipe produced by this method is close to UOE welded pipe in service performance and reliability. RBE method has low investment, fast factory construction, moderate output, greater flexibility and strong adaptability 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 part of the forming roller, the diameter of the forming steel pipe can not be less than 508mm (20in), reducing the market share, the diameter of many pipes in our country is below 508mm.
4.JCOE forming method, first press the steel plate into J shape on the hydraulic press, after pressing on both sides, after many times stamping forming for C shape, and finally press into O shape by half O mold. The product quality of JCOE method is close to that of UOE welded pipe, while the price of operation line is much lower than that of 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 as follows: the pre-bent steel plate first forms half of the steel plate on the table press, and then forms the other half of the steel plate on another press, so as to get the O-shaped circular tube. The welded pipe size produced by C forming method is suitable, the output is moderate, and the production line price is low.
6.PFP step by step bending forming method is the end of the pre-bent steel plate in the press with a smaller step, more times to gradually bend the plate, and finally the steel pipe seam welding machine forming a round tube. Due to the small amount of pressing each time, the tonnage of the press is not large in PFP method, so the investment is also small. This method can form welded pipes with different pipe diameters and wall thicknesses, and the processed diameter can be less than 406mm. The welded pipes produced are of good quality and moderate output.
