(1) The FFX forming machine can produce welded pipes with higher steel grade, thinner and thicker walls. Since the deformation of FFX forming technology is mainly based on horizontal rolls, and the vertical rolls in the post-rough forming stage do not need to use inner rolls to control deformation, the equipment structure has the characteristics of both softness and rigidity, and it is easy to achieve high strength and high rigidity and can stabilize Produce high-quality welded pipes above 219 mm, D/t=10 ~ 100, and steel grade up to P110.
(2) Horizontal rolls and vertical rolls of FFX forming machine are fully shared. In FFX forming technology, the involute roll shape and roll-to-roll bending method are organically combined, so that horizontal rolls and vertical rolls can be completely shared. For example, the third-generation ZTF roll-forming machine developed by ZTZG only needs to share a set of rolls for rough forming. It reduces the cost of the roller and simplifies the use and management of the roll.
(3) The distribution of deformation is reasonable and the molding process is stable. In the rough forming stage, the large deformation method mainly adopts horizontal rollers, so that the curvature of the side of the open tube is close to that of the finished welded pipe, and the deformation of the fine forming is small. This reasonable distribution of deformation makes the forming stable and overcomes the disadvantages of row roll forming. The hidden danger of welded pipe defects is caused by the unreasonable distribution of deformation.
(4) The continuous bending forming method is adopted to create the best conditions for high-frequency welding. FFX forming technology adopts the continuous bending forming method and makes full use of the respective forming characteristics of horizontal rolls and vertical rolls so that there is no dead zone of deformation in the strip section, and more importantly, it effectively overcomes the deformation caused by the change of strip thickness and strength. The insufficiently generated elastic recovery phenomenon improves molding accuracy and stability. After rough forming, the edge of the strip steel is completely plastically deformed, and the curvature of the edge of the open tube is very close to that of the finished tube; the deformation of the fine forming is small, and the shape of the open tube after rough forming will not be changed, which creates a great advantage for high-frequency welding. optimal conditions.
(5) Improve the quality of the welded pipe. Compared with the roll forming technology, the FFX forming technology also improves the quality of the welded pipe in the following two aspects: First, after the rough forming, since the curvature of the edge of the open tube is very close to the finished pipe body, it will not be in the finishing stage and Even for high-strength and thick-walled welded pipes, the extrusion rollers produce misalignment during the extrusion stage. After the fine form, the two sides of the edge of the strip are basically parallel (not positive V-shaped or inverted V-shaped) butt joints. Uniform burrs are formed on the inner and outer surfaces of the welded pipe, which is conducive to the scraping of burrs. At the same time, a larger V-shaped welding angle can be used in front of the high-frequency welding machine to effectively prevent welding defects such as gray spots. Secondly, due to the continuous flange forming method and the unique roll pass design, any part of the strip steel section can only bear one deformation at most during rough forming, and the deformation transition is well connected, and it is not easy for a certain part to be deformed for many times. Local thinning occurs due to the pressure of the rolls. Therefore, the deformation is uniform, the internal stress is small, and the internal quality of the welded pipe is improved.
To sum up, FFX forming technology combines many advantages of traditional roll forming and roll forming, and its advancement is very obvious. ZTZG has produced multiple ZTF welded pipe production lines for many enterprises, among which Tangshan Wenfeng Qiyuan Steel designed and produced the fourth-generation FFX automatic forming production line, which realizes computer control, marking that the innovative concept of ZTZG has entered a new stage steps. Our ZTF(FFX) Flexible Forming technology will continue to improve and improve during use.