Forming Technology Of Large-diameter And Thick-wall Tube

In this paper, the main forming process from the pre-bending to the volume is studied for the aim of large-diameter thick-wall tube transport oil and gas. By process analysis and finite element simulation, the springback of plate is analyzed focus, at the same time, pipe-line measurement system is designed.The molding pre-bending mode applied to thick plate is analyzed and simulatied under two different conditions. One is under involute circle shape of the mold, and the other is under arc mold shape. The two curve equation calculated by the shape after springback indicates that involute circle shape of the mold should be taken. The influnces of the base circle radius of mold, pre-bending width and the raise of die model on springback are founded through orthogonal and range analysis. The corresponding relationship between pre-bending roll angle that directly affect the quality of the pre-bending parameters and various factors above is studued.The process and characteristics of multi-pass progressive bending(JCO Act) is analyzed in detail. The pipe forming process is divided into several steps, and only part of the plate is bent during each step. The requirements of the equipment capacities are reduced due to the lower bending force. Designing orthogonal experiments with the factors including punch radius, die radius, die opening volume and the depth of punch into the die, analyzing their impact on the rebound values by the use of finite element software Marc. After determinating the most optimal mode parameters combination, anti-launch the pipe bend parameter of a given radius pipe by calculating the corresponding of the depth of concave mold into the punch and the radius after rebound.In the whole circle roundness tube links, in order to improve the diameter measurement of the efficiency and accuracy for measuring the characteristics of requirements, a pipe-line measurement system which includes hardware and software in two parts is designed. A large number of experiments are done with the two sensors separately in order to calibrate sensor accuracy, the experimental data are recorded and analyzed. The law of the sensors'systems are founded and the correction are calculated through analasing the datas. The pipe-line measurement system is proved to meet the production requirements by field experiments.In this paper, the analysis and simulation of pre-curved molding and multi-pass progressive bending in the large-diameter thick-walled tube production process are the most advanced technology in the field. This provides guiding significance for the actual production.