Research On The New Technology For Forming The Lage Diamater LSAW Pipes With Four-point Bending JCO Process And CAPP System

With the rapid development of China’s economy, we need more and more oil, natural gas and other energy.And pipeline transportation mode has already become an important part of the energy transport systems. So many large pipe manufacturing companies also have been under rapid development in recent years.Currently, the JCOE/JCO and the UOE pipe technology are more widely applied in the engineering industry, especially the three-point JCO pipe technology, for its advantages in cost, efficiency and forming quality.Based on the study of the traditional JCO forming process, somebody has established the longitudinal-seam submerged arc welded(LSAW) pipe of four-point bending JCO forming theory. This forming process has more significant advantages in terms of costs, efficiency and forming quality. In addition, it needs a smaller number of molds, but get the higher degree of flexibility. Based on the study of the new four-point bending JCO forming process, this paper studies the maximum span of forming mold and its influencing factors and further identifies the key parameters that affect the pipe forming and its rules and method for determining the relevant parameters of the process route according to the result of the study of the maximum span of forming mold.With the rapid development of computer science and technology and its links with the manufacturing sector becoming more and more increasingly close, The Computer Aided Process Planning(CAPP) technology has become an important aid to the process design and determine the process parameters. Based on the theoretical results of the new four-point JCO forming process, the functional requirements for the CAPP system of the large-diameter LSAW pipes new four-point JCO forming process are proposed and its system structure and functional processes are designed. Based on the software development platform of VC++ and combined with the actual production, the process parameters predicting module of tube new four-point JCO forming are researched and developed. And the CAPP system of the new four-point JCO forming process for large-diameter LSAW pipes has been established. Finally, the feasibility and accuracy of the CAPP system to predict forming process parameters has been proved through the simulation and experiments.The results of this paper can provide theoretical and technical support to formulate the forming process parameters of large-diameter LSAW pipes for the plant on actual production. It also get the possibility to reduce the cycle of formulating the forming process parameters and to improve quality and production efficiency of large-diameter LSAW pipes forming for the actual production. Therefore, this study has some potential value for practical application and promotion.