Research On The New Technology For Forming The Lage Diamater Lsaw Pipes With Four-point Benting JCO Process

Into the twenty-one century, pipeline construction in China has started to enter thepeak period,oil and natural gas as an extremely major energy plays an increasinglyimportant role in the national economic construction. Pipeline industry in China isincreasing the production pipeline delivery pressure, the development has become thetrend the pipelines moving in the direction of large diameter、thick wall and high strength.especially the JCOE/JCO and the UOE pipe technology that have been extensivelyresearched and applied in the engineering industry. As a representative pipe manufacturingtechnology, the JCO forming process presents the characteristics of low cost, highefficiency and the similar forming quality of the UOE. Therefore, the JCO formingprocess has gained worldwide recognition.Analysis of the routes and process characteristics of UOE and JCOE forming process,based on elaborate four-point bending the JCO forming mechanics principle, proposednew four-point bending JCO forming process and experimental validation. Desigh andexperimental validation of a new process technology. The four-point bending process wassimulated by ABAQUS finite element analysis software. The results show that the processdoes not require pre-bending process, and the residual stress is evenly distributed.In the thesis, I have putted forward the four-point JCO forming process parameters ofthe new process to develop rules, by analyzing the impacts of key parameters on theforming, for example, rebound situation, board width, forming number of times, length offeeding, distance of punch, distance of die, force of JCO forming and stroke of bending.So the thesis has maked the reliable rules of four-point JCO forming. Based on this rule,The typical pipe is widely used is the model of X80steel plate, in the experiment of thethesis, other models steel instead of X80steel plate, the model is SS400steel lpate. Theexperiment show that the ovality meet the engineering application.In conclusion, this study established initially longitudinal-seam submerged arcwelded pipe four-point bending JCO forming process route, proposed the relatedregulations and methodologies, thus providing theoretical and experimental foundation process parameter formulation and mold design in the practice of engineering.