Research On The Large Submarine Pipeline Steel Pipe Continuous Compression Setting Roundness Process By Two Follers

With the decrease of oil and natural gas resources on land, more and more people’s attention move to the ocean, which is giant rich in natural resources. Oil storage capacity of the ocean accounted for 34% of total global oil resources. The exploitation of ocean oil and natural gas, which transportion is mainly dependent on large-scale steel pipeline. Oil pipeline leak and explosion occurred now and then, which cause significant economic losses. For the safety of people’s lives and property, and reduce the probability of accident,it is necessary to improve the quality of large steel pipe.Ovality as one of the standards to measure the quality of pipe, American Association of pipe API Spec 5L standard, ovality of large-scale Longitudinal welded pipe should not exceed 1% of its nominal diameter. But now ovality of almost of large-scale Longitudinal welded pipe which directly product is oval degree than standard range, need to increase a setting round process, the setting round process plays a very important role in the final pipe ovality and the reduction of welding residual stress of pipe.Firstly, do a simple introduction to some setting round process such as the over-bending setting round, three rollers setting round, over-bending setting round process,mould pressing type of compression and setting round, and the advantages and disadvantages of each process. And then introduces the necessity, feasibility and regularity of research the two rollers continuous compression setting round.In this paper, theoretical analysis, finite element simulation and experimental are combinated to study the ovality after two rollers continuous compressing setting round,the factors that impact the ovality, and the law. According to springback theory of small curvature plane bending, theoretical analysis the relationship between process parameters such as on compression ratio, initial ovality and the ovality after setting round, the expression of curvature radius after setting round is established. The finite element software ABAQUS is used to establish the finite element model of the two rollers continuous compression and setting round process, to prove the feasibility of this setting round process. The process parameters and the pipes size are changed to simulate, obtainthe law of two rollers continuous compression setting round. Finally, design the laboratory equipment, and do the experiment, to verify the finite element simulation results.The advantages of this method include the small ovality after setting round, the high production efficiency, the simple equipment structure and easy to realize automatic and intelligent control. The method proposed are helpful to develop the quality and technology of setting round.