Study On The New Forming Process Of Welded Pipe And Rollers Design

Compared with project practice, the theoretical and experimental study on the forming process of welded pipe is scarcely done and it is also very difficult to solve it in the finite element method, because the process is multi-nonlinear coupled problem that includes large deformation elastic plastic and nonlinear contact, till now the entire numerical simulation study on it has not been done. In the practice,the experimental designing method is still used in the design of the forming precess of longitudinal welded pipe and foming mill,then the rationality of forming process and rollers designed in the way has to be verified through production practice,which leads to high cost production and long period production,finally can not meet the requirements of the market economy development.In the paper the non-linear finite element methods that include large deformation elastic plastic and nonlinear contact and multi-physics FEA software—ANSYS are used to generally construct three-dementional finite element model of forming process of small diameter longitudinal welded pipe,the forming process of blank for welded pipe in the single stand and multi-stand rollers is simulated and researched,in the simulation the stress and strain distributing and changing rules , curvature and rolling force changing rules in the blank for welded pipe are obtained.In the simulation the fixed bottom line single radius forming process ,the down hill single radius forming process and the down hill double radius forming process are considered,the influence of different forming processes and the blank wall thickness to stress ,strain and curvature is also studied,and the influence of rolling force to forming process is also considered. The study on the different forming methods shows that tri-radius froming method is more suitable for the edge forming than single-radius and double radius forming methods.Based on the numerical simulation results,the design method on the new forming process of middle diameter welded pipeΦ219x6 is putted forward,the deformation and rollers configuration figures are designed and drawed,the structure and dimensions of the first stand horizontal rollers are detailedly designed with tri-radius combination roller shape.Finally an ecomical and high-efficiency design method that combines the experimental design and numerical simulation is adviced.In this paper the study results provide reference for the design of roll-pass, roller profile and forming process. These are also a base to improve the quality of welded pipe and realize the transformation of welded pipe design method from experimental design to numerical simutation design.