Numerical Simulation And Process Optimization Of Arc Welding Forming Pressure Wessel In Deformation Research

With the rapid development of modern petrochemical industry,pressure vessels have been widely used in various industries and even become the main equipments in production.Pressure vessel is influenced by certain pressure when used,and it often works in a high temperature and high pressure,corrosion,vacuum environment.In the event of danger,the casualties and economic loss and environmental pollution caused by such consequences are incalculable.Therefore,the requirements to the pressure vessel production and safety performance are very strict.Welding is one of the main technologies in the production process of pressure vessels.Welding deformation often causes fatigue damage of pressure vessels,which greatly affects the service life of pressure vessels.Therefore,it is one of the key problems to effectively control and reduce the welding deformation of pressure vessels.In this paper,the study object is a medium-pressure Steam condensate tan in 2-class which will be produced by a pressure vessel manufacturer in Karamay.Using the Visual-Environment software with a double-ellipsoidal heat source model to call Sysweld solver,the welding deformation simulation analysis is carried out.The simulation results of temperature field and stress deformation field of pressure vessel are obtained by numerical simulation.It can be seen from the distribution cloud map of temperature field that the molten pool always presents an ellipse along the welding direction,which is consistent with the preset double ellipsoid heat source.As the number of weld passes increases,the heat is accumulated layer by layer,and the maximum temperature of each layer is increased.The uneven temperature field causes the residual stress of welding concentrated in the weld area,and the concentrated distribution of residual stress causes the deformation of pressure vessel greatly.After the welding of the pressure vessel tube,it was found that the maximum straightness error of the tube was 1.4249 mm and the roundness error was 1.5828 mm,both of which are within the allowable range.The maximum total deformation of pressure vessel is 1.6308 mm.In order to further reduce the welding deformation,improve the production quality and efficiency,the welding processes of pressure vessel are optimized in this paper.Through the optimization of the welding sequence,the welding starting point and the multi-dimension,find that the maximum welding deformation of the pressure vessel is 1.4336 mm,which significantly reduced the welding distortion after the multi-dimensional optimization.