Finite Element Analysis Of Stress And Deformation In Electron Beam Welding Of Aeroengine Ring Parts

Electron beam welding(EBW)has been widely used in various aeroengine components due to its high energy density and good weld quality.The aeroengine structure is complex and requires high precision and safety of its components,but the residual stress and deformation will inevitably occur in the welding process.Therefore,how to control the residual stress and reduce the welding deformation has become the focus of actual production.In this paper,the combination of numerical simulation and experimental research is used to study the stress and deformation in EBW process of the aeroengine ring parts.The better welding process parameters and welding sequence are explored,and then the optimization scheme is proposed.The results provide theoretical support and reference for the actual welding process of components.Firstly,the orthogonal test of GH4169 superalloy electron beam welding is designed and carried out.By analyzing the morphology,tensile properties and microhardness of welded joints under different welding parameters,a set of EBW parameters suitable for ring parts is obtained,namely accelerated voltage of 60 kV,beam current of 20 mA,welding speed of 20 mm/s.At the same time,a panel finite element model is established according to the actual test conditions.The combined heat source model of the double ellipsoidal heat source and the conical heat source is checked by comparing the test and simulated weld cross-section morphology.Meanwhile,the simulated residual stresses are in good agreement with the measured values.Secondly,the finite element model of the aeroengine ring parts EBW process is established and the stress and deformation during the welding process are calculated.The results show that the area with high residual stress on the component is mainly concentrated in the vicinity of each ring weld.The mean stress of each installed ring weld is higher than that of the inner and outer ring welds.In addition,the cooling process can effectively reduce the stress in the small deformation region,and the effect of secondary heating on the stress reduction is also significant.In the final state,the outer ring presents small deformation,and the inner ring and each installed ring are obviously recessed along the central axial direction,of which the axial displacement peak reaches 0.27 mm.In the radial direction,the outer ring is integrally contracted toward the center of the component,and some of the areas of the inner ring expand outward,but the whole inner ring has a certain degree of deviation towards the direction of later welded area.Finally,the inner and outer ring welding sequence optimization scheme and the installed ring welding sequence optimization scheme are designed respectively,and the calculation results of welding residual stress and deformation of the ring parts under different schemes are compared.The optimization results of the inner and outer ring welding sequence show that the order of welding the outer ring and then welding the inner ring can better control the residual stress in the high stress region and the deformation peak of the component.The optimization results of the installed ring welding sequence show that the "combined symmetrical" welding sequence can control the axial displacement of each ring while keeping the ring welds in a lower stress state,and maintain the dimensional accuracy in the radial direction of the inner and outer rings,which is significantly better than other programs.Therefore,the process of welding the outer ring,then welding the inner ring and then adopting the "combined symmetrical" welding sequence of the installed ring is more suitable for the welding of the ring parts.The process optimization scheme will provide a certain guiding significance for the actual production process.